Skip to Content
Version 15.14 by Helena on 2025/05/22 16:14
Show last authors
1 (% contenteditable="false" tabindex="-1" %)
2 (((
3 (% class="macro" data-macro="startmacro:box|-|title=~"**Contents**~"|-|\{\{toc/}}" data-widget="xwiki-macro" %)
4 (((
5 (% class="macro-placeholder hidden" %)
6 (((
7 macro:box
8 )))
9
10 (% class="box" %)
11 (((
12 (% class="box-title" %)
13 (((
14 **Contents**
15 )))
16
17 (% class="macro" data-macro="startmacro:toc|-|" %)
18 (((
19 (% class="macro-placeholder hidden" %)
20 (((
21 macro:toc
22 )))
23
24 (% class="wikitoc" %)
25 * [[1 Purpose and Structure>>doc:null||anchor="H1PurposeandStructure"]]
26 ** [[1.1 Purpose>>doc:null||anchor="H1.1Purpose"]]
27 ** [[1.2 Structure>>doc:null||anchor="H1.2Structure"]]
28 * [[2 General Notes on This Document>>doc:null||anchor="H2GeneralNotesonThisDocument"]]
29 * [[3 Guide for SDMX Format Standards>>doc:null||anchor="H3GuideforSDMXFormatStandards"]]
30 ** [[3.1 Introduction>>doc:null||anchor="H3.1Introduction"]]
31 ** [[3.2 SDMX Information Model for Format Implementers>>doc:null||anchor="H3.2SDMXInformationModelforFormatImplementers"]]
32 *** [[3.2.1 Introduction>>doc:null||anchor="H3.2.1Introduction"]]
33 ** [[3.3 SDMX-ML and SDMX-EDI: Comparison of Expressive Capabilities and Function>>doc:null||anchor="H3.3SDMX-MLandSDMX-EDI:ComparisonofExpressiveCapabilitiesandFunction"]]
34 *** [[3.3.1 Format Optimizations and Differences>>doc:null||anchor="H3.3.1FormatOptimizationsandDifferences"]]
35 *** [[3.3.2 Data Types>>doc:null||anchor="H3.3.2DataTypes"]]
36 ** [[3.4 SDMX-ML and SDMX-EDI Best Practices>>doc:null||anchor="H3.4SDMX-MLandSDMX-EDIBestPractices"]]
37 *** [[3.4.1 Reporting and Dissemination Guidelines>>doc:null||anchor="H3.4.1ReportingandDisseminationGuidelines"]]
38 **** [[3.4.1.1 Central Institutions and Their Role in Statistical Data Exchanges>>doc:null||anchor="H3.4.1.1CentralInstitutionsandTheirRoleinStatisticalDataExchanges"]]
39 **** [[3.4.1.2 Defining Data Structure Definitions (DSDs)>>doc:null||anchor="H3.4.1.2DefiningDataStructureDefinitions28DSDs29"]]
40 **** [[3.4.1.3 Exchanging Attributes>>doc:null||anchor="H3.4.1.3ExchangingAttributes"]]
41 ***** [[3.4.1.3.1 Attributes on series, sibling and data set level >>doc:null||anchor="H3.4.1.3.1Attributesonseries2Csiblinganddatasetlevel"]]
42 *** [[3.4.2 Best Practices for Batch Data Exchange>>doc:null||anchor="H3.4.2BestPracticesforBatchDataExchange"]]
43 **** [[3.4.2.1 Introduction>>doc:null||anchor="H3.4.2.1Introduction"]]
44 **** [[3.4.2.2 Positioning of the Dimension "Frequency">>doc:null||anchor="H3.4.2.2PositioningoftheDimension22Frequency22"]]
45 **** [[3.4.2.3 Identification of Data Structure Definitions (DSDs)>>doc:null||anchor="H3.4.2.3IdentificationofDataStructureDefinitions28DSDs29"]]
46 **** [[3.4.2.4 Identification of the Data Flows>>doc:null||anchor="H3.4.2.4IdentificationoftheDataFlows"]]
47 **** [[3.4.2.5 Special Issues>>doc:null||anchor="H3.4.2.5SpecialIssues"]]
48 ***** [[3.4.2.5.1 "Frequency" related issues>>doc:null||anchor="H3.4.2.5.122Frequency22relatedissues"]]
49 * [[4 General Notes for Implementers>>doc:null||anchor="H4GeneralNotesforImplementers"]]
50 ** [[4.1 Representations>>doc:null||anchor="H4.1Representations"]]
51 ** [[4.2 Time and Time Format>>doc:null||anchor="H4.2TimeandTimeFormat"]]
52 *** [[4.2.1 Introduction>>doc:null||anchor="H4.2.1Introduction"]]
53 *** [[4.2.2 Observational Time Period>>doc:null||anchor="H4.2.2ObservationalTimePeriod"]]
54 *** [[4.2.3 Standard Time Period>>doc:null||anchor="H4.2.3StandardTimePeriod"]]
55 *** [[4.2.4 Gregorian Time Period>>doc:null||anchor="H4.2.4GregorianTimePeriod"]]
56 *** [[4.2.5 Date Time>>doc:null||anchor="H4.2.5DateTime"]]
57 *** [[4.2.6 Standard Reporting Period>>doc:null||anchor="H4.2.6StandardReportingPeriod"]]
58 *** [[4.2.7 Distinct Range>>doc:null||anchor="H4.2.7DistinctRange"]]
59 *** [[4.2.8 Time Format>>doc:null||anchor="H4.2.8TimeFormat"]]
60 *** [[4.2.9 Transformation between SDMX-ML and SDMX-EDI>>doc:null||anchor="H4.2.9TransformationbetweenSDMX-MLandSDMX-EDI"]]
61 *** [[4.2.10 Time Zones>>doc:null||anchor="H4.2.10TimeZones"]]
62 *** [[4.2.11 Representing Time Spans Elsewhere>>doc:null||anchor="H4.2.11RepresentingTimeSpansElsewhere"]]
63 *** [[4.2.12 Notes on Formats>>doc:null||anchor="H4.2.12NotesonFormats"]]
64 *** [[4.2.13 Effect on Time Ranges>>doc:null||anchor="H4.2.13EffectonTimeRanges"]]
65 *** [[4.2.14 Time in Query Messages>>doc:null||anchor="H4.2.14TimeinQueryMessages"]]
66 ** [[4.3 Structural Metadata Querying Best Practices>>doc:null||anchor="H4.3StructuralMetadataQueryingBestPractices"]]
67 ** [[4.4 Versioning and External Referencing>>doc:null||anchor="H4.4VersioningandExternalReferencing"]]
68 * [[5 Metadata Structure Definition (MSD)>>doc:null||anchor="H5MetadataStructureDefinition28MSD29"]]
69 ** [[5.1 Scope>>doc:null||anchor="H5.1Scope"]]
70 ** [[5.2 Identification of the Object Type to which the Metadata is to be Attached>>doc:null||anchor="H5.2IdentificationoftheObjectTypetowhichtheMetadataistobeAttached"]]
71 ** [[5.3 Report Structure>>doc:null||anchor="H5.3ReportStructure"]]
72 ** [[5.4 Metadata Set>>doc:null||anchor="H5.4MetadataSet"]]
73 * [[6 Maintenance Agencies>>doc:null||anchor="H6MaintenanceAgencies"]]
74 * [[7 Concept Roles>>doc:null||anchor="H7ConceptRoles"]]
75 ** [[7.1 Overview>>doc:null||anchor="H7.1Overview"]]
76 ** [[7.2 Information Model>>doc:null||anchor="H7.2InformationModel"]]
77 ** [[7.3 Technical Mechanism>>doc:null||anchor="H7.3TechnicalMechanism"]]
78 ** [[7.4 SDMX-ML Examples in a DSD>>doc:null||anchor="H7.4SDMX-MLExamplesinaDSD"]]
79 ** [[7.5 SDMX Cross Domain Concept Scheme>>doc:null||anchor="H7.5SDMXCrossDomainConceptScheme"]]
80 * [[8 Constraints>>doc:null||anchor="H8Constraints"]]
81 ** [[8.1 Introduction>>doc:null||anchor="H8.1Introduction"]]
82 ** [[8.2 Types of Constraint>>doc:null||anchor="H8.2TypesofConstraint"]]
83 ** [[8.3 Rules for a Content Constraint>>doc:null||anchor="H8.3RulesforaContentConstraint"]]
84 *** [[8.3.1 Scope of a Content Constraint>>doc:null||anchor="H8.3.1ScopeofaContentConstraint"]]
85 *** [[8.3.2 Multiple Content Constraints>>doc:null||anchor="H8.3.2MultipleContentConstraints"]]
86 **** [[8.3.2.1 Cube Region>>doc:null||anchor="H8.3.2.1CubeRegion"]]
87 **** [[8.3.2.2 Key Set>>doc:null||anchor="H8.3.2.2KeySet"]]
88 *** [[8.3.3 Inheritance of a Content Constraint>>doc:null||anchor="H8.3.3InheritanceofaContentConstraint"]]
89 **** [[8.3.3.1 Attachment levels of a Content Constraint>>doc:null||anchor="H8.3.3.1AttachmentlevelsofaContentConstraint"]]
90 **** [[8.3.3.2 Cascade rules for processing Constraints>>doc:null||anchor="H8.3.3.2CascaderulesforprocessingConstraints"]]
91 **** [[8.3.3.3 Cube Region>>doc:null||anchor="H8.3.3.3CubeRegion"]]
92 **** [[8.3.3.4 Key Set>>doc:null||anchor="H8.3.3.4KeySet"]]
93 *** [[8.3.4 Constraints Examples>>doc:null||anchor="H8.3.4ConstraintsExamples"]]
94 * [[9 Transforming between versions of SDMX>>doc:null||anchor="H9TransformingbetweenversionsofSDMX"]]
95 ** [[9.1 Scope>>doc:null||anchor="H9.1Scope"]]
96 ** [[9.2 Groups and Dimension Groups>>doc:null||anchor="H9.2GroupsandDimensionGroups"]]
97 *** [[9.2.1 Issue>>doc:null||anchor="H9.2.1Issue"]]
98 *** [[9.2.2 Structural Metadata>>doc:null||anchor="H9.2.2StructuralMetadata"]]
99 *** [[9.2.3 Data>>doc:null||anchor="H9.2.3Data"]]
100 *** [[9.2.4 Compact Schema>>doc:null||anchor="H9.2.4CompactSchema"]]
101 * [[10 Validation and Transformation Language (VTL)>>doc:null||anchor="H10ValidationandTransformationLanguage28VTL29"]]
102 ** [[10.1 Introduction>>doc:null||anchor="H10.1Introduction"]]
103 ** [[10.2 References to SDMX artefacts from VTL statements>>doc:null||anchor="H10.2ReferencestoSDMXartefactsfromVTLstatements"]]
104 *** [[10.2.1 Introduction>>doc:null||anchor="H10.2.1Introduction"]]
105 *** [[10.2.2 References through the URN>>doc:null||anchor="H10.2.2ReferencesthroughtheURN"]]
106 *** [[10.2.3 Abbreviation of the URN>>doc:null||anchor="H10.2.3AbbreviationoftheURN"]]
107 *** [[10.2.4 User-defined alias>>doc:null||anchor="H10.2.4User-definedalias"]]
108 *** [[10.2.5 References to SDMX artefacts from VTL Rulesets>>doc:null||anchor="H10.2.5ReferencestoSDMXartefactsfromVTLRulesets"]]
109 ** [[10.3 Mapping between SDMX and VTL artefacts>>doc:null||anchor="H10.3MappingbetweenSDMXandVTLartefacts"]]
110 *** [[10.3.1 When the mapping occurs>>doc:null||anchor="H10.3.1Whenthemappingoccurs"]]
111 *** [[10.3.2 General mapping of VTL and SDMX data structures>>doc:null||anchor="H10.3.2GeneralmappingofVTLandSDMXdatastructures"]]
112 *** [[10.3.3 Mapping from SDMX to VTL data structures>>doc:null||anchor="H10.3.3MappingfromSDMXtoVTLdatastructures"]]
113 **** [[10.3.3.1 Basic Mapping >>doc:null||anchor="H10.3.3.1BasicMapping"]]
114 **** [[10.3.3.2 Pivot Mapping>>doc:null||anchor="H10.3.3.2PivotMapping"]]
115 **** [[10.3.3.3 From SDMX DataAttributes to VTL Measures>>doc:null||anchor="H10.3.3.3FromSDMXDataAttributestoVTLMeasures"]]
116 *** [[10.3.4 Mapping from VTL to SDMX data structures>>doc:null||anchor="H10.3.4MappingfromVTLtoSDMXdatastructures"]]
117 **** [[10.3.4.1 Basic Mapping >>doc:null||anchor="H10.3.4.1BasicMapping"]]
118 **** [[10.3.4.2 Unpivot Mapping>>doc:null||anchor="H10.3.4.2UnpivotMapping"]]
119 **** [[10.3.4.3 From VTL Measures to SDMX Data Attributes >>doc:null||anchor="H10.3.4.3FromVTLMeasurestoSDMXDataAttributes"]]
120 *** [[10.3.5 Declaration of the mapping methods between data structures>>doc:null||anchor="H10.3.5Declarationofthemappingmethodsbetweendatastructures"]]
121 *** [[10.3.6 Mapping dataflow subsets to distinct VTL data sets~[25~]>>doc:null||anchor="H10.3.6MappingdataflowsubsetstodistinctVTLdatasets5B255D"]]
122 *** [[10.3.7 Mapping variables and value domains between VTL and SDMX>>doc:null||anchor="H10.3.7MappingvariablesandvaluedomainsbetweenVTLandSDMX"]]
123 ** [[10.4 Mapping between SDMX and VTL Data Types>>doc:null||anchor="H10.4MappingbetweenSDMXandVTLDataTypes"]]
124 *** [[10.4.1 VTL Data types>>doc:null||anchor="H10.4.1VTLDatatypes"]]
125 *** [[10.4.2 VTL basic scalar types and SDMX data types>>doc:null||anchor="H10.4.2VTLbasicscalartypesandSDMXdatatypes"]]
126 *** [[10.4.3 Mapping SDMX data types to VTL basic scalar types>>doc:null||anchor="H10.4.3MappingSDMXdatatypestoVTLbasicscalartypes"]]
127 *** [[10.4.4 Mapping VTL basic scalar types to SDMX data types>>doc:null||anchor="H10.4.4MappingVTLbasicscalartypestoSDMXdatatypes"]]
128 *** [[10.4.5 Null Values>>doc:null||anchor="H10.4.5NullValues"]]
129 *** [[10.4.6 Format of the literals used in VTL transformations>>doc:null||anchor="H10.4.6FormatoftheliteralsusedinVTLtransformations"]]
130 * [[11 Annex I: How to eliminate extra element in the .NET SDMX Web Service>>doc:null||anchor="H11AnnexI:Howtoeliminateextraelementinthe.NETSDMXWebService"]]
131 ** [[11.1 Problem statement>>doc:null||anchor="H11.1Problemstatement"]]
132 ** [[11.2 Solution>>doc:null||anchor="H11.2Solution"]]
133 ** [[11.3 Applying the solution>>doc:null||anchor="H11.3Applyingthesolution"]]
134 )))
135 )))
136 )))
137 )))
138
139 **Revision History**
140
141 (% style="width:954.835px" %)
142 |(% style="width:106px" %)**Revision**|(% style="width:124px" %)**Date**|(% style="width:723px" %)**Contents**
143 |(% style="width:106px" %) |(% style="width:124px" %)April 2011|(% style="width:723px" %)Initial release
144 |(% style="width:106px" %)1.0|(% style="width:124px" %)April 2013|(% style="width:723px" %)Added section 9 - Transforming between versions of SDMX
145 |(% style="width:106px" %)2.0|(% style="width:124px" %)July 2020|(% style="width:723px" %)Added section 10 – Validation and Transformation Language – before the Annex 1.
146
147 = 1 Purpose and Structure =
148
149 == 1.1 Purpose ==
150
151 The intention of this document is to document certain aspects of [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] that are important to understand and will aid implementation decisions. The explanations here supplement the information documented in the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] XML schema and the Information Model.
152
153 == 1.2 Structure ==
154
155 This document is organized into the following major parts:
156
157 A guide to the [[SDMX Information Model>>doc:sdmx:Glossary.SDMX Information Model.WebHome]] relating to [[Data Structure Definitions>>doc:sdmx:Glossary.Data structure definition.WebHome]] and [[Data Sets>>doc:sdmx:Glossary.Data set.WebHome]], statement of differences in functionality supported by the different formats and syntaxes for [[Data Structure Definitions>>doc:sdmx:Glossary.Data structure definition.WebHome]] and [[Data Sets>>doc:sdmx:Glossary.Data set.WebHome]], and best practices for use of [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] formats, including the [[representation>>doc:sdmx:Glossary.Representation.WebHome]] for time period
158
159 A guide to the [[SDMX Information Model>>doc:sdmx:Glossary.SDMX Information Model.WebHome]] relating to [[Metadata Structure Definitions>>doc:sdmx:Glossary.Metadata structure definition.WebHome]], and Metadata Sets
160
161 Other structural [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] of interest: agencies, (% style="color:#e74c3c" %)concept(%%) role. (% style="color:#e74c3c" %)constraint(%%), partial [[code list>>doc:sdmx:Glossary.Code list.WebHome]]
162
163 = 2 General Notes on This Document =
164
165 At this (% style="color:#e74c3c" %)version(%%) of the standards, the term “Key family” is replaced by [[Data Structure Definition>>doc:sdmx:Glossary.Data structure definition.WebHome]] (also known and referred to as [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]]) both in the XML schemas and the Information Model. The term “Key family” is not familiar to many people and its name was taken from the model of [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]] (previously known as GESMES/TS). The more familiar name “[[Data Structure Definition>>doc:sdmx:Glossary.Data structure definition.WebHome]]” which was used in many documents is now also the technical [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] in the [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] and Information Model technical specifications. The term “Key family” is still used in the [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]] specification.
166
167 There has been much work within the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] community on the creation of user guides, tutorials, and other aides to implementation and understanding of the standard. This document is not intended to duplicate the function of these documents, but instead represents a short set of technical notes not generally covered elsewhere.
168
169 = 3 Guide for SDMX Format Standards =
170
171 == 3.1 Introduction ==
172
173 This guide exists to provide information to implementers of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] format standards – [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] and [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]] – that are concerned with data, i.e. [[Data Structure Definitions>>doc:sdmx:Glossary.Data structure definition.WebHome]] and [[Data Sets>>doc:sdmx:Glossary.Data set.WebHome]]. This section is intended to provide information which will help users of [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] understand and implement the standards. It is not normative, and it does not provide any rules for the use of the standards, such as those found in //[[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]]: Schema and Documentation// and //[[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]]: Syntax and Documentation//.
174
175 == 3.2 SDMX Information Model for Format Implementers ==
176
177 === 3.2.1 Introduction ===
178
179 The purpose of this sub-section is to provide an introduction to the [[SDMX-IM>>doc:sdmx:Glossary.SDMX Information Model.WebHome]] relating to [[Data Structure Definitions>>doc:sdmx:Glossary.Data structure definition.WebHome]] and [[Data Sets>>doc:sdmx:Glossary.Data set.WebHome]] for those whose primary interest is in the use of the XML or EDI formats. For those wishing to have a deeper understanding of the Information Model, the full [[SDMX-IM>>doc:sdmx:Glossary.SDMX Information Model.WebHome]] document, and other sections in this guide provide a more in-depth view, along with UML diagrams and supporting explanation. For those who are unfamiliar with DSDs, an appendix to the [[SDMX-IM>>doc:sdmx:Glossary.SDMX Information Model.WebHome]] provides a tutorial which may serve as a useful introduction.
180
181 The [[SDMX-IM>>doc:sdmx:Glossary.SDMX Information Model.WebHome]] is used to describe the basic data and metadata structures used in all of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] data formats. The Information Model concerns itself with statistical data and its [[structural metadata>>doc:sdmx:Glossary.Structural metadata.WebHome]], and that is what is described here. Both [[structural metadata>>doc:sdmx:Glossary.Structural metadata.WebHome]] and data have some additional metadata in common, related to their management and administration. These aspects of the data model are not addressed in this section and covered elsewhere in this guide or in the full [[SDMX-IM>>doc:sdmx:Glossary.SDMX Information Model.WebHome]] document.
182
183 The [[Data Structure Definition>>doc:sdmx:Glossary.Data structure definition.WebHome]] and [[Data Set>>doc:sdmx:Glossary.Data set.WebHome]] parts of the information model are consistent with the GESMES/TS (% style="color:#e74c3c" %)version(%%) 3.0 Data Model (called [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]] in the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] standard), with these exceptions:
184
185 * the “[[sibling group>>doc:sdmx:Glossary.Sibling group.WebHome]]” construct has been generalized to permit any [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]] or [[dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] to be wildcarded, and not just frequency, as in GESMES/TS. It has been renamed a “group” to distinguish it from the “[[sibling group>>doc:sdmx:Glossary.Sibling group.WebHome]]” where only frequency is wildcarded. The set of allowable partial “group” keys must be declared in the [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]], and [[attributes>>doc:sdmx:Glossary.Attribute.WebHome]] may be attached to any of these [[group keys>>doc:sdmx:Glossary.Group key.WebHome]];
186 * furthermore, whilst the “group” has been retained for compatibility with (% style="color:#e74c3c" %)version(%%) 2.0 and with [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]], it has, at (% style="color:#e74c3c" %)version(%%) 2.1, been replaced by the “[[Attribute Relationship>>doc:sdmx:Glossary.Attribute relationship.WebHome]]” definition which is explained later
187 * the section on data [[representation>>doc:sdmx:Glossary.Representation.WebHome]] is now a convention, to support interoperability with EDIFACT-syntax implementations ( see section 3.3.2);
188
189 [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]]-specific data formats are derived from the model, and some supporting features for declaring multiple [[measures>>doc:sdmx:Glossary.Measure.WebHome]] have been added to the [[structural metadata>>doc:sdmx:Glossary.Structural metadata.WebHome]] descriptions Clearly, this is not a coincidence. The GESMES/TS Data Model provides the foundation for the EDIFACT messages in [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]], and also is the starting point for the development of [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]].
190
191 Note that in the descriptions below, text in courier and italicised are the names used in the information model (e.g. //[[DataSet>>doc:sdmx:Glossary.Data set.WebHome]]//).
192
193 == 3.3 SDMX-ML and SDMX-EDI: Comparison of Expressive Capabilities and Function ==
194
195 [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] offers several equivalent formats for describing data and [[structural metadata>>doc:sdmx:Glossary.Structural metadata.WebHome]], optimized for use in different applications. Although all of these formats are derived directly from the SDM-IM, and are thus equivalent, the syntaxes used to express the model place some restrictions on their use. Also, different optimizations provide different capabilities. This section describes these differences, and provides some rules for applications which may need to support more than one [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] format or syntax. This section is constrained to the Data Structure Definitionand the Date Set.
196
197 === 3.3.1 Format Optimizations and Differences ===
198
199 The following section provides a brief overview of the differences between the various [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] formats.
200
201 (% style="color:#e74c3c" %)Version(%%) 2.0 was characterised by 4 data messages, each with a distinct format: Generic, Compact, Cross-Sectional and Utility. Because of the design, data in some formats could not always be related to another format. In (% style="color:#e74c3c" %)version(%%) 2.1, this issue has been addressed by merging some formats and eliminating others. As a result, in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] 2.1 there are just two types of data formats: //GenericData// and //StructureSpecificData// (i.e. specific to one [[Data Structure Definition>>doc:sdmx:Glossary.Data structure definition.WebHome]]).
202
203 Both of these formats are now flexible enough to allow for data to be oriented in series with any [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]] used to disambiguate the observations (as opposed to only time or a cross sectional [[measure>>doc:sdmx:Glossary.Measure.WebHome]] in (% style="color:#e74c3c" %)version(%%) 2.0). The formats have also been expanded to allow for ungrouped observations.
204
205 To allow for applications which only understand time series data, variations of these formats have been introduced in the form of two data messages; //GenericTimeSeriesData// and //StructureSpecificTimeSeriesData//. It is important to note that these variations are built on the same root structure and can be processed in the same manner as the base format so that they do NOT introduce additional processing requirements.
206
207 **//Structure Definition//**
208
209 The [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] Structure Message supports the use of [[annotations>>doc:sdmx:Glossary.Annotation.WebHome]] to the structure, which is not supported by the [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]] syntax.
210
211 The [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] Structure Message allows for the structures on which a [[Data Structure Definition>>doc:sdmx:Glossary.Data structure definition.WebHome]] depends – that is, codelists and (% style="color:#e74c3c" %)concepts(%%) – to be either included in the message or to be referenced by the message containing the [[data structure definition>>doc:sdmx:Glossary.Data structure definition.WebHome]]. XML syntax is designed to leverage URIs and other Internet-based referencing mechanisms, and these are used in the [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] message. This option is not available to those using the [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]] structure message.
212
213 **//Validation//**
214
215 [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]] – as is typical of EDIFACT syntax messages – leaves validation to dedicated applications (“validation” being the checking of syntax, data typing, and adherence of the data message to the structure as described in the structural definition.)
216
217 The [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] Generic Data Message also leaves validation above the XML syntax (% style="color:#e74c3c" %)level(%%) to the application.
218
219 The [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]]-specific messages will allow validation of XML syntax and datatyping to be performed with a generic XML parser, and enforce agreement between the structural definition and the data to a moderate degree with the same tool.
220
221 //Update and Delete Messages and Documentation Messages//
222
223 All [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] data messages allow for both delete messages and messages consisting of only data or only documentation.
224
225 **//Character Encodings//**
226
227 All [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] messages use the UTF-8 encoding, while [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]] uses the ISO 8879-1 character encoding. There is a greater capacity with UTF-8 to express some character sets (see the “APPENDIX: (% style="color:#e74c3c" %)MAP(%%) OF ISO 8859-1 (UNOC) CHARACTER SET (LATIN 1 OR “WESTERN”) in the document “SYNTAX AND DOCUMENTATION (% style="color:#e74c3c" %)VERSION(%%) 2.0”.) Many transformation tools are available which allow XML instances with UTF-8 encodings to be expressed as ISO 8879-1-encoded characters, and to transform UTF-8 into ISO 8879-1. Such tools should be used when transforming [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] messages into [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]] messages and vice-versa.
228
229 **//Data Typing//**
230
231 The XML syntax and EDIFACT syntax have different data-typing mechanisms. The section below provides a set of conventions to be observed when support for messages in both syntaxes is required. For more information on the [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] [[representations>>doc:sdmx:Glossary.Representation.WebHome]] of data, see below.
232
233 === 3.3.2 Data Types ===
234
235 The XML syntax has a very different mechanism for data-typing than the EDIFACT syntax, and this difference may create some difficulties for applications which support both EDIFACT-based and XML-based [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] data formats. This section provides a set of conventions for the expression in data in all formats, to allow for clean interoperability between them.
236
237 It should be noted that this section does not address character encodings – it is assumed that conversion software will include the use of transformations which will (% style="color:#e74c3c" %)map(%%) between the ISO 8879-1 encoding of the [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]] format and the UTF-8 encoding of the [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] formats.
238
239 Note that the following conventions may be followed for ease of interoperation between EDIFACT and XML [[representations>>doc:sdmx:Glossary.Representation.WebHome]] of the data and metadata. For implementations in which no transformation between EDIFACT and XML syntaxes is foreseen, the restrictions below need not apply.
240
241 1. **Identifiers** are:
242 1*. Maximum 18 characters;
243 1*. Any of A..Z (upper case alphabetic), 0..9 (numeric), _ (underscore);
244 1*. The first character is alphabetic.
245 1. **Names** are:
246 1*. Maximum 70 characters.
247 1*. From ISO 8859-1 character set (including accented characters)
248 1. **Descriptions **are:
249 1*. Maximum 350 characters;
250 1*. From ISO 8859-1 character set.
251 1. **Code values** are:
252 1*. Maximum 18 characters;
253 1*. Any of A..Z (upper case alphabetic), 0..9 (numeric), _ (underscore), / (solidus, slash), = (equal sign), - (hyphen);
254
255 However, [[code>>doc:sdmx:Glossary.Code.WebHome]] values providing values to a [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]] must use only the following characters:
256
257 A..Z (upper case alphabetic), 0..9 (numeric), _ (underscore)
258
259 **5. Observation values** are:
260
261 * [[Decimal>>doc:sdmx:Glossary.Decimals.WebHome]] numerics (signed only if they are negative);
262 * The maximum number of significant figures is:
263 * 15 for a positive number
264 * 14 for a positive [[decimal>>doc:sdmx:Glossary.Decimals.WebHome]] or a negative integer
265 * 13 for a negative [[decimal>>doc:sdmx:Glossary.Decimals.WebHome]]
266 * Scientific notation may be used.
267
268 **6. Uncoded statistical concept** text values are:
269
270 * Maximum 1050 characters;
271 * From ISO 8859-1 character set.
272
273 **7. Time series keys**:
274
275 In principle, the maximum permissible length of time [[series keys>>doc:sdmx:Glossary.Series key.WebHome]] used in a data exchange does not need to be restricted. However, for working purposes, an effort is made to limit the maximum length to 35 characters; in this length, also (for SDMXEDI) one (separator) position is included between all successive [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]] values; this means that the maximum length allowed for a pure [[series key>>doc:sdmx:Glossary.Series key.WebHome]] (concatenation of [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]] values) can be less than 35 characters. The separator character is a colon (“:”) by conventional usage.
276
277 == 3.4 SDMX-ML and SDMX-EDI Best Practices ==
278
279 === 3.4.1 Reporting and Dissemination Guidelines ===
280
281 ==== 3.4.1.1 Central Institutions and Their Role in Statistical Data Exchanges ====
282
283 Central institutions are the organisations to which other partner institutions "report" statistics. These statistics are used by central institutions either to compile aggregates and/or they are put together and made available in a uniform manner (e.g. on-line or on a CD-ROM or through file transfers). Therefore, central institutions receive data from other institutions and, usually, they also "disseminate" data to individual and/or institutions for end-use. Within a country, a NSI or a national central bank (NCB) plays, of course, a central institution role as it collects data from other entities and it disseminates statistical information to end users. In [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] the role of central institution is very important: every statistical message is based on underlying structural definitions (statistical (% style="color:#e74c3c" %)concepts(%%), [[code lists>>doc:sdmx:Glossary.Code list.WebHome]], DSDs) which have been devised by a particular agency, usually a central institution. Such an institution plays the role of the reference "structural definitions [[maintenance agency>>doc:sdmx:Glossary.Maintenance agency.WebHome]] for the corresponding messages which are exchanged. Of course, two institutions could exchange data using/referring to structural information devised by a third institution.
284
285 Central institutions can play a double role:
286
287 * collecting and further disseminating statistics;
288 * devising structural definitions for use in data exchanges.
289
290 ==== 3.4.1.2 Defining Data Structure Definitions (DSDs) ====
291
292 The following guidelines are suggested for building a [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]]. However, it is expected that these guidelines will be considered by central institutions when devising new DSDs.
293
294 (% class="wikigeneratedid" id="HDimensions2CAttributesandCodeLists" %)
295 __Dimensions, Attributes and Code Lists__
296
297 **//Avoid [[dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] that are not appropriate for all the series in the [[data structure definition>>doc:sdmx:Glossary.Data structure definition.WebHome]].//** If some [[dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] are not applicable (this is evident from the need to have a [[code>>doc:sdmx:Glossary.Code.WebHome]] in a [[code list>>doc:sdmx:Glossary.Code list.WebHome]] which is marked as “not applicable”, “not relevant” or “total”) for some series then consider moving these series to a new [[data structure definition>>doc:sdmx:Glossary.Data structure definition.WebHome]] in which these [[dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] are dropped from the key structure. This is a judgement call as it is sometimes difficult to achieve this without increasing considerably the number of DSDs.
298
299 **//Devise DSDs with a small number of [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] for public viewing of data.//** A [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] with the number [[dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] in excess 6 or 7 is often difficult for non specialist users to understand. In these cases it is better to have a larger number of DSDs with smaller “cubes” of data, or to eliminate [[dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] and aggregate the data at a higher (% style="color:#e74c3c" %)level(%%). Dissemination of data on the web is a growing use case for the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] standards: the differentiation of observations by dimensionality which are necessary for statisticians and economists are often obscure to public consumers who may not always understand the semantic of the differentiation.
300
301 **//Avoid composite [[dimensions>>doc:sdmx:Glossary.Dimension.WebHome]].//** Each [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]] should correspond to a single characteristic of the data, not to a combination of characteristics.
302
303 **//Consider the inclusion of the following [[attributes>>doc:sdmx:Glossary.Attribute.WebHome]]//**. Once the key structure of a [[data structure definition>>doc:sdmx:Glossary.Data structure definition.WebHome]] has been decided, then the set of (preferably mandatory) [[attributes>>doc:sdmx:Glossary.Attribute.WebHome]] of this [[data structure definition>>doc:sdmx:Glossary.Data structure definition.WebHome]] has to be defined. In general, some statistical (% style="color:#e74c3c" %)concepts(%%) are deemed necessary across all [[Data Structure Definitions>>doc:sdmx:Glossary.Data structure definition.WebHome]] to qualify the contained information. Examples of these are:
304
305 * A descriptive [[title>>doc:sdmx:Glossary.Title.WebHome]] for the series (this is most useful for dissemination of data for viewing e.g. on the web)
306 * Collection (e.g. end of period, averaged or summed over period)
307 * Unit (e.g. [[currency>>doc:sdmx:Glossary.Currency.WebHome]] of denomination)
308 * Unit multiplier (e.g. expressed in millions)
309 * Availability (which institutions can a series become available to)
310 * Decimals (i.e. number of [[decimal>>doc:sdmx:Glossary.Decimals.WebHome]] digits used in numerical observations)
311 * [[Observation Status>>doc:sdmx:Glossary.Observation status.WebHome]] (e.g. estimate, provisional, normal)
312
313 Moreover, additional [[attributes>>doc:sdmx:Glossary.Attribute.WebHome]] may be considered as mandatory when a specific [[data structure definition>>doc:sdmx:Glossary.Data structure definition.WebHome]] is defined.
314
315 **//Avoid creating a new [[code list>>doc:sdmx:Glossary.Code list.WebHome]] where one already exists.//** It is highly recommended that structural definitions and [[code lists>>doc:sdmx:Glossary.Code list.WebHome]] be consistent with internationally agreed standard methodologies, wherever they exist, e.g., System of National Accounts 1993; Balance of Payments Manual, Fifth Edition; Monetary and Financial Statistics Manual; Government Finance Statistics Manual, etc. When setting-up a new data exchange, the following order of priority is suggested when considering the use of [[code lists>>doc:sdmx:Glossary.Code list.WebHome]]:
316
317 * international standard [[code lists>>doc:sdmx:Glossary.Code list.WebHome]];
318 * international [[code lists>>doc:sdmx:Glossary.Code list.WebHome]] supplemented by other international and/or regional institutions;
319 * standardised lists used already by international institutions;
320 * new [[code lists>>doc:sdmx:Glossary.Code list.WebHome]] agreed between two international or regional institutions;
321 * new specific [[code lists>>doc:sdmx:Glossary.Code list.WebHome]].
322
323 The same [[code list>>doc:sdmx:Glossary.Code list.WebHome]] can be used for several statistical (% style="color:#e74c3c" %)concepts(%%), within a [[data structure definition>>doc:sdmx:Glossary.Data structure definition.WebHome]] or across DSDs. Note that [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] has recognised that these classifications are often quite large and the usage of [[codes>>doc:sdmx:Glossary.Code.WebHome]] in any one [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] is only a small extract of the full [[code list>>doc:sdmx:Glossary.Code list.WebHome]]. In this (% style="color:#e74c3c" %)version(%%) of the standard it is possible to exchange and disseminate a **partial [[code list>>doc:sdmx:Glossary.Code list.WebHome]]** which is extracted from the full [[code list>>doc:sdmx:Glossary.Code list.WebHome]] and which supports the [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]] values valid for a particular [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]].
324
325 __Data Structure Definition Structure__
326
327 The following items have to be specified by a structural definitions [[maintenance agency>>doc:sdmx:Glossary.Maintenance agency.WebHome]] when defining a new [[data structure definition>>doc:sdmx:Glossary.Data structure definition.WebHome]]:
328
329 [[Data structure definition>>doc:sdmx:Glossary.Data structure definition.WebHome]] ([[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]]) identification:
330
331 * [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] identifier
332 * [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] name
333
334 A list of metadata (% style="color:#e74c3c" %)concepts(%%) assigned as [[dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] of the [[data structure definition>>doc:sdmx:Glossary.Data structure definition.WebHome]]. For each:
335
336 * (statistical) (% style="color:#e74c3c" %)concept(%%) identifier
337 * ordinal number of the [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]] in the key structure ([[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]] only)
338 * [[code list>>doc:sdmx:Glossary.Code list.WebHome]] identifier (Id, (% style="color:#e74c3c" %)version(%%), [[maintenance agency>>doc:sdmx:Glossary.Maintenance agency.WebHome]]) if the [[representation>>doc:sdmx:Glossary.Representation.WebHome]] is coded
339
340 A list of (statistical) (% style="color:#e74c3c" %)concepts(%%) assigned as [[attributes>>doc:sdmx:Glossary.Attribute.WebHome]] for the [[data structure definition>>doc:sdmx:Glossary.Data structure definition.WebHome]]. For each:
341
342 * (statistical) (% style="color:#e74c3c" %)concept(%%) identifier
343 * [[code list>>doc:sdmx:Glossary.Code list.WebHome]] identifier if the (% style="color:#e74c3c" %)concept(%%) is coded
344 * assignment status: mandatory or conditional
345 * attachment (% style="color:#e74c3c" %)level
346 * maximum text length for the uncoded (% style="color:#e74c3c" %)concepts
347 * maximum [[code>>doc:sdmx:Glossary.Code.WebHome]] length for the coded (% style="color:#e74c3c" %)concepts
348
349 A list of the [[code lists>>doc:sdmx:Glossary.Code list.WebHome]] used in the [[data structure definition>>doc:sdmx:Glossary.Data structure definition.WebHome]]. For each:
350
351 * [[code list>>doc:sdmx:Glossary.Code list.WebHome]] identifier
352 * [[code list>>doc:sdmx:Glossary.Code list.WebHome]] name
353 * [[code>>doc:sdmx:Glossary.Code.WebHome]] values and descriptions
354
355 Definition of [[data flow>>doc:sdmx:Glossary.Dataflow.WebHome]] definitions. Two (or more) partners performing data exchanges in a certain context need to agree on:
356
357 * the list of [[data set>>doc:sdmx:Glossary.Data set.WebHome]] identifiers they will be using;
358 * for each [[data flow>>doc:sdmx:Glossary.Dataflow.WebHome]]:
359 * its content and description
360 * the relevant [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] that defines the structure of the data reported or disseminated according the the [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] definition
361
362 ==== 3.4.1.3 Exchanging Attributes ====
363
364 ===== //3.4.1.3.1 Attributes on series, sibling and data set level // =====
365
366 //Static properties//.
367
368 * Upon creation of a series the sender has to provide to the receiver values for all mandatory [[attributes>>doc:sdmx:Glossary.Attribute.WebHome]]. In case they are available, values for conditional [[attributes>>doc:sdmx:Glossary.Attribute.WebHome]] should also be provided. Whereas initially this information may be provided by means other than [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] or [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]] messages (e.g. paper, telephone) it is expected that partner institutions will be in a position to provide this information in [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] or [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]] format over time.
369 * A centre may agree with its data exchange partners special procedures for authorising the setting of [[attributes>>doc:sdmx:Glossary.Attribute.WebHome]]' initial values.
370 * [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]] values at a [[data set>>doc:sdmx:Glossary.Data set.WebHome]] (% style="color:#e74c3c" %)level(%%) are set and maintained exclusively by the centre administrating the exchanged [[data set>>doc:sdmx:Glossary.Data set.WebHome]].
371
372 //Communication of changes// to the centre.
373
374 * Following the creation of a series, the [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] values do not have to be reported again by senders, as long as they do not change.
375 * Whenever changes in [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] values for a series (or [[sibling group>>doc:sdmx:Glossary.Sibling group.WebHome]]) occur, the reporting institutions should report either all [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] values again (this is the recommended option) or only the [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] values which have changed. This applies both to the mandatory and the conditional [[attributes>>doc:sdmx:Glossary.Attribute.WebHome]]. For example, if a previously reported value for a conditional [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] is no longer valid, this has to be reported to the centre.
376 * A centre may agree with its data exchange partners special procedures for authorising modifications in the [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] values.
377
378 Communication of observation (% style="color:#e74c3c" %)level(%%) [[attributes>>doc:sdmx:Glossary.Attribute.WebHome]] “[[observation status>>doc:sdmx:Glossary.Observation status.WebHome]]”, "observation [[confidentiality>>doc:sdmx:Glossary.Confidentiality.WebHome]]", "observation pre-break".
379
380 * In [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]], the observation (% style="color:#e74c3c" %)level(%%) [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] “[[observation status>>doc:sdmx:Glossary.Observation status.WebHome]]” is part of the fixed syntax of the ARR segment used for observation reporting. Whenever an observation is exchanged, the corresponding [[observation status>>doc:sdmx:Glossary.Observation status.WebHome]] must also be exchanged attached to the observation, regardless of whether it has changed or not since the previous data exchange. This rule also applies to the use of the [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] formats, although the syntax does not necessarily require this.
381 * If the “[[observation status>>doc:sdmx:Glossary.Observation status.WebHome]]” changes and the observation remains unchanged, both [[components>>doc:sdmx:Glossary.Component.WebHome]] would have to be reported.
382 * For [[Data Structure Definitions>>doc:sdmx:Glossary.Data structure definition.WebHome]] having also the observation (% style="color:#e74c3c" %)level(%%) [[attributes>>doc:sdmx:Glossary.Attribute.WebHome]] “observation [[confidentiality>>doc:sdmx:Glossary.Confidentiality.WebHome]]” and "observation pre-break" defined, this rule applies to these [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] as well: if an institution receives from another institution an observation with an [[observation status>>doc:sdmx:Glossary.Observation status.WebHome]] [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] only attached, this means that the associated observation [[confidentiality>>doc:sdmx:Glossary.Confidentiality.WebHome]] and prebreak observation [[attributes>>doc:sdmx:Glossary.Attribute.WebHome]] either never existed or from now they do not have a value for this observation.
383
384 === 3.4.2 Best Practices for Batch Data Exchange ===
385
386 ==== 3.4.2.1 Introduction ====
387
388 Batch data exchange is the exchange and maintenance of entire databases between counterparties. It is an activity that often employs [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]] formats, and might also use the [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]]-specific [[data set>>doc:sdmx:Glossary.Data set.WebHome]]. The following points apply equally to both formats.
389
390 ==== 3.4.2.2 Positioning of the Dimension "Frequency" ====
391
392 The position of the “frequency” [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]] is unambiguously identified in the [[data structure definition>>doc:sdmx:Glossary.Data structure definition.WebHome]]. Moreover, most central institutions devising structural definitions have decided to assign to this [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]] the first position in the key structure. This facilitates the easy identification of this [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]], something that it is necessary to frequency's crucial role in several database systems and in attaching [[attributes>>doc:sdmx:Glossary.Attribute.WebHome]] at the “sibling” group (% style="color:#e74c3c" %)level(%%).
393
394 ==== 3.4.2.3 Identification of Data Structure Definitions (DSDs) ====
395
396 In order to facilitate the easy and immediate recognition of the structural definition [[maintenance agency>>doc:sdmx:Glossary.Maintenance agency.WebHome]] that defined a [[data structure definition>>doc:sdmx:Glossary.Data structure definition.WebHome]], most central institutions devising structural definitions use the first characters of the [[data structure definition>>doc:sdmx:Glossary.Data structure definition.WebHome]] identifiers to identify their institution: e.g. BIS_EER, EUROSTAT_BOP_01, ECB_BOP1, etc.
397
398 ==== 3.4.2.4 Identification of the Data Flows ====
399
400 In order to facilitate the easy and immediate recognition of the institution administrating a [[data flow>>doc:sdmx:Glossary.Dataflow.WebHome]] definitions, many central institutions prefer to use the first characters of the [[data flow>>doc:sdmx:Glossary.Dataflow.WebHome]] definition identifiers to identify their institution: e.g. BIS_EER, ECB_BOP1, ECB_BOP1, etc. Note that in GESMES/TS the [[Data Set>>doc:sdmx:Glossary.Data set.WebHome]] plays the role of the [[data flow>>doc:sdmx:Glossary.Dataflow.WebHome]] definition (see //[[DataSet>>doc:sdmx:Glossary.Data set.WebHome]] //in the [[SDMX-IM>>doc:sdmx:Glossary.SDMX Information Model.WebHome]]//)//.
401
402 The statistical information in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] is broken down into two fundamental parts - [[structural metadata>>doc:sdmx:Glossary.Structural metadata.WebHome]] (comprising the [[Data Structure Definition>>doc:sdmx:Glossary.Data structure definition.WebHome]], and associated (% style="color:#e74c3c" %)Concepts(%%) and [[Code Lists>>doc:sdmx:Glossary.Code list.WebHome]]) - see Framework for Standards -, and observational data (the [[DataSet>>doc:sdmx:Glossary.Data set.WebHome]]). This is an important distinction, with specific terminology associated with each part. Data - which is typically a set of numeric observations at specific points in time - is organized into [[data sets>>doc:sdmx:Glossary.Data set.WebHome]] (//[[DataSet>>doc:sdmx:Glossary.Data set.WebHome]]//) These [[data sets>>doc:sdmx:Glossary.Data set.WebHome]] are structured according to a specific [[Data Structure Definition>>doc:sdmx:Glossary.Data structure definition.WebHome]] (//DataStructureDefinition//) and are described in the [[data flow>>doc:sdmx:Glossary.Dataflow.WebHome]] definition (//DataflowDefinition)// The [[Data Structure Definition>>doc:sdmx:Glossary.Data structure definition.WebHome]] describes the metadata that allows an understanding of what is expressed in the [[data set>>doc:sdmx:Glossary.Data set.WebHome]], whilst the [[data flow>>doc:sdmx:Glossary.Dataflow.WebHome]] definition provides the identifier and other important information (such as the periodicity of reporting) that is common to all of its [[component>>doc:sdmx:Glossary.Component.WebHome]] [[data sets>>doc:sdmx:Glossary.Data set.WebHome]].
403
404 Note that the role of the [[Data Flow>>doc:sdmx:Glossary.Dataflow.WebHome]] (called //DataflowDefintion// in the model) and [[Data Set>>doc:sdmx:Glossary.Data set.WebHome]] is very specific in the model, and the terminology used may not be the same as used in all organisations, and specifically the term [[Data Set>>doc:sdmx:Glossary.Data set.WebHome]] is used differently in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] than in GESMES/TS. Essentially the GESMES/TS term [[Data Set>>doc:sdmx:Glossary.Data set.WebHome]] is, in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]], the [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] Definition" whist the term [[Data Set>>doc:sdmx:Glossary.Data set.WebHome]] in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] is used to describe the "container" for an instance of the data.
405
406 ==== 3.4.2.5 Special Issues ====
407
408 ===== 3.4.2.5.1 "Frequency" related issues =====
409
410 **//Special frequencies.//** The issue of data collected at special (regular or irregular) intervals at a lower than daily frequency (e.g. 24 or 36 or 48 observations per year, on irregular days during the year) is not extensively discussed here. However, for data exchange purposes:
411
412 * such data can be (% style="color:#e74c3c" %)mapped(%%) into a series with daily frequency; this daily series will only hold observations for those days on which the measured event takes place;
413 * if the collection intervals are regular, additional values to the existing frequency [[code list>>doc:sdmx:Glossary.Code list.WebHome]](s) could be added in the future.
414
415 **//Tick data.//** The issue of data collected at irregular intervals at a higher than daily frequency (e.g. tick-by-tick data) is not discussed here either. However, for data exchange purposes, such series can already be exchanged in the [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]] format by using the option to send observations with the associated time stamp.
416
417 = 4 General Notes for Implementers =
418
419 This section discusses a number of topics other than the exchange of [[data sets>>doc:sdmx:Glossary.Data set.WebHome]] in [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] and [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]]. Supported only in [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]], these topics include the use of the [[reference metadata>>doc:sdmx:Glossary.Reference metadata.WebHome]] mechanism in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]], the use of [[Structure Sets>>doc:sdmx:Glossary.Structure set.WebHome]] and [[Reporting Taxonomies>>doc:sdmx:Glossary.Reporting taxonomy.WebHome]], the use of Processes, a discussion of time and data-typing, and some of the conventional mechanisms within the [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] Structure message regarding versioning and external referencing.
420
421 This section does not go into great detail on these topics, but provides a useful overview of these features to assist implementors in further use of the parts of the specification which are relevant to them.
422
423 == 4.1 Representations ==
424
425 There are several different [[representations>>doc:sdmx:Glossary.Representation.WebHome]] in [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]], taken from XML Schemas and common programming languages. The table below describes the various [[representations>>doc:sdmx:Glossary.Representation.WebHome]] which are found in [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]], and their equivalents.
426
427 (% style="width:912.294px" %)
428 |(% style="width:172px" %)**SDMX-ML Data Type**|(% style="width:204px" %)**XML Schema Data Type**|(% style="width:189px" %)**.NET Framework Type**|(% style="width:342px" %)(((
429 **Java Data Type **
430 )))
431 |(% style="width:172px" %)String|(% style="width:204px" %)xsd:string|(% style="width:189px" %)System.String|(% style="width:342px" %)java.lang.String
432 |(% style="width:172px" %)Big Integer|(% style="width:204px" %)xsd:integer|(% style="width:189px" %)System.Decimal|(% style="width:342px" %)java.math.BigInteg er
433 |(% style="width:172px" %)Integer|(% style="width:204px" %)xsd:int|(% style="width:189px" %)System.Int32|(% style="width:342px" %)int
434 |(% style="width:172px" %)Long|(% style="width:204px" %)xsd.long|(% style="width:189px" %)System.Int64|(% style="width:342px" %)long
435 |(% style="width:172px" %)Short|(% style="width:204px" %)xsd:short|(% style="width:189px" %)System.Int16|(% style="width:342px" %)short
436 |(% style="width:172px" %)Decimal|(% style="width:204px" %)xsd:decimal|(% style="width:189px" %)System.Decimal|(% style="width:342px" %)java.math.BigDecim al
437 |(% style="width:172px" %)Float|(% style="width:204px" %)xsd:float|(% style="width:189px" %)System.Single|(% style="width:342px" %)float
438 |(% style="width:172px" %)Double|(% style="width:204px" %)xsd:double|(% style="width:189px" %)System.Double|(% style="width:342px" %)double
439 |(% style="width:172px" %)Boolean|(% style="width:204px" %)xsd:boolean|(% style="width:189px" %)System.Boolean|(% style="width:342px" %)boolean
440 |(% style="width:172px" %)URI|(% style="width:204px" %)xsd:anyURI|(% style="width:189px" %)System.Uri|(% style="width:342px" %)Java.net.URI or java.lang.String
441 |(% style="width:172px" %)DateTime|(% style="width:204px" %)xsd:dateTime|(% style="width:189px" %)System.DateTime|(% style="width:342px" %)javax.xml.datatype .XMLGregorianCalen dar
442 |(% style="width:172px" %)Time|(% style="width:204px" %)xsd:time|(% style="width:189px" %)System.DateTime|(% style="width:342px" %)javax.xml.datatype .XMLGregorianCalen dar
443 |(% style="width:172px" %)GregorianYear|(% style="width:204px" %)xsd:gYear|(% style="width:189px" %)System.DateTime|(% style="width:342px" %)javax.xml.datatype .XMLGregorianCalen dar
444 |(% style="width:172px" %)GregorianMonth|(% style="width:204px" %)xsd:gYearMonth|(% style="width:189px" %)System.DateTime|(% style="width:342px" %)javax.xml.datatype .XMLGregorianCalen dar
445 |(% style="width:172px" %)GregorianDay|(% style="width:204px" %)xsd:date|(% style="width:189px" %)System.DateTime|(% style="width:342px" %)javax.xml.datatype .XMLGregorianCalen dar
446 |(% style="width:172px" %)(((
447 Day, MonthDay, Month
448 )))|(% style="width:204px" %)xsd:g*|(% style="width:189px" %)System.DateTime|(% style="width:342px" %)javax.xml.datatype .XMLGregorianCalen dar
449 |(% style="width:172px" %)Duration|(% style="width:204px" %)xsd:duration |(% style="width:189px" %)System.TimeSpa|(% style="width:342px" %)javax.xml.datatype
450 |(% style="width:172px" %) |(% style="width:204px" %) |(% style="width:189px" %)n|(% style="width:342px" %).Duration
451
452 There are also a number of [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] data types which do not have these direct correspondences, often because they are composite [[representations>>doc:sdmx:Glossary.Representation.WebHome]] or restrictions of a broader data type. For most of these, there are simple types which can be referenced from the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] schemas, for others a derived simple type will be necessary:
453
454 * AlphaNumeric (common:AlphaNumericType, string which only allows A-z and 0-9)
455 * Alpha (common:AlphaType, string which only allows A-z)
456 * Numeric (common:NumericType, string which only allows 0-9, but is not numeric so that is can having leading zeros)
457 * Count (xs:integer, a sequence with an interval of “1”)
458 * InclusiveValueRange (xs:decimal with the minValue and maxValue [[facets>>doc:sdmx:Glossary.Facet.WebHome]] supplying the bounds)
459 * ExclusiveValueRange (xs:decimal with the minValue and maxValue [[facets>>doc:sdmx:Glossary.Facet.WebHome]] supplying the bounds)
460 * Incremental (xs:decimal with a specified interval; the interval is typically enforced outside of the XML validation)
461 * TimeRange (common:TimeRangeType, start DateTime + Duration,)
462 * ObservationalTimePeriod (common: ObservationalTimePeriodType, a union of StandardTimePeriod and TimeRange).
463 * StandardTimePeriod (common: StandardTimePeriodType, a union of BasicTimePeriod and TimeRange).
464 * BasicTimePeriod (common: BasicTimePeriodType, a union of GregorianTimePeriod and DateTime)
465 * GregorianTimePeriod (common:GregorianTimePeriodType, a union of GregorianYear, GregorianMonth, and GregorianDay)
466 * ReportingTimePeriod (common:ReportingTimePeriodType, a union of ReportingYear, ReportingSemester, ReportingTrimester, ReportingQuarter, ReportingMonth, ReportingWeek, and ReportingDay).  ReportingYear (common:ReportingYearType)
467 * ReportingSemester (common:ReportingSemesterType)
468 * ReportingTrimester (common:ReportingTrimesterType)
469 * ReportingQuarter (common:ReportingQuarterType)
470 * ReportingMonth (common:ReportingMonthType)
471 * ReportingWeek (common:ReportingWeekType)
472 * ReportingDay (common:ReportingDayType)
473 * XHTML (common:StructuredText, allows for multi-lingual text content that has XHTML markup)
474 * KeyValues (common:DataKeyType)
475 * IdentifiableReference (types for each identifiable object)
476 * DataSetReference (common:DataSetReferenceType)
477 * AttachmentConstraintReference (common:AttachmentConstraintReferenceType)
478
479 Data types also have a set of [[facets>>doc:sdmx:Glossary.Facet.WebHome]]:
480
481 * isSequence = true | false (indicates a sequentially increasing value)
482 * minLength = positive integer (# of characters/digits)
483 * maxLength = positive integer (# of characters/digits)
484 * startValue = [[decimal>>doc:sdmx:Glossary.Decimals.WebHome]] (for numeric sequence)
485 * endValue = [[decimal>>doc:sdmx:Glossary.Decimals.WebHome]] (for numeric sequence)
486 * interval = [[decimal>>doc:sdmx:Glossary.Decimals.WebHome]] (for numeric sequence)
487 * timeInterval = duration
488 * startTime = BasicTimePeriod (for time range)
489 * endTime = BasicTimePeriod (for time range)
490 * minValue = [[decimal>>doc:sdmx:Glossary.Decimals.WebHome]] (for numeric range)
491 * maxValue = [[decimal>>doc:sdmx:Glossary.Decimals.WebHome]] (for numeric range)
492 * [[decimal>>doc:sdmx:Glossary.Decimals.WebHome]] = Integer (# of digits to right of [[decimal>>doc:sdmx:Glossary.Decimals.WebHome]] point)
493 * pattern = (a regular expression, as per W3C XML Schema)
494 * isMultiLingual = boolean (for specifying text can occur in more than one language)
495
496 Note that [[code lists>>doc:sdmx:Glossary.Code list.WebHome]] may also have textual [[representations>>doc:sdmx:Glossary.Representation.WebHome]] assigned to them, in addition to their enumeration of codes.s
497
498 == 4.2 Time and Time Format ==
499
500 === 4.2.1 Introduction ===
501
502 First, it is important to recognize that most observation times are a period. SDMX specifies precisely how Time is handled.
503
504 The representation of time is broken into a hierarchical collection of representations. A data structure definition can use of any of the representations in the hierarchy as the representation of time. This allows for the time dimension of a particular data structure definition allow for only a subset of the default representation.
505
506 The hierarchy of time formats is as follows (**bold** indicates a category which is made up of multiple formats, //italic// indicates a distinct format):
507
508 * **Observational Time Period**
509 ** **Standard Time Period**
510 *** **Basic Time Period**
511 **** **Gregorian Time Period**
512 **** //Date Time//
513 *** **Reporting Time Period**
514 ** //Time Range//
515
516 The details of these time period categories and of the distinct formats which make them up are detailed in the sections to follow.
517
518 === 4.2.2 Observational Time Period ===
519
520 This is the superset of all time [[representations>>doc:sdmx:Glossary.Representation.WebHome]] in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]]. This allows for time to be expressed as any of the allowable formats.
521
522 === 4.2.3 Standard Time Period ===
523
524 This is the superset of any predefined [[time period>>doc:sdmx:Glossary.Time period.WebHome]] or a distinct point in time. A [[time period>>doc:sdmx:Glossary.Time period.WebHome]] consists of a distinct start and end point. If the start and end of a period are expressed as date instead of a complete date time, then it is implied that the start of the period is the beginning of the start day (i.e. 00:00:00) and the end of the period is the end of the end day (i.e. 23:59:59).
525
526 === 4.2.4 Gregorian Time Period ===
527
528 A Gregorian [[time period>>doc:sdmx:Glossary.Time period.WebHome]] is always represented by a Gregorian year, year-month, or day. These are all based on ISO 8601 dates. The [[representation>>doc:sdmx:Glossary.Representation.WebHome]] in [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] messages and the period covered by each of the Gregorian [[time periods>>doc:sdmx:Glossary.Time period.WebHome]] are as follows:
529
530 **Gregorian Year:**
531 Representation: xs:gYear (YYYY)
532 Period: the start of January 1 to the end of December 31
533
534 **Gregorian Year Month**:
535 Representation: xs:gYearMonth (YYYY-MM)
536 Period: the start of the first day of the month to end of the last day of the month
537
538 **Gregorian Day**:
539 Representation: xs:date (YYYY-MM-DD)
540 Period: the start of the day (00:00:00) to the end of the day (23:59:59)
541
542 === 4.2.5 Date Time ===
543
544 This is used to unambiguously state that a date-time represents an observation at a single point in time. Therefore, if one wants to use [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] for data which is measured at a distinct point in time rather than being reported over a period, the date-time [[representation>>doc:sdmx:Glossary.Representation.WebHome]] can be used.
545
546 [[Representation>>doc:sdmx:Glossary.Representation.WebHome]]: xs:dateTime (YYYY-MM-DDThh:mm:ss)(% contenteditable="false" tabindex="-1" data-macro="startmacro:footnote|-||-|The seconds can be reported fractionally" data-widget="xwiki-macro" class="macro hidden macro-placeholder" %)macro:footnote(% contenteditable="false" tabindex="-1" data-macro="startmacro:footnote|-||-|The seconds can be reported fractionally" data-widget="xwiki-macro" class="macro footnoteRef" id="x_footnote_ref_1" %)^^[[1>>doc:null||anchor="x_footnote_1"]]^^
547
548 === 4.2.6 Standard Reporting Period ===
549
550 Standard reporting periods are periods of time in relation to a reporting year. Each of these standard reporting periods has a duration (based on the ISO 8601 definition) associated with it. The general format of a reporting period is as follows:
551
552 [REPORTING_YEAR]-[PERIOD_INDICATOR][PERIOD_VALUE]
553
554 Where:
555 REPORTING_YEAR represents the reporting year as four digits (YYYY) PERIOD_INDICATOR identifies the type of period which determines the duration of the period
556 PERIOD_VALUE indicates the actual period within the year
557
558 The following section details each of the standard reporting periods defined in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]]:
559
560 **Reporting Year**:
561 Period Indicator: A
562 Period Duration: P1Y (one year)
563 Limit per year: 1
564 Representation: common:ReportingYearType (YYYY-A1, e.g. 2000-A1)
565
566 **Reporting Semester:**
567 Period Indicator: S
568 Period Duration: P6M (six months)
569 Limit per year: 2
570 Representation: common:ReportingSemesterType (YYYY-Ss, e.g. 2000-S2)
571
572 **Reporting Trimester:**
573 Period Indicator: T
574 Period Duration: P4M (four months)
575 Limit per year: 3
576 Representation: common:ReportingTrimesterType (YYYY-Tt, e.g. 2000-T3)
577
578 **Reporting Quarter:**
579 Period Indicator: Q
580 Period Duration: P3M (three months)
581 Limit per year: 4
582 Representation: common:ReportingQuarterType (YYYY-Qq, e.g. 2000-Q4)
583
584 **Reporting Month**:
585 Period Indicator: M
586 Period Duration: P1M (one month)
587 Limit per year: 1
588 Representation: common:ReportingMonthType (YYYY-Mmm, e.g. 2000-M12) Notes: The reporting month is always represented as two digits, therefore 1-9 are 0 padded (e.g. 01). This allows the values to be sorted chronologically using textual sorting methods.
589
590 **Reporting Week**:
591 Period Indicator: W
592 Period Duration: P7D (seven days)
593 Limit per year: 53
594 Representation: common:ReportingWeekType (YYYY-Www, e.g. 2000-W53)
595 Notes: There are either 52 or 53 weeks in a reporting year. This is based on the ISO 8601 definition of a week (Monday - Saturday), where the first week of a reporting year is defined as the week with the first Thursday on or after the reporting year start day.(% contenteditable="false" tabindex="-1" data-macro="startmacro:footnote|-||-|ISO 8601 defines alternative definitions for the first week, all of which produce equivalent results. Any of these definitions could be substituted so long as they are in relation to the reporting year start day." data-widget="xwiki-macro" class="macro hidden macro-placeholder" %)macro:footnote(% contenteditable="false" tabindex="-1" data-macro="startmacro:footnote|-||-|ISO 8601 defines alternative definitions for the first week, all of which produce equivalent results. Any of these definitions could be substituted so long as they are in relation to the reporting year start day." data-widget="xwiki-macro" class="macro footnoteRef" id="x_footnote_ref_2" %)^^[[2>>doc:null||anchor="x_footnote_2"]]^^(%%) The reporting week is always represented as two digits, therefore 1-9 are 0 padded (e.g. 01). This allows the values to be sorted chronologically using textual sorting methods.
596
597 **Reporting Day**:
598 Period Indicator: D
599 Period Duration: P1D (one day)
600 Limit per year: 366
601 Representation: common:ReportingDayType (YYYY-Dddd, e.g. 2000-D366) Notes: There are either 365 or 366 days in a reporting year, depending on whether the reporting year includes leap day (February 29). The reporting day is always represented as three digits, therefore 1-99 are 0 padded (e.g. 001).
602
603 This allows the values to be sorted chronologically using textual sorting methods.
604
605 The meaning of a reporting year is always based on the start day of the year and requires that the reporting year is expressed as the year at the start of the period. This start day is always the same for a reporting year, and is expressed as a day and a month (e.g. July 1). Therefore, the reporting year 2000 with a start day of July 1 begins on July 1, 2000.
606
607 A specialized [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] (reporting year start day) exists for the purpose of communicating the reporting year start day. This [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] has a fixed identifier (REPORTING_YEAR_START_DAY) and a fixed [[representation>>doc:sdmx:Glossary.Representation.WebHome]] (xs:gMonthDay) so that it can always be easily identified and processed in a data message. Although this [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] exists in specialized sub-class, it functions the same as any other [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] outside of its identification and [[representation>>doc:sdmx:Glossary.Representation.WebHome]]. It must takes its identity from a (% style="color:#e74c3c" %)concept(%%) and state its relationship with other [[components>>doc:sdmx:Glossary.Component.WebHome]] of the [[data structure definition>>doc:sdmx:Glossary.Data structure definition.WebHome]]. The ability to state this relationship allows this reporting year start day [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] to exist at the appropriate (% style="color:#e74c3c" %)levels(%%) of a data message. In the absence of this [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]], the reporting year start date is assumed to be January 1; therefore if the reporting year coincides with the calendar year, this [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]] is not necessary.
608
609 Since the duration and the reporting year start day are known for any reporting period, it is possible to relate any reporting period to a distinct calendar period. The actual Gregorian calendar period covered by the reporting period can be computed as follows (based on the standard format of [REPROTING_YEAR][PERIOD_INDICATOR][PERIOD_VALUE] and the reporting year start day as [REPORTING_YEAR_START_DAY]):
610
611 **~1. Determine [REPORTING_YEAR_BASE]:**
612 Combine [REPORTING_YEAR] of the reporting period value (YYYY) with [REPORTING_YEAR_START_DAY] (MM-DD) to get a date (YYYY-MM-DD).
613 This is the [REPORTING_YEAR_START_DATE]
614 **a) If the [PERIOD_INDICATOR] is W:
615 ~1. If [REPORTING_YEAR_START_DATE] is a Friday, Saturday, or Sunday:**
616 Add^^3^^ (P3D, P2D, or P1D respectively) to the [REPORTING_YEAR_START_DATE]. The result is the [REPORTING_YEAR_BASE].
617
618 2. **If [REPORTING_YEAR_START_DATE] is a Monday, Tuesday, Wednesday, or Thursday:**
619 Add^^3^^ (P0D, -P1D, -P2D, or -P3D respectively) to the [REPORTING_YEAR_START_DATE]. The result is the [REPORTING_YEAR_BASE].
620 b) **Else:** 
621 The [REPORTING_YEAR_START_DATE] is the [REPORTING_YEAR_BASE]
622
623 **2. Determine [PERIOD_DURATION]:**
624
625 a) If the [PERIOD_INDICATOR] is A, the [PERIOD_DURATION] is P1Y.
626 b) If the [PERIOD_INDICATOR] is S, the [PERIOD_DURATION] is P6M.
627 c) If the [PERIOD_INDICATOR] is T, the [PERIOD_DURATION] is P4M.
628 d) If the [PERIOD_INDICATOR] is Q, the [PERIOD_DURATION] is P3M.
629 e) If the [PERIOD_INDICATOR] is M, the [PERIOD_DURATION] is P1M.
630 f) If the [PERIOD_INDICATOR] is W, the [PERIOD_DURATION] is P7D.
631 g) If the [PERIOD_INDICATOR] is D, the [PERIOD_DURATION] is P1D.
632
633 **3. Determine [PERIOD_START]:**
634
635 Subtract one from the [PERIOD_VALUE] and multiply this by the [PERIOD_DURATION]. Add[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[3~]^^>>path:#_ftn3]](%%) this to the [REPORTING_YEAR_BASE]. The result is the [PERIOD_START].
636
637 **4. Determine the [PERIOD_END]:**
638 Multiply the [PERIOD_VALUE] by the [PERIOD_DURATION]. Add^^3^^ this to the [REPORTING_YEAR_BASE] add^^3^^ -P1D. The result is the [PERIOD_END].
639
640 For all of these ranges, the bounds include the beginning of the [PERIOD_START] (i.e. 00:00:00) and the end of the [PERIOD_END] (i.e. 23:59:59).
641
642 **Examples:**
643
644 **2010-Q2, REPORTING_YEAR_START_DAY = ~-~-07-01 (July 1)**
645 ~1. [REPORTING_YEAR_START_DATE] = 2010-07-01
646 b) [REPORTING_YEAR_BASE] = 2010-07-01
647 [PERIOD_DURATION] = P3M
648 (2-1) * P3M = P3M
649 2010-07-01 + P3M = 2010-10-01
650 [PERIOD_START] = 2010-10-01
651 4. 2 * P3M = P6M
652 2010-07-01 + P6M = 2010-13-01 = 2011-01-01
653 2011-01-01 + -P1D = 2010-12-31
654 [PERIOD_END] = 2011-12-31
655
656 The actual calendar range covered by 2010-Q2 (assuming the reporting year begins July 1) is 2010-10-01T00:00:00/2010-12-31T23:59:59
657
658 **2011-W36, REPORTING_YEAR_START_DAY = ~-~-07-01 (July 1)**
659 ~1. [REPORTING_YEAR_START_DATE] = 2010-07-01
660 a) 2011-07-01 = Friday
661 2011-07-01 + P3D = 2011-07-04
662 [REPORTING_YEAR_BASE] = 2011-07-04
663 2. [PERIOD_DURATION] = P7D
664 3. (36-1) * P7D = P245D
665 2011-07-04 + P245D = 2012-03-05
666 [PERIOD_START] = 2012-03-05
667 4. 36 * P7D = P252D
668 2011-07-04 + P252D =2012-03-12
669 2012-03-12 + -P1D = 2012-03-11
670 [PERIOD_END] = 2012-03-11
671
672 The actual calendar range covered by 2011-W36 (assuming the reporting year begins July 1) is 2012-03-05T00:00:00/2012-03-11T23:59:59
673
674 === 4.2.7 Distinct Range ===
675
676 In the case that the reporting period does not fit into one of the prescribe periods above, a distinct time range can be used. The value of these ranges is based on the ISO 8601 time interval format of start/duration. Start can be expressed as either an ISO 8601 date or a date-time, and duration is expressed as an ISO 8601 duration. However, the duration can only be postive.
677
678 === 4.2.8 Time Format ===
679
680 In (% style="color:#e74c3c" %)version(%%) 2.0 of [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] there is a recommendation to use the [[time format>>doc:sdmx:Glossary.Time format.WebHome]] [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] to gives additional information on the way time is represented in the message. Following an appraisal of its usefulness this is no longer required. However, it is still possible, if required , to include the [[time format>>doc:sdmx:Glossary.Time format.WebHome]] [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] in [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]].
681
682 (% style="width:716.835px" %)
683 |(% style="width:197px" %)**Code**|(% style="width:517px" %)**Format**
684 |(% style="width:197px" %)**OTP**|(% style="width:517px" %)Observational [[Time Period>>doc:sdmx:Glossary.Time period.WebHome]]: Superset of all [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[time formats>>doc:sdmx:Glossary.Time format.WebHome]] (Gregorian [[Time Period>>doc:sdmx:Glossary.Time period.WebHome]], Reporting [[Time Period>>doc:sdmx:Glossary.Time period.WebHome]], and Time Range)
685 |(% style="width:197px" %)**STP**|(% style="width:517px" %)Standard [[Time Period>>doc:sdmx:Glossary.Time period.WebHome]]: Superset of Gregorian and Reporting [[Time Periods>>doc:sdmx:Glossary.Time period.WebHome]]
686 |(% style="width:197px" %)**GTP**|(% style="width:517px" %)Superset of all Gregorian [[Time Periods>>doc:sdmx:Glossary.Time period.WebHome]] and date-time
687 |(% style="width:197px" %)**RTP**|(% style="width:517px" %)Superset of all Reporting [[Time Periods>>doc:sdmx:Glossary.Time period.WebHome]]
688 |(% style="width:197px" %)**TR**|(% style="width:517px" %)Time Range: Start time and duration (YYYY-MMDD(Thh:mm:ss)?/)
689 |(% style="width:197px" %)**GY**|(% style="width:517px" %)Gregorian Year (YYYY)
690 |(% style="width:197px" %)**GTM**|(% style="width:517px" %)Gregorian Year Month (YYYY-MM)
691 |(% style="width:197px" %)**GD**|(% style="width:517px" %)Gregorian Day (YYYY-MM-DD)
692 |(% style="width:197px" %)**DT**|(% style="width:517px" %)Distinct Point: date-time (YYYY-MM-DDThh:mm:ss)
693 |(% style="width:197px" %)**RY**|(% style="width:517px" %)Reporting Year (YYYY-A1)
694 |(% style="width:197px" %)**RS**|(% style="width:517px" %)Reporting Semester (YYYY-Ss)
695 |(% style="width:197px" %)**RT**|(% style="width:517px" %)Reporting Trimester (YYYY-Tt)
696 |(% style="width:197px" %)**RQ**|(% style="width:517px" %)Reporting Quarter (YYYY-Qq)
697 |(% style="width:197px" %)**RM**|(% style="width:517px" %)Reporting Month (YYYY-Mmm)
698 |(% style="width:197px" %)**[[Code>>doc:sdmx:Glossary.Code.WebHome]]**|(% style="width:517px" %)**Format**
699 |(% style="width:197px" %)**RW**|(% style="width:517px" %)Reporting Week (YYYY-Www)
700 |(% style="width:197px" %)**RD**|(% style="width:517px" %)Reporting Day (YYYY-Dddd)
701
702 **Table 1: SDMX-ML Time Format Codes**
703
704 === 4.2.9 Transformation between SDMX-ML and SDMX-EDI ===
705
706 When converting [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] [[data structure definitions>>doc:sdmx:Glossary.Data structure definition.WebHome]] to [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]] [[data structure definitions>>doc:sdmx:Glossary.Data structure definition.WebHome]], only the identifier of the [[time format>>doc:sdmx:Glossary.Time format.WebHome]] [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] will be retained. The [[representation>>doc:sdmx:Glossary.Representation.WebHome]] of the [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] will be converted from the [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] format to the fixed [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]] [[code list>>doc:sdmx:Glossary.Code list.WebHome]]. If the [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] [[data structure definition>>doc:sdmx:Glossary.Data structure definition.WebHome]] does not define a [[time format>>doc:sdmx:Glossary.Time format.WebHome]] [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]], then one will be automatically created with the identifier "TIME_FORMAT".
707
708 When converting [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] data to [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]], the source [[time format>>doc:sdmx:Glossary.Time format.WebHome]] [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] will be irrelevant. Since the [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] time [[representation>>doc:sdmx:Glossary.Representation.WebHome]] types are not ambiguous, the target [[time format>>doc:sdmx:Glossary.Time format.WebHome]] can be determined from the source time value directly. For example, if the [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] time is 2000-Q2 the [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]] format will always be 608/708 (depending on whether the target series contains one observation or a range of observations).
709
710 When converting a [[data structure definition>>doc:sdmx:Glossary.Data structure definition.WebHome]] originating in [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]], the [[time format>>doc:sdmx:Glossary.Time format.WebHome]] [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] should be ignored, as it serves no purpose in [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]].
711
712 When converting data from [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]] to [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]], the source [[time format>>doc:sdmx:Glossary.Time format.WebHome]] is only necessary to determine the format of the target time value. For example, a source [[time format>>doc:sdmx:Glossary.Time format.WebHome]] of will result in a target time in the format YYYY-Ss whereas a source format of will result in a target time value in the format YYYY-Qq.
713
714 === 4.2.10 Time Zones ===
715
716 In alignment with ISO 8601, [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] allows the specification of a time zone on all [[time periods>>doc:sdmx:Glossary.Time period.WebHome]] and on the reporting year start day. If a time zone is provided on a reporting year start day, then the same time zone (or none) should be reported for each reporting [[time period>>doc:sdmx:Glossary.Time period.WebHome]]. If the reporting year start day and the reporting period time zone differ, the time zone of the reporting period will take precedence. Examples of each format with time zones are as follows (time zone indicated in bold):
717
718 * Time Range (start date): 2006-06-05**-05:00**/P5D
719 * Time Range (start date-time): 2006-06-05T00:00:00**-05:00**/P5D
720 * Gregorian Year: 2006**-05:00**
721 * Gregorian Month: 2006-06**-05:00**
722 * Gregorian Day: 2006-06-05**-05:00**
723 * Distinct Point: 2006-06-05T00:00:00**-05:00**
724 * Reporting Year: 2006-A1**-05:00**
725 * Reporting Semester: 2006-S2**-05:00**
726 * Reporting Trimester: 2006-T2**-05:00**
727 * Reporting Quarter: 2006-Q3**-05:00**
728 * Reporting Month: 2006-M06**-05:00**
729 * Reporting Week: 2006-W23**-05:00**
730 * Reporting Day: 2006-D156**-05:00**
731 * Reporting Year Start Day: 07-01**-05:00**
732
733 According to ISO 8601, a date without a time-zone is considered "local time". [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] assumes that local time is that of the sender of the message. In this (% style="color:#e74c3c" %)version(%%) of [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]], an optional field is added to the sender definition in the header for specifying a time zone. This field has a default value of 'Z' (UTC). This determination of local time applies for all dates in a message.
734
735 === 4.2.11 Representing Time Spans Elsewhere ===
736
737 It has been possible since [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] 2.0 for a [[Component>>doc:sdmx:Glossary.Component.WebHome]] to specify a [[representation>>doc:sdmx:Glossary.Representation.WebHome]] of a time span. Depending on the format of the data message, this resulted in either an element with 2 XML [[attributes>>doc:sdmx:Glossary.Attribute.WebHome]] for holding the start time and the duration or two separate XML [[attributes>>doc:sdmx:Glossary.Attribute.WebHome]] based on the underlying [[Component>>doc:sdmx:Glossary.Component.WebHome]] identifier. For example if REF_PERIOD were given a [[representation>>doc:sdmx:Glossary.Representation.WebHome]] of time span, then in the Compact data format, it would be represented by two XML [[attributes>>doc:sdmx:Glossary.Attribute.WebHome]]; REF_PERIODStartTime (holding the start) and REF_PERIOD (holding the duration). If a new simple type is introduced in the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] schemas that can hold ISO 8601 time intervals, then this will no longer be necessary. What was represented as this:
738
739 <Series REF_PERIODStartTime="2000-01-01T00:00:00" REF_PERIOD="P2M"/>
740
741 can now be represented with this:
742
743 <Series REF_PERIOD="2000-01-01T00:00:00/P2M"/>
744
745 === 4.2.12 Notes on Formats ===
746
747 There is no ambiguity in these formats so that for any given value of time, the [[category>>doc:sdmx:Glossary.Category.WebHome]] of the period (and thus the intended [[time period>>doc:sdmx:Glossary.Time period.WebHome]] range) is always clear. It should also be noted that by utilizing the ISO 8601 format, and a format loosely based on it for the report periods, the values of time can easily be sorted chronologically without additional parsing.
748
749 === 4.2.13 Effect on Time Ranges ===
750
751 All [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] data messages are capable of functioning in a manner similar to [[SDMX-EDI>>doc:sdmx:Glossary.SDMX-EDI.WebHome]] if the [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] at the observation (% style="color:#e74c3c" %)level(%%) is time: the [[time period>>doc:sdmx:Glossary.Time period.WebHome]] for the first observation can be stated and the rest of the observations can omit the time value as it can be derived from the start time and the frequency. Since the frequency can be determined based on the actual format of the time value for everything but distinct points in time and time ranges, this makes is even simpler to process as the interval between time ranges is known directly from the time value.
752
753 === 4.2.14 Time in Query Messages ===
754
755 When querying for time values, the value of a time parameter can be provided as any of the Observational [[Time Period>>doc:sdmx:Glossary.Time period.WebHome]] formats and must be paired with an operator. In addition, an explicit value for the reporting year start day can be provided, or this can be set to "Any". This section will detail how systems processing query messages should interpret these parameters.
756
757 Fundamental to processing a time value parameter in a query message is understanding that all [[time periods>>doc:sdmx:Glossary.Time period.WebHome]] should be handled as a distinct range of time. Since the time parameter in the query is paired with an operator, this is also effectively represents a distinct range of time. Therefore, a system processing the query must simply match the data where the [[time period>>doc:sdmx:Glossary.Time period.WebHome]] for requested parameter is encompassed by the [[time period>>doc:sdmx:Glossary.Time period.WebHome]] resulting from value of the query parameter. The following table details how the operators should be interpreted for any [[time period>>doc:sdmx:Glossary.Time period.WebHome]] provided as a parameter.
758
759 (% style="width:1024.29px" %)
760 |(% style="width:238px" %)**Operator**|(% style="width:782px" %)**Rule**
761 |(% style="width:238px" %)Greater Than|(% style="width:782px" %)Any data after the last moment of the period
762 |(% style="width:238px" %)Less Than|(% style="width:782px" %)Any data before the first moment of the period
763 |(% style="width:238px" %)Greater Than or Equal To|(% style="width:782px" %)(((
764 Any data on or after the first moment of the period
765 )))
766 |(% style="width:238px" %)Less Than or Equal To|(% style="width:782px" %)Any data on or before the last moment of the period
767 |(% style="width:238px" %)Equal To|(% style="width:782px" %)Any data which falls on or after the first moment of the period and before or on the last moment of the period
768
769 Reporting [[Time Periods>>doc:sdmx:Glossary.Time period.WebHome]] as query parameters are handled based on whether the value of the reportingYearStartDay XML [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] is an explicit month and day or "Any":
770
771 If the time parameter provides an explicit month and day value for the reportingYearStartDay XML [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]], then the parameter value is converted to a distinct range and processed as any other [[time period>>doc:sdmx:Glossary.Time period.WebHome]] would be processed.
772
773 If the reportingYeartStartDay XML [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] has a value of "Any", then any data within the bounds of the reporting period for the year is matched, regardless of the actual start day of the reporting year. In addition, data reported against a normal calendar period is matched if it falls within the bounds of the time parameter based on a reporting year start day of January 1. When determining whether another reporting period falls within the bounds of a report period query parameter, one will have to take into account the actual [[time period>>doc:sdmx:Glossary.Time period.WebHome]] to compare weeks and days to higher order report periods. This will be demonstrated in the examples to follow.
774
775 Note that the reportingYearStartDay XML [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] on the time value parameter is only used to qualify a reporting period value for the given time value parameter. The usage of this is different than using the [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] value parameter for the actual reporting year start day [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]]. In the case that the [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] value parameters is used for the reporting year start day data structure [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]], it will be treated as any other [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] value parameter; data will be filtered to that which matches the values specified for the given [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]]. For example, if the [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] value parameter references the reporting year start day [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] and specifies a value of "07-01", then only data which has this [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] with the value "07-01" will be returned. In terms of processing any time value parameters, the value supplied in the [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] value parameter will be irrelevant.
776
777 **Examples:**
778
779 **Gregorian Period**
780 Query Parameter: Greater than 2010
781 Literal Interpretation: Any data where the start period occurs after 2010-1231T23:59:59.
782
783 Example Matches:
784
785 * 2011 or later
786 * 2011-01 or later
787 * 2011-01-01 or later
788 * 2011-01-01/P[Any Duration] or any later start date
789 * 2011-[Any reporting period] (any reporting year start day)
790 * 2010-S2 (reporting year start day ~-~-07-01 or later)
791 * 2010-T3 (reporting year start day ~-~-07-01 or later)
792 * 2010-Q3 or later (reporting year start day ~-~-07-01 or later)
793 * 2010-M07 or later (reporting year start day ~-~-07-01 or later)
794 * 2010-W28 or later (reporting year start day ~-~-07-01 or later)
795 * 2010-D185 or later (reporting year start day ~-~-07-01 or later)
796
797 **Reporting Period with explicit start day**
798
799 Query Parameter: Greater than or equal to 2009-Q3, reporting year start day = "-07-01"
800 Literal Interpretation: Any data where the start period occurs on after 2010-0101T00:00:00 (Note that in this case 2009-Q3 is converted to the explicit date range of 2010-01-01/2010-03-31 because of the reporting year start day value). Example Matches: Same as previous example
801
802 **Reporting Period with "Any" start day**
803 Query Parameter: Greater than or equal to 2010-Q3, reporting year start day = "Any"
804 Literal Interpretation: Any data with a reporting period where the start period is on or after the start period of 2010-Q3 for the same reporting year start day, or and data where the start period is on or after 2010-07-01. Example Matches:
805
806 * 2011 or later
807 * 2010-07 or later
808 * 2010-07-01 or later
809 * 2010-07-01/P[Any Duration] or any later start date
810 * 2011-[Any reporting period] (any reporting year start day)
811 * 2010-S2 (any reporting year start day)
812 * 2010-T3 (any reporting year start day)
813 * 2010-Q3 or later (any reporting year start day)
814 * 2010-M07 or later (any reporting year start day)
815 * 2010-W27 or later (reporting year start day ~-~-01-01)(% contenteditable="false" tabindex="-1" data-macro="startmacro:footnote|-||-|2010-Q3 (with a reporting year start day of -\-01-01) starts on 2010-07-01. This is day 4 of week 26, therefore the first week matched is week 27." data-widget="xwiki-macro" class="macro hidden macro-placeholder" %)macro:footnote(% contenteditable="false" tabindex="-1" data-macro="startmacro:footnote|-||-|2010-Q3 (with a reporting year start day of -\-01-01) starts on 2010-07-01. This is day 4 of week 26, therefore the first week matched is week 27." data-widget="xwiki-macro" class="macro footnoteRef" id="x_footnote_ref_3" %)^^[[3>>doc:null||anchor="x_footnote_3"]]^^(%%)  2010-D182 or later (reporting year start day ~-~-01-01)
816 * 2010-W28 or later (reporting year start day ~-~-07-01)(% contenteditable="false" tabindex="-1" data-macro="startmacro:footnote|-||-|2010-Q3 (with a reporting year start day of -\-07-01) starts on 2011-01-01. This is day 6 of week 27, therefore the first week matched is week 28." data-widget="xwiki-macro" class="macro hidden macro-placeholder" %)macro:footnote(% contenteditable="false" tabindex="-1" data-macro="startmacro:footnote|-||-|2010-Q3 (with a reporting year start day of -\-07-01) starts on 2011-01-01. This is day 6 of week 27, therefore the first week matched is week 28." data-widget="xwiki-macro" class="macro footnoteRef" id="x_footnote_ref_4" %)^^[[4>>doc:null||anchor="x_footnote_4"]]^^
817 * 2010-D185 or later (reporting year start day ~-~-07-01)
818
819 == 4.3 Structural Metadata Querying Best Practices ==
820
821 When querying for [[structural metadata>>doc:sdmx:Glossary.Structural metadata.WebHome]], the ability to state how references should be resolved is quite powerful. However, this mechanism is not always necessary and can create an undue burden on the systems processing the queries if it is not used properly.
822
823 Any [[structural metadata>>doc:sdmx:Glossary.Structural metadata.WebHome]] object which contains a reference to an object can be queried based on that reference. For example, a categorisation references both a [[category>>doc:sdmx:Glossary.Category.WebHome]] and the object is it categorising. As this is the case, one can query for categorisations which categorise a particular object or which categorise against a particular [[category>>doc:sdmx:Glossary.Category.WebHome]] or [[category scheme>>doc:sdmx:Glossary.Category scheme.WebHome]]. This mechanism should be used when the referenced object is known.
824
825 When the referenced object is not known, then the reference resolution mechanism could be used. For example, suppose one wanted to find all [[category schemes>>doc:sdmx:Glossary.Category scheme.WebHome]] and the related categorisations for a given [[maintenance agency>>doc:sdmx:Glossary.Maintenance agency.WebHome]]. In this case, one could query for the [[category scheme>>doc:sdmx:Glossary.Category scheme.WebHome]] by the [[maintenance agency>>doc:sdmx:Glossary.Maintenance agency.WebHome]] and specify that parent and sibling references should be resolved. This would result in the categorisations which reference the [[categories>>doc:sdmx:Glossary.Category.WebHome]] in the matched schemes to be returned, as well as the object which they categorise.
826
827 == 4.4 Versioning and External Referencing ==
828
829 Within the [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] Structure Message, there is a pattern for versioning and external referencing which should be pointed out. The identifiers are qualified by their (% style="color:#e74c3c" %)version(%%) numbers – that is, an object with an Agency of “A”, and ID of “X” and a (% style="color:#e74c3c" %)version(%%) of “1.0” is a different object than one with an Agency of “A’, an ID of “X”, and a (% style="color:#e74c3c" %)version(%%) of “1.1”.
830
831 The production (% style="color:#e74c3c" %)versions(%%) of identifiable objects/resources are assumed to be static – that is, they have their isFinal [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] set to ‘true”. Once in production, and object cannot change in any way, or it must be versioned. For cases where an object is not static, the isFinal [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] must have a value of “false”, but non-final objects should not be used outside of a specific system designed to accommodate them. For most purposes, all objects should be declared final before use in production.
832
833 This mechanism is an “early binding” one – everything with a versioned identity is a known quantity, and will not change. It is worth pointing out that in some cases relationships are essentially one-way references: an illustrative case is that of [[Categories>>doc:sdmx:Glossary.Category.WebHome]]. While a [[Category>>doc:sdmx:Glossary.Category.WebHome]] may be referenced by many [[dataflows>>doc:sdmx:Glossary.Dataflow.WebHome]] and [[metadata flows>>doc:sdmx:Glossary.Metadataflow.WebHome]], the addition of more references from flow objects does not (% style="color:#e74c3c" %)version(%%) the [[Category>>doc:sdmx:Glossary.Category.WebHome]]. This is because the flows are not properties of the [[Categories>>doc:sdmx:Glossary.Category.WebHome]] – they merely make references to it. If the name of a [[Category>>doc:sdmx:Glossary.Category.WebHome]] changed, or its subCategories changed, then versioning would be necessary.
834
835 Versioning operates at the (% style="color:#e74c3c" %)level(%%) of versionable and maintainable objects in the [[SDMX information model>>doc:sdmx:Glossary.SDMX Information Model.WebHome]]. If any of the children of objects at these (% style="color:#e74c3c" %)levels(%%) change, then the objects themselves are versioned.
836
837 One area which is much impacted by this versioning scheme is the ability to reference external objects. With the many dependencies within the various structural objects in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]], it is useful to have a scheme for external referencing. This is done at the (% style="color:#e74c3c" %)level(%%) of maintainable objects (DSDs, [[code lists>>doc:sdmx:Glossary.Code list.WebHome]], [[concept schemes>>doc:sdmx:Glossary.Concept scheme.WebHome]], etc.) In an [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] Structure Message, whenever an “[[isExternalReference>>doc:sdmx:Glossary.isExternalReference.WebHome]]” [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] is set to true, then the application must resolve the address provided in the associated “uri” [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] and use the [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] Structure Message stored at that location for the full definition of the object in question. Alternately, if a registry “urn” [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] has been provided, the registry can be used to supply the full details of the object.
838
839 Because the (% style="color:#e74c3c" %)version(%%) number is part of the identifier for an object, (% style="color:#e74c3c" %)versions(%%) are a necessary part of determining that a given resource is the one which was called for. It should be noted that whenever a (% style="color:#e74c3c" %)version(%%) number is not supplied, it is assumed to be “1.0”. (The “x.x” versioning notation is conventional in practice with [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]], but not required.)
840
841 = 5 Metadata Structure Definition (MSD) =
842
843 == 5.1 Scope ==
844
845 The scope of the [[MSD>>doc:sdmx:Glossary.Metadata structure definition.WebHome]] is enhanced in this (% style="color:#e74c3c" %)version(%%) to better support the types of construct to which metadata can be attached. In particular it is possible to specify an attachment to any key or partial key of a [[data set>>doc:sdmx:Glossary.Data set.WebHome]]. This is particularly useful for web dissemination where metadata may be present for the data, but is not stored with the data but is related to it. For this use case to be supported it is necessary to be able to specify in the [[MSD>>doc:sdmx:Glossary.Metadata structure definition.WebHome]] that metadata is attached to a key or partial key, and the actual key or partial key to be identified in the [[Metadata Set>>doc:sdmx:Glossary.Metadata set.WebHome]].
846
847 In addition to the increase in the scope of objects that can be included in an [[MSD>>doc:sdmx:Glossary.Metadata structure definition.WebHome]], the way the identifier mechanism works in this (% style="color:#e74c3c" %)version(%%), and the terminology used, is much simpler.
848
849 == 5.2 Identification of the Object Type to which the Metadata is to be Attached ==
850
851 The following example shows the structure and naming of the [[MSD>>doc:sdmx:Glossary.Metadata structure definition.WebHome]] [[components>>doc:sdmx:Glossary.Component.WebHome]] for the use case of defining full and partial keys.
852
853 The schematic structure of an [[MSD>>doc:sdmx:Glossary.Metadata structure definition.WebHome]] is shown below.
854
855 (% contenteditable="false" tabindex="-1" %)[[image:1747836776649-282.jpeg||data-widget="image"]]
856
857 **Figure 1: Schematic of the Metadata Structure Definition**
858
859 The [[MSD>>doc:sdmx:Glossary.Metadata structure definition.WebHome]] comprises the specification of the object types to which metadata can be reported in a [[Metadata Set>>doc:sdmx:Glossary.Metadata set.WebHome]] (Metadata Target(s)), and the Report Structure(s) comprising the Metadata [[Attributes>>doc:sdmx:Glossary.Attribute.WebHome]] that identify the (% style="color:#e74c3c" %)Concept(%%) for which metadata may be reported in the [[Metadata Set>>doc:sdmx:Glossary.Metadata set.WebHome]]. Importantly, one Report Structure references the Metadata Target for which it is relevant. One Report Structure can reference many Metadata Target i.e. the same Report Structure can be used for different target objects.
860
861 (% contenteditable="false" tabindex="-1" %)[[image:1747836776655-364.jpeg||data-widget="image"]]
862
863 **Figure 2: Example [[MSD>>doc:sdmx:Glossary.Metadata structure definition.WebHome]] showing Metadata Targets**
864
865 Note that the [[SDMX-ML>>doc:sdmx:Glossary.SDMX-ML.WebHome]] schemas have explicit XML elements for each identifiable object type because identifying, for instance, a Maintainable Object has different properties from an Identifiable Object which must also include the agencyId, (% style="color:#e74c3c" %)version(%%), and id of the Maintainable Object in which it resides.
866
867 == 5.3 Report Structure ==
868
869 An example is shown below.
870
871 (% contenteditable="false" tabindex="-1" %)[[image:1747836776658-510.jpeg||data-widget="image"]]
872
873 **Figure 3: Example MSD showing specification of three Metadata Attributes**
874
875 This example shows the following [[hierarchy>>doc:sdmx:Glossary.Hierarchy.WebHome]] of Metadata [[Attributes>>doc:sdmx:Glossary.Attribute.WebHome]]:
876
877 Source – this is presentational and no metadata is expected to be reported at this (% style="color:#e74c3c" %)level
878
879 * Source Type
880 * Collection Source Name
881
882 == 5.4 Metadata Set ==
883
884 An example of reporting metadata according to the [[MSD>>doc:sdmx:Glossary.Metadata structure definition.WebHome]] described above, is shown below.
885
886 (% contenteditable="false" tabindex="-1" %)[[image:1747836776677-246.jpeg||data-widget="image"]]
887
888 **Figure 4: Example Metadata Set **This example shows:
889
890 1. The reference to the [[MSD>>doc:sdmx:Glossary.Metadata structure definition.WebHome]], Metadata Report, and Metadata Target (MetadataTargetValue)
891 1. The reported metadata [[attributes>>doc:sdmx:Glossary.Attribute.WebHome]] (AttributeValueSet)
892
893 = 6 Maintenance Agencies =
894
895 All [[structural metadata>>doc:sdmx:Glossary.Structural metadata.WebHome]] in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] is owned and maintained by a [[maintenance agency>>doc:sdmx:Glossary.Maintenance agency.WebHome]] (Agency identified by agencyID in the schemas). It is vital to the integrity of the [[structural metadata>>doc:sdmx:Glossary.Structural metadata.WebHome]] that there are no conflicts in agencyID. In order to achieve this [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] adopts the following rules:
896
897 1. Agencies are maintained in an [[Agency Scheme>>doc:sdmx:Glossary.Agency scheme.WebHome]] (which is a sub class of Organisation Scheme)
898 1. The [[maintenance agency>>doc:sdmx:Glossary.Maintenance agency.WebHome]] of the [[Agency Scheme>>doc:sdmx:Glossary.Agency scheme.WebHome]] must also be declared in a (different) [[Agency Scheme>>doc:sdmx:Glossary.Agency scheme.WebHome]].
899 1. The “top-(% style="color:#e74c3c" %)level(%%)” agency is [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] and this [[agency scheme>>doc:sdmx:Glossary.Agency scheme.WebHome]] is maintained by [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]].
900 1. Agencies registered in the top-(% style="color:#e74c3c" %)level(%%) scheme can themselves maintain a single [[Agency Scheme>>doc:sdmx:Glossary.Agency scheme.WebHome]]. [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] is an agency in the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[agency scheme>>doc:sdmx:Glossary.Agency scheme.WebHome]]. Agencies in this scheme can themselves maintain a single [[Agency Scheme>>doc:sdmx:Glossary.Agency scheme.WebHome]] and so on.
901 1. The AgencyScheme cannot be versioned and so take a default (% style="color:#e74c3c" %)version(%%) number of 1.0 and cannot be made “final”.
902 1. There can be only one AgencyScheme maintained by any one Agency. It has a fixed Id of AgencyScheme.
903 1. The format of the agency identifier is agencyId.agencyID etc. The top-(% style="color:#e74c3c" %)level(%%) agency in this identification mechanism is the agency registered in the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[agency scheme>>doc:sdmx:Glossary.Agency scheme.WebHome]]. In other words, [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] is not a part of the hierarchical ID structure for agencies. [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] is, itself, a [[maintenance agency>>doc:sdmx:Glossary.Maintenance agency.WebHome]].
904
905 This supports a hierarchical structure of agencyID.
906
907 An example is shown below.
908
909 (% contenteditable="false" tabindex="-1" %)[[image:1747836776680-229.jpeg||data-widget="image"]]
910
911 **Figure 5: Example of Hierarchic Structure of Agencies**
912
913 Each agency is identified by its full [[hierarchy>>doc:sdmx:Glossary.Hierarchy.WebHome]] excluding [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]].
914
915 The XML representing this structure is shown below.
916
917 (% contenteditable="false" tabindex="-1" %)[[image:1747836776682-757.jpeg||data-widget="image"]]
918
919 **Figure 6: Example Agency Schemes Showing a Hierarchy**
920
921 Example of Structure Definitions:
922
923 (% contenteditable="false" tabindex="-1" %)[[image:1747836776687-934.jpeg||data-widget="image"]]
924
925 **Figure 7: Example Showing Use of Agency Identifiers**
926
927 Each of these [[maintenance agencies>>doc:sdmx:Glossary.Maintenance agency.WebHome]] has an identical Codelist with the Id CL_BOP. However, each is uniquely identified by means of the hierarchic agency structure.
928
929 = 7 Concept Roles =
930
931 == 7.1 Overview ==
932
933 The [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] [[Components>>doc:sdmx:Glossary.Component.WebHome]] of [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] and [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]] can play a specific role in the [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] and it is important to some applications that this role is specified. For instance, the following roles are some examples:
934
935 **Frequency **– in a [[data set>>doc:sdmx:Glossary.Data set.WebHome]] the content of this [[Component>>doc:sdmx:Glossary.Component.WebHome]] contains information on the frequency of the observation values
936 **Geography** - in a [[data set>>doc:sdmx:Glossary.Data set.WebHome]] the content of this [[Component>>doc:sdmx:Glossary.Component.WebHome]] contains information on the geographic location of the observation values
937 **Unit** **of [[Measure>>doc:sdmx:Glossary.Measure.WebHome]]** - in a [[data set>>doc:sdmx:Glossary.Data set.WebHome]] the content of this [[Component>>doc:sdmx:Glossary.Component.WebHome]] contains information on the [[unit of measure>>doc:sdmx:Glossary.Unit of measure.WebHome]] of the observation values
938
939 In order for these roles to be extensible and also to enable user communities to maintain community-specific roles, the roles are maintained in a controlled vocabulary which is implemented in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] as (% style="color:#e74c3c" %)Concepts(%%) in a [[Concept Scheme>>doc:sdmx:Glossary.Concept scheme.WebHome]]. The [[Component>>doc:sdmx:Glossary.Component.WebHome]] optionally references this (% style="color:#e74c3c" %)Concept(%%) if it is required to declare the role explicitly. Note that a [[Component>>doc:sdmx:Glossary.Component.WebHome]] can play more than one role and therefore multiple “role” (% style="color:#e74c3c" %)concepts(%%) can be referenced.
940
941 == 7.2 Information Model ==
942
943 The Information Model for this is shown below:
944
945 (% contenteditable="false" tabindex="-1" %)[[image:1747855024745-946.png||data-widget="image"]]
946
947 **Figure 8: Information Model Extract for Concept Role**
948
949 It is possible to specify zero or more (% style="color:#e74c3c" %)concept(%%) roles for a [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]], [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] and Data [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]] (but not the ReportingYearStartDay). The Time [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]], Primary [[Measure>>doc:sdmx:Glossary.Measure.WebHome]], and the [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]] ReportingYearStartDay have explicitly defined roles and cannot be further specified with additional (% style="color:#e74c3c" %)concept(%%) roles.
950
951 == 7.3 Technical Mechanism ==
952
953 The mechanism for maintain and using (% style="color:#e74c3c" %)concept(%%) roles is as follows:
954
955 1. Any recognized Agency can have a [[concept scheme>>doc:sdmx:Glossary.Concept scheme.WebHome]] that contains (% style="color:#e74c3c" %)concepts(%%) that identify (% style="color:#e74c3c" %)concept(%%) roles. Indeed, from a technical perspective any agency can have more than one of these schemes, though this is not recommended.
956 1. The [[concept scheme>>doc:sdmx:Glossary.Concept scheme.WebHome]] that contains the “role” (% style="color:#e74c3c" %)concepts(%%) can contain (% style="color:#e74c3c" %)concepts(%%) that do not play a role.
957 1. There is no explicit indication on the (% style="color:#e74c3c" %)Concept(%%) whether it is a ‘role” (% style="color:#e74c3c" %)concept(%%).
958 1. Therefore, any (% style="color:#e74c3c" %)concept(%%) in any [[concept scheme>>doc:sdmx:Glossary.Concept scheme.WebHome]] is capable of being a “role” (% style="color:#e74c3c" %)concept(%%).
959 1. It is the responsibility of Agencies to ensure their community knows which (% style="color:#e74c3c" %)concepts(%%) in which [[concept schemes>>doc:sdmx:Glossary.Concept scheme.WebHome]] play a “role” and the significance and interpretation of this role. In other words, such (% style="color:#e74c3c" %)concepts(%%) must be known by applications, there is no technical mechanism that can inform an application on how to process such a “role”.
960 1. If the (% style="color:#e74c3c" %)concept(%%) referenced in the (% style="color:#e74c3c" %)Concept(%%) Identity in a [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] [[component>>doc:sdmx:Glossary.Component.WebHome]] ([[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]], [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]], [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]]) is contained in the [[concept scheme>>doc:sdmx:Glossary.Concept scheme.WebHome]] containing (% style="color:#e74c3c" %)concept(%%) roles then the [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] [[component>>doc:sdmx:Glossary.Component.WebHome]] could play the role implied by the (% style="color:#e74c3c" %)concept(%%), if this is understood by the processing application.
961 1. If the (% style="color:#e74c3c" %)concept(%%) referenced in the (% style="color:#e74c3c" %)Concept(%%) Identity in a [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] [[component>>doc:sdmx:Glossary.Component.WebHome]] ([[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]], [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]], [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]]) is not contained in the [[concept scheme>>doc:sdmx:Glossary.Concept scheme.WebHome]] containing (% style="color:#e74c3c" %)concept(%%) roles, and the [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] [[component>>doc:sdmx:Glossary.Component.WebHome]] is playing a role, then the (% style="color:#e74c3c" %)concept(%%) role is identified by the (% style="color:#e74c3c" %)Concept(%%) Role in the schema.
962
963 == 7.4 SDMX-ML Examples in a DSD ==
964
965 The [[Cross-Domain Concept>>doc:sdmx:Glossary.Cross-domain concept.WebHome]] Scheme maintained by [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] contains (% style="color:#e74c3c" %)concept(%%) role (% style="color:#e74c3c" %)concepts(%%) (FREQ chosen as an example).
966
967 (% contenteditable="false" tabindex="-1" %)[[image:1747855054559-410.png||data-widget="image"]]
968
969 Whether this is a role or not depends upon the application understanding that FREQ in the [[Cross-Domain Concept>>doc:sdmx:Glossary.Cross-domain concept.WebHome]] Scheme is a role of Frequency.
970
971 Using a [[Concept Scheme>>doc:sdmx:Glossary.Concept scheme.WebHome]] that is not the [[Cross-Domain Concept>>doc:sdmx:Glossary.Cross-domain concept.WebHome]] Scheme where it is required to assign a role using the [[Cross-Domain Concept>>doc:sdmx:Glossary.Cross-domain concept.WebHome]] Scheme. Again FREQ is chosen as the example.
972
973 (% contenteditable="false" tabindex="-1" %)[[image:1747855075263-887.png||data-widget="image"]]
974
975 This explicitly states that this [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] is playing a role identified by the FREQ (% style="color:#e74c3c" %)concept(%%) in the [[Cross-Domain Concept>>doc:sdmx:Glossary.Cross-domain concept.WebHome]] Scheme. Again the application needs to understand what FREQ in the [[Cross-Domain Concept>>doc:sdmx:Glossary.Cross-domain concept.WebHome]] Scheme implies in terms of a role.
976
977 This is all that is required for interoperability within a community. The important point is that a community must recognise a specific Agency as having the authority to define (% style="color:#e74c3c" %)concept(%%) roles and to maintain these “role” (% style="color:#e74c3c" %)concepts(%%) in a [[concept scheme>>doc:sdmx:Glossary.Concept scheme.WebHome]] together with documentation on the meaning of the role and any relevant processing implications. This will then ensure there is interoperability between systems that understand the use of these (% style="color:#e74c3c" %)concepts(%%).
978
979 Note that each of the [[Components>>doc:sdmx:Glossary.Component.WebHome]] (Data [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]], Primary [[Measure>>doc:sdmx:Glossary.Measure.WebHome]], [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]], [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]], Time [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]]) has a mandatory identity association ((% style="color:#e74c3c" %)Concept(%%) Identity) and if this (% style="color:#e74c3c" %)Concept(%%) also identifies the role then it is possible to state this by
980
981 == 7.5 SDMX Cross Domain Concept Scheme ==
982
983 All (% style="color:#e74c3c" %)concepts(%%) in the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] Cross Domain [[Concept Scheme>>doc:sdmx:Glossary.Concept scheme.WebHome]] are capable of playing a role and this scheme will contain all of the roles that were allowed at (% style="color:#e74c3c" %)version(%%) 2.0 and will be maintained with new roles that are agreed at the (% style="color:#e74c3c" %)level(%%) of the community using the Cross Domain [[Concept Scheme>>doc:sdmx:Glossary.Concept scheme.WebHome]].
984
985 The table below lists the (% style="color:#e74c3c" %)Concepts(%%) that need to be in this scheme either for compatibility with (% style="color:#e74c3c" %)version(%%) 2.0 or because of requests for additional roles at (% style="color:#e74c3c" %)version(%%) 2.1 which have been accepted.
986
987 Note that each of the [[Components>>doc:sdmx:Glossary.Component.WebHome]] (Data [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]], Primary [[Measure>>doc:sdmx:Glossary.Measure.WebHome]], [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]], [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]], Time [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]]) has a mandatory identity association ((% style="color:#e74c3c" %)Concept(%%) Identity) and if this (% style="color:#e74c3c" %)Concept(%%) also identifies the role then it is possible to state this by means of the isRole [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] (isRole=true) Additional roles can still be specified by means of the +role association to additional (% style="color:#e74c3c" %)Concepts(%%) that identify the role.
988
989 = 8 Constraints =
990
991 == 8.1 Introduction ==
992
993 In this (% style="color:#e74c3c" %)version(%%) of [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] the (% style="color:#e74c3c" %)Constraints(%%) is a [[Maintainable Artefact>>doc:sdmx:Glossary.Maintainable artefact.WebHome]] can be associated to one or more of:
994
995 * Data Structure Definition
996 * [[Metadata Structure Definition>>doc:sdmx:Glossary.Metadata structure definition.WebHome]]
997 * [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]]
998 * [[Metadataflow>>doc:sdmx:Glossary.Metadataflow.WebHome]]
999 * [[Provision Agreement>>doc:sdmx:Glossary.Provision agreement.WebHome]]
1000 * [[Data Provider>>doc:sdmx:Glossary.Data provider.WebHome]] (this is restricted to a [[Release Calendar>>doc:sdmx:Glossary.Release policy - release calendar.WebHome]] (% style="color:#e74c3c" %)Constraint(%%))
1001 * Simple or Queryable Datasources
1002
1003 Note that regardless of the artifact to which the (% style="color:#e74c3c" %)Constraint(%%) is associated, it is constraining the contents of [[code lists>>doc:sdmx:Glossary.Code list.WebHome]] in the [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] to which the constrained object is related. This does not apply, of course, to a [[Data Provider>>doc:sdmx:Glossary.Data provider.WebHome]] as the [[Data Provider>>doc:sdmx:Glossary.Data provider.WebHome]] can be associated, via the [[Provision Agreement>>doc:sdmx:Glossary.Provision agreement.WebHome]], to many DSDs. Hence the reason for the restriction on the type of (% style="color:#e74c3c" %)Constraint(%%) that can be attached to a [[Data Provider>>doc:sdmx:Glossary.Data provider.WebHome]].
1004
1005 == 8.2 Types of Constraint ==
1006
1007 The (% style="color:#e74c3c" %)Constraint(%%) can be of one of two types:
1008
1009 * Content (% style="color:#e74c3c" %)constraint
1010 * Attachable (% style="color:#e74c3c" %)constraint
1011
1012 The attachable (% style="color:#e74c3c" %)constraint(%%) is used to define “cube slices” which identify sub sets of data in terms of [[series keys>>doc:sdmx:Glossary.Series key.WebHome]] or [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]] values. The purpose of this is to enable metadata to be attached to the (% style="color:#e74c3c" %)constraint(%%), and thereby to the cube slices defined in the (% style="color:#e74c3c" %)Constraint(%%). The metadata can be attached via the “[[reference metadata>>doc:sdmx:Glossary.Reference metadata.WebHome]]” mechanism – [[MSD>>doc:sdmx:Glossary.Metadata structure definition.WebHome]] and [[Metadata Set>>doc:sdmx:Glossary.Metadata set.WebHome]] – or via a Group in the [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]]. Below is snippet of the schema for a [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] that shows the constructs that enable the (% style="color:#e74c3c" %)Constraint(%%) to referenced from a Group in a [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]].
1013
1014 (% contenteditable="false" tabindex="-1" %)[[image:1747836776695-806.jpeg||data-widget="image"]]
1015
1016 **Figure 9: Extract from the SDMX-ML Schema showing reference to Attachment Constraint**
1017
1018 For the Content (% style="color:#e74c3c" %)Constraint(%%) specific “inheritance” rules apply and these are detailed below.
1019
1020 == 8.3 Rules for a Content Constraint ==
1021
1022 === 8.3.1 Scope of a Content Constraint ===
1023
1024 A Content (% style="color:#e74c3c" %)Constraint(%%) is used specify the content of a data or metadata source in terms of the [[component>>doc:sdmx:Glossary.Component.WebHome]] values or the keys.
1025
1026 In terms of data the [[components>>doc:sdmx:Glossary.Component.WebHome]] are:
1027
1028 * [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]]
1029 * [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]]
1030 * Time [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]]
1031 * Data [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]]
1032 * Primary [[Measure>>doc:sdmx:Glossary.Measure.WebHome]]
1033
1034 And the keys are the content of the KeyDescriptor – i.e. the [[series keys>>doc:sdmx:Glossary.Series key.WebHome]] composed, for each key, by a value for each [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] and [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]]
1035
1036 In terms of [[reference metadata>>doc:sdmx:Glossary.Reference metadata.WebHome]] the [[components>>doc:sdmx:Glossary.Component.WebHome]] are:
1037
1038 * Target Object which is one of:
1039 ** Key Descriptor Values o [[Data Set>>doc:sdmx:Glossary.Data set.WebHome]] o Report Period
1040 ** IdentifiableObject
1041 * Metadata [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]]
1042
1043 The “key” is therefore the combination of the Target Objects that are defined for the Metadata Target.
1044
1045 For a (% style="color:#e74c3c" %)Constraint(%%) based on a [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] the Content (% style="color:#e74c3c" %)Constraint(%%) can reference one or more of:
1046
1047 * Data Structure Definition
1048 * [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]]
1049 * [[Provision Agreement>>doc:sdmx:Glossary.Provision agreement.WebHome]]
1050
1051 For a (% style="color:#e74c3c" %)Constraint(%%) based on an [[MSD>>doc:sdmx:Glossary.Metadata structure definition.WebHome]] the Content (% style="color:#e74c3c" %)Constraint(%%) can reference one or more of:
1052
1053 * [[Metadata Structure Definition>>doc:sdmx:Glossary.Metadata structure definition.WebHome]]
1054 * [[Metadataflow>>doc:sdmx:Glossary.Metadataflow.WebHome]]
1055 * [[Provision Agreement>>doc:sdmx:Glossary.Provision agreement.WebHome]]
1056
1057 Furthermore, there can be more than one Content (% style="color:#e74c3c" %)Constraint(%%) specified for a specific object e.g. more than one (% style="color:#e74c3c" %)Constraint(%%) for a specific [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]].
1058
1059 In view of the flexibility of (% style="color:#e74c3c" %)constraints(%%) attachment, clear rules on their usage are required. These are elaborated below.
1060
1061 === 8.3.2 Multiple Content Constraints ===
1062
1063 There can be many Content (% style="color:#e74c3c" %)Constraints(%%) for any Constrainable [[Artefact>>doc:sdmx:Glossary.Artefact.WebHome]] (e.g. [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]]), subject to the following restrictions:
1064
1065 ==== 8.3.2.1 Cube Region ====
1066
1067 1. The (% style="color:#e74c3c" %)constraint(%%) can contain multiple [[Member Selections>>doc:sdmx:Glossary.Member selection.WebHome]] (e.g. [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]]) but:
1068 1. A specific [[Member Selection>>doc:sdmx:Glossary.Member selection.WebHome]] (e.g. [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] FREQ) can only be contained in one Content (% style="color:#e74c3c" %)Constraint(%%) for any one attached object (e.g. a specific [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] or specific [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]])
1069
1070 ==== 8.3.2.2 Key Set ====
1071
1072 Key Sets will be processed in the order they appear in the (% style="color:#e74c3c" %)Constraint(%%) and wildcards can be used (e.g. any key position not reference explicitly is deemed to be “all values”). As the Key Sets can be “included” or “excluded” it is recommended that Key Sets with wildcards are declared before KeySets with specific [[series keys>>doc:sdmx:Glossary.Series key.WebHome]]. This will minimize the risk that keys are inadvertently included or excluded.
1073
1074 === 8.3.3 Inheritance of a Content Constraint ===
1075
1076 ==== 8.3.3.1 Attachment levels of a Content Constraint ====
1077
1078 There are three (% style="color:#e74c3c" %)levels(%%) of (% style="color:#e74c3c" %)constraint(%%) attachment for which these inheritance rules apply:
1079
1080 * [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]]/[[MSD>>doc:sdmx:Glossary.Metadata structure definition.WebHome]] – top (% style="color:#e74c3c" %)level
1081 ** [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]]/[[Metadataflow>>doc:sdmx:Glossary.Metadataflow.WebHome]] – second (% style="color:#e74c3c" %)level
1082 *** [[Provision Agreement>>doc:sdmx:Glossary.Provision agreement.WebHome]] – third (% style="color:#e74c3c" %)level
1083
1084 Note that these rules do not apply to the Simple Datasoucre or Queryable Datasource: the Content (% style="color:#e74c3c" %)Constraint(%%)(s) attached to these [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] are resolved for this [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] only and do not take into account (% style="color:#e74c3c" %)Constraints(%%) attached to other [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] (e.g. [[Provision Agreement>>doc:sdmx:Glossary.Provision agreement.WebHome]]. [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]], [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]]).
1085
1086 It is not necessary for a Content (% style="color:#e74c3c" %)Constraint(%%) to be attached to higher (% style="color:#e74c3c" %)level(%%) artifact. e.g. it is valid to have a Content (% style="color:#e74c3c" %)Constraint(%%) for a [[Provision Agreement>>doc:sdmx:Glossary.Provision agreement.WebHome]] where there are no (% style="color:#e74c3c" %)constraints(%%) attached the relevant [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] or [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]].
1087
1088 ==== 8.3.3.2 Cascade rules for processing Constraints ====
1089
1090 The processing of the (% style="color:#e74c3c" %)constraints(%%) on either [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]]/[[Metadataflow>>doc:sdmx:Glossary.Metadataflow.WebHome]] or [[Provision Agreement>>doc:sdmx:Glossary.Provision agreement.WebHome]] must take into account the (% style="color:#e74c3c" %)constraints(%%) declared at higher (% style="color:#e74c3c" %)levels(%%). The rules for the lower (% style="color:#e74c3c" %)level(%%) (% style="color:#e74c3c" %)constraints(%%) (attached to [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]]/ [[Metadataflow>>doc:sdmx:Glossary.Metadataflow.WebHome]] and [[Provision Agreement>>doc:sdmx:Glossary.Provision agreement.WebHome]]) are detailed below.
1091
1092 Note that there can be a situation where a (% style="color:#e74c3c" %)constraint(%%) is specified at a lower (% style="color:#e74c3c" %)level(%%) before a (% style="color:#e74c3c" %)constraint(%%) is specified at a higher (% style="color:#e74c3c" %)level(%%). Therefore, it is possible that a higher (% style="color:#e74c3c" %)level(%%) (% style="color:#e74c3c" %)constraint(%%) makes a lower (% style="color:#e74c3c" %)level(%%) (% style="color:#e74c3c" %)constraint(%%) invalid. [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] makes no rules on how such a conflict should be handled when processing the (% style="color:#e74c3c" %)constraint(%%) for attachment. However, the cascade rules on evaluating (% style="color:#e74c3c" %)constraints(%%) for usage are clear - the higher (% style="color:#e74c3c" %)level(%%) (% style="color:#e74c3c" %)constraint(%%) takes precedence in any conflicts that result in a less restrictive specification at the lower (% style="color:#e74c3c" %)level(%%).
1093
1094 ==== 8.3.3.3 Cube Region ====
1095
1096 1. It is not necessary to have a (% style="color:#e74c3c" %)constraint(%%) on the higher (% style="color:#e74c3c" %)level(%%) artifact (e.g. [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] referenced by the [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]]) but if there is such a (% style="color:#e74c3c" %)constraint(%%) at the higher (% style="color:#e74c3c" %)level(%%)(s) then:
1097 a. The lower (% style="color:#e74c3c" %)level(%%) (% style="color:#e74c3c" %)constraint(%%) cannot be less restrictive than the (% style="color:#e74c3c" %)constraint(%%) specified for the same [[Member Selection>>doc:sdmx:Glossary.Member selection.WebHome]] (e.g. [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]]) at the next higher (% style="color:#e74c3c" %)level(%%) which (% style="color:#e74c3c" %)constraints(%%) that [[Member Selection>>doc:sdmx:Glossary.Member selection.WebHome]] (e.g. if the [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] FREQ is constrained to A, Q in a [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] then the (% style="color:#e74c3c" %)constraint(%%) at the [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] or [[Provision Agreement>>doc:sdmx:Glossary.Provision agreement.WebHome]] cannot be A, Q, M or even just M – it can only further constrain A,Q).
1098 b. The (% style="color:#e74c3c" %)constraint(%%) at the lower (% style="color:#e74c3c" %)level(%%) for any one [[Member Selection>>doc:sdmx:Glossary.Member selection.WebHome]] further constrains the content for the same [[Member Selection>>doc:sdmx:Glossary.Member selection.WebHome]] at the higher (% style="color:#e74c3c" %)level(%%)(s).
1099 1. Any [[Member Selection>>doc:sdmx:Glossary.Member selection.WebHome]] which is not referenced in a Content (% style="color:#e74c3c" %)Constraint(%%) is deemed to be constrained according to the Content (% style="color:#e74c3c" %)Constraint(%%) specified at the next higher (% style="color:#e74c3c" %)level(%%) which (% style="color:#e74c3c" %)constraints(%%) that [[Member Selection>>doc:sdmx:Glossary.Member selection.WebHome]].
1100 1. If there is a conflict when resolving the (% style="color:#e74c3c" %)constraint(%%) in terms of a lower-(% style="color:#e74c3c" %)level(%%) (% style="color:#e74c3c" %)constraint(%%) being less restrictive than a higher-(% style="color:#e74c3c" %)level(%%) (% style="color:#e74c3c" %)constraint(%%) then the (% style="color:#e74c3c" %)constraint(%%) at the higher-(% style="color:#e74c3c" %)level(%%) is used.
1101
1102 Note that it is possible for a Content (% style="color:#e74c3c" %)Constraint(%%) at a higher (% style="color:#e74c3c" %)level(%%) to constrain, say, four [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] in a single (% style="color:#e74c3c" %)constraint(%%), and a Content (% style="color:#e74c3c" %)Constraint(%%) at a lower (% style="color:#e74c3c" %)level(%%) to constrain the same four in two, three, or four Content (% style="color:#e74c3c" %)Constraints(%%).
1103
1104 ==== 8.3.3.4 Key Set ====
1105
1106 1. It is not necessary to have a (% style="color:#e74c3c" %)constraint(%%) on the higher (% style="color:#e74c3c" %)level(%%) [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] (e.g. [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] referenced by the [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]]) but if there is such a (% style="color:#e74c3c" %)constraint(%%) at the higher (% style="color:#e74c3c" %)level(%%)(s) then:
1107 a. The lower (% style="color:#e74c3c" %)level(%%) (% style="color:#e74c3c" %)constraint(%%) cannot be less restrictive than the (% style="color:#e74c3c" %)constraint(%%) specified at the higher (% style="color:#e74c3c" %)level(%%).
1108 b. The (% style="color:#e74c3c" %)constraint(%%) at the lower (% style="color:#e74c3c" %)level(%%) for any one [[Member Selection>>doc:sdmx:Glossary.Member selection.WebHome]] further constrains the keys specified at the higher (% style="color:#e74c3c" %)level(%%)(s).
1109 1. Any [[Member Selection>>doc:sdmx:Glossary.Member selection.WebHome]] which is not referenced in a Content (% style="color:#e74c3c" %)Constraint(%%) is deemed to be constrained according to the Content (% style="color:#e74c3c" %)Constraint(%%) specified at the next higher (% style="color:#e74c3c" %)level(%%) which (% style="color:#e74c3c" %)constraints(%%) that [[Member Selection>>doc:sdmx:Glossary.Member selection.WebHome]].
1110 1. If there is a conflict when resolving the keys in the (% style="color:#e74c3c" %)constraint(%%) at two (% style="color:#e74c3c" %)levels(%%), in terms of a lower-(% style="color:#e74c3c" %)level(%%) (% style="color:#e74c3c" %)constraint(%%) being less restrictive than a higher-(% style="color:#e74c3c" %)level(%%) (% style="color:#e74c3c" %)constraint(%%), then the offending keys specified at the lower (% style="color:#e74c3c" %)level(%%) are not deemed part of the (% style="color:#e74c3c" %)constraint(%%).
1111
1112 Note that a Key in a Key Set can have wildcarded [[Components>>doc:sdmx:Glossary.Component.WebHome]]. For instance the (% style="color:#e74c3c" %)constraint(%%) may simply constrain the [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] FREQ to “A”, and all keys where the FREQ=A are therefore valid.
1113
1114 The following logic explains how the inheritance mechanism works. Note that this is conceptual logic and actual systems may differ in the way this is implemented.
1115
1116 1. Determine all possible keys that are valid at the higher (% style="color:#e74c3c" %)level(%%).
1117 1. These keys are deemed to be inherited by the lower (% style="color:#e74c3c" %)level(%%) constrained object, subject to the (% style="color:#e74c3c" %)constraints(%%) specified at the lower (% style="color:#e74c3c" %)level(%%).
1118 1. Determine all possible keys that are possible using the (% style="color:#e74c3c" %)constraints(%%) specified at the lower (% style="color:#e74c3c" %)level(%%).
1119 1. At the lower (% style="color:#e74c3c" %)level(%%) inherit all keys that match with the higher (% style="color:#e74c3c" %)level(%%) (% style="color:#e74c3c" %)constraint(%%).
1120 1. If there are keys in the lower (% style="color:#e74c3c" %)level(%%) (% style="color:#e74c3c" %)constraint(%%) that are not inherited then the key is invalid (i.e. it is less restrictive).
1121
1122 === 8.3.4 Constraints Examples ===
1123
1124 The following scenario is used.
1125
1126 __DSD__
1127
1128 This contains the following [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]]:
1129
1130 * GEO – Geography
1131 * SEX – Sex
1132 * [[AGE>>doc:sdmx:Glossary.Age.WebHome]] – [[Age>>doc:sdmx:Glossary.Age.WebHome]]
1133 * CAS – Current Activity Status
1134
1135 In the [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] common [[code lists>>doc:sdmx:Glossary.Code list.WebHome]] are used and the requirement is to restrict these at various (% style="color:#e74c3c" %)levels(%%) to specify the actual [[code>>doc:sdmx:Glossary.Code.WebHome]] that are valid for the object to which the Content (% style="color:#e74c3c" %)Constraint(%%) is attached.
1136
1137 (% contenteditable="false" tabindex="-1" %)[[image:1747855493531-357.png||data-widget="image"]]
1138
1139 **Figure 10: Example Scenario for Constraints**
1140
1141 (% style="color:#e74c3c" %)Constraints(%%) are declared as follows:
1142
1143 (% contenteditable="false" tabindex="-1" %)[[image:1747855462293-368.png||data-widget="image"]]
1144
1145 **Figure 11: Example Content Constraints**
1146
1147 **Notes:**
1148
1149 1. [[AGE>>doc:sdmx:Glossary.Age.WebHome]] is constrained for the [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] and is further restricted for the [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] CENSUS_CUBE1.
1150 1. The same (% style="color:#e74c3c" %)Constraint(%%) applies to both Provision Agreements.
1151
1152 The cascade rules elaborated above result as follows:
1153
1154 __DSD__
1155
1156 ~1. Constrained by eliminating [[code>>doc:sdmx:Glossary.Code.WebHome]] 001 from the [[code list>>doc:sdmx:Glossary.Code list.WebHome]] for the [[AGE>>doc:sdmx:Glossary.Age.WebHome]] [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]].
1157
1158 __Dataflow CENSUS_CUBE1__
1159
1160 1. Constrained by restricting the [[code list>>doc:sdmx:Glossary.Code list.WebHome]] for the [[AGE>>doc:sdmx:Glossary.Age.WebHome]] [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] to [[codes>>doc:sdmx:Glossary.Code.WebHome]] 002 and 003(note that this is a more restrictive (% style="color:#e74c3c" %)constraint(%%) than that declared for the [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] which specifies all [[codes>>doc:sdmx:Glossary.Code.WebHome]] except [[code>>doc:sdmx:Glossary.Code.WebHome]] 001).
1161 1. Restricts the CAS [[codes>>doc:sdmx:Glossary.Code.WebHome]] to 003 and 004.
1162
1163 __Dataflow CENSUS_CUBE2__
1164
1165 1. Restricts the [[code list>>doc:sdmx:Glossary.Code list.WebHome]] for the CAS [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] to [[codes>>doc:sdmx:Glossary.Code.WebHome]] TOT and NAP.
1166 1. Inherits the [[AGE>>doc:sdmx:Glossary.Age.WebHome]] (% style="color:#e74c3c" %)constraint(%%) applied at the (% style="color:#e74c3c" %)level(%%) of the [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]].
1167
1168 __Provision Agreements CENSUS_CUBE1_IT__
1169
1170 1. Restricts the [[codes>>doc:sdmx:Glossary.Code.WebHome]] for the GEO [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] to IT and its children.
1171 1. Inherits the (% style="color:#e74c3c" %)constraints(%%) from [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] CENSUS_CUBE1 for the [[AGE>>doc:sdmx:Glossary.Age.WebHome]] and CAS [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]].
1172
1173 __Provision Agreements CENSUS_CUBE2_IT__
1174
1175 1. Restricts the [[codes>>doc:sdmx:Glossary.Code.WebHome]] for the GEO [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] to IT and its children.
1176 1. Inherits the (% style="color:#e74c3c" %)constraints(%%) from [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] CENSUS_CUBE2 for the CAS [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]].
1177 1. Inherits the [[AGE>>doc:sdmx:Glossary.Age.WebHome]] (% style="color:#e74c3c" %)constraint(%%) applied at the (% style="color:#e74c3c" %)level(%%) of the [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]].
1178
1179 The (% style="color:#e74c3c" %)constraints(%%) are defined as follows:
1180
1181 __DSD Constraint__
1182
1183 (% contenteditable="false" tabindex="-1" %)[[image:1747836776698-720.jpeg||data-widget="image"]]
1184
1185 __[[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] (% style="color:#e74c3c" %)Constraints(%%)__
1186
1187 (% contenteditable="false" tabindex="-1" %)[[image:1747836776701-360.jpeg||data-widget="image"]]
1188
1189 (% contenteditable="false" tabindex="-1" %)[[image:1747836776707-834.jpeg||data-widget="image"]]
1190
1191 __Provision Agreement Constraint__
1192
1193 (% contenteditable="false" tabindex="-1" %)[[image:1747836776710-262.jpeg||data-widget="image"]]
1194
1195 = 9 Transforming between versions of SDMX =
1196
1197 == 9.1 Scope ==
1198
1199 The scope of this section is to define both best practices and mandatory behaviour for specific aspects of transformation between different formats of [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]].
1200
1201 == 9.2 Groups and Dimension Groups ==
1202
1203 === 9.2.1 Issue ===
1204
1205 (% style="color:#e74c3c" %)Version(%%) 2.1 introduces a more granular mechanism for specifying the relationship between a Data [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]] and the [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] to which the [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] applies. The technical construct for this is the [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] Group. This [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] Group has no direct equivalent in (% style="color:#e74c3c" %)versions(%%) 2.0 and 1.0 and so the application transforming data from a (% style="color:#e74c3c" %)version(%%) 2.1 [[data set>>doc:sdmx:Glossary.Data set.WebHome]] to a (% style="color:#e74c3c" %)version(%%) 2.0 or (% style="color:#e74c3c" %)version(%%) 1.0 [[data set>>doc:sdmx:Glossary.Data set.WebHome]] must decide to which construct the [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] value, whose [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]] is declared in a [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] Group, should be attached. The closest construct is the “Series” [[attachment level>>doc:sdmx:Glossary.Attachment level.WebHome]] and in many cases this is the correct construct to use.
1206
1207 However, there is one case where the [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] MUST be attached to a Group in the (% style="color:#e74c3c" %)version(%%) 2.0 and 1.0 message. The conditions of this case are:
1208
1209 1. A Group is defined in the [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] with exactly the same [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] as a [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] Group in the same [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]].
1210 1. The [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]] is defined in the [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] with an [[Attribute Relationship>>doc:sdmx:Glossary.Attribute relationship.WebHome]] to the [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] Group. This [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] is NOT defined as having an [[Attribute Relationship>>doc:sdmx:Glossary.Attribute relationship.WebHome]] to the Group.
1211
1212 === 9.2.2 Structural Metadata ===
1213
1214 If the conditions defined in 9.2.1are true then on conversion to a (% style="color:#e74c3c" %)version(%%) 2.0 or 1.0 [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] (Key Family) the [[Component>>doc:sdmx:Glossary.Component.WebHome]]/[[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]].attachmentLevel must be set to “Group” and the [[Component>>doc:sdmx:Glossary.Component.WebHome]]/[[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]]/AttachmentGroup” is used to identify the Group. Note that under rule(1) in 1.2.1 this group will have been defined in the V 2.1 [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] and so will be present in the V 2.0 transformation.
1215
1216 === 9.2.3 Data ===
1217
1218 If the conditions defined in 9.2.1are true then, on conversion from a 2.1 [[data set>>doc:sdmx:Glossary.Data set.WebHome]] to a 2.0 or 1.0 [[dataset>>doc:sdmx:Glossary.Data set.WebHome]] the [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] value will be placed in the relevant . If these conditions are not true then the [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] value will be placed in the .
1219
1220 === 9.2.4 Compact Schema ===
1221
1222 If the conditions defined in 9.2.1are true then the Compact Schema must be generated with the Group present and the [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]](s) present in that group definition.
1223
1224 = 10 Validation and Transformation Language (VTL) =
1225
1226 == 10.1 Introduction ==
1227
1228 The [[Validation and Transformation Language>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] ([[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]]) supports the definition of Transformations, which are algorithms to calculate new data starting from already existing ones[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[4~]^^>>path:#_ftn4]](%%). The purpose of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] in the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] context is to enable the:
1229
1230 * definition of validation and transformation algorithms, in order to specify how to calculate new data from existing ones;
1231 * exchange of the definition of [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] algorithms, also together the definition of the data structures of the involved data (for example, exchange the data structures of a reporting framework together with the validation rules to be applied, exchange the input and output data structures of a calculation task together with the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Transformations describing the calculation algorithms);
1232 * compilation and execution of [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] algorithms, either interpreting the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] transformations or translating them in whatever other computer language is deemed as appropriate.
1233
1234 It is important to note that the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] has its own information model (IM), derived from the Generic Statistical Information Model (GSIM) and described in the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] User Guide. The [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] IM is designed to be compatible with more standards, like [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]], DDI (Data Documentation Initiative) and GSIM, and includes the model [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] that can be manipulated (inputs and/or outputs of transformations, e.g. “[[Data Set>>doc:sdmx:Glossary.Data set.WebHome]]”, “Data Structure”) and the model [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] that allow the definition of the transformation algorithms (e.g. “Transformation”, “Transformation Scheme”).
1235
1236 The [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] language can be applied to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] by (% style="color:#e74c3c" %)mapping(%%) the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] IM model [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] to the model [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] that [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] can manipulate. Thus, the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] can be used in [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] as inputs and/or outputs of transformations. It is important to be aware that the [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] do not always have the same names in the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] and [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] IMs, nor do they always have the same meaning. The more evident example is given by the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Dataset>>doc:sdmx:Glossary.Data set.WebHome]] and the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] “[[Data Set>>doc:sdmx:Glossary.Data set.WebHome]]”, which do not correspond one another: as a matter of fact, the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] “[[Data Set>>doc:sdmx:Glossary.Data set.WebHome]]” (% style="color:#e74c3c" %)maps(%%) to the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] “[[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]]”, while the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] “[[Dataset>>doc:sdmx:Glossary.Data set.WebHome]]” has no explicit (% style="color:#e74c3c" %)mapping(%%) to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] (such an abstraction is not needed in the definition of [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] transformations). A [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] “[[Dataset>>doc:sdmx:Glossary.Data set.WebHome]]”, however, is an instance of a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] “[[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]]” and can be the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] on which the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] transformations are executed (i.e., the transformations are defined on [[Dataflows>>doc:sdmx:Glossary.Dataflow.WebHome]] and are applied to [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] instances that can be Datasets).
1237
1238 The [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] programs (Transformation Schemes) are represented in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] through the TransformationScheme maintainable class which is composed of Transformation ([[nameable artefact>>doc:sdmx:Glossary.Nameable artefact.WebHome]]). Each Transformation assigns the outcome of the evaluation of a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] expression to a result.
1239
1240 This section does not explain the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] language or any of the content published in the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] guides. Rather, this is a description of how the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] can be used in the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] context and applied to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]].
1241
1242 == 10.2 References to SDMX artefacts from VTL statements ==
1243
1244 === 10.2.1 Introduction ===
1245
1246 The [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] can manipulate [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] (or objects) by referencing them through pre-defined conventional names (aliases).
1247
1248 The alias of a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] can be its URN (Universal Resource Name), an abbreviation of its URN or another user-defined name.
1249
1250 In any case, the aliases used in the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] transformations have to be (% style="color:#e74c3c" %)mapped(%%) to the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] through the VtlMappingScheme and VtlMapping classes (see the section of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] IM relevant to the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]]). A VtlMapping allows specifying the aliases to be used in the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] transformations, rulesets[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[5~]^^>>path:#_ftn5]](%%) or user defined operators[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[6~]^^>>path:#_ftn6]](%%) to reference [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]]. A VtlMappingScheme is a container for zero or more VtlMapping.
1251
1252 The correspondence between an alias and a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] must be one-to-one, meaning that a generic alias identifies one and just one [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] while a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] is identified by one and just one alias. In other words, within a VtlMappingScheme an [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] can have just one alias and different [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] cannot have the same alias.
1253
1254 The references through the URN and the abbreviated URN are described in the following paragraphs.
1255
1256 === 10.2.2 References through the URN ===
1257
1258 This approach has the advantage that in the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[code>>doc:sdmx:Glossary.Code.WebHome]] the URN of the referenced [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] is directly intelligible by a human reader but has the drawback that the references are verbose.
1259
1260 The [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] URN[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[7~]^^>>path:#_ftn7]](%%) is the concatenation of the following parts, separated by special symbols like dot, equal, asterisk, comma, and parenthesis:^^ ^^
1261
1262 * SDMXprefix
1263 * SDMX-IM-package-name
1264 * class-name
1265 * agency-id
1266 * maintainedobject-id
1267 * maintainedobject-version
1268 * container-object-id [[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[8~]^^>>path:#_ftn8]]
1269 * object-id
1270
1271 The generic structure of the URN is the following:
1272
1273 SDMXprefix**.**SDMX-IM-package-name**.**class-name**=**agency-id**:**maintainedobject-id **(**maintainedobject-version**).***container-object-id**.**object-id
1274
1275 The **[[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] prefix** is “urn:sdmx:org”, always the same for all [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]].
1276
1277 The **[[SDMX-IM>>doc:sdmx:Glossary.SDMX Information Model.WebHome]]-package-name **is the concatenation of the string** **“[[sdmx>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]].infomodel.” with the package-name which the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] belongs to. For example, for referencing a [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] the SDMX-IM-package-name is “sdmx.infomodel.datastructure”, because the class [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] belongs to the package “datastructure”.
1278
1279 The **class-name** is the name of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] object class which the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] object belongs to (e.g., for referencing a [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] the class-name is “[[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]]”). The [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] can reference [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] that belong to the classes [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]], [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]], MeasureDimension, TimeDimension, PrimaryMeasure, DataAttribute, (% style="color:#e74c3c" %)Concept(%%), ConceptScheme, Codelist.
1280
1281 The **agency-id** is the acronym of the agency that owns the definition of the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]], for example for the Eurostat [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] the agency-id is “ESTAT”). The agency-id can be composite (for example AgencyA.Dept1.Unit2).
1282
1283 The **maintainedobject-id** is the name of the maintained object which the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] belongs to, and in case the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] itself is maintainable[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[9~]^^>>path:#_ftn9]](%%), coincides with the name of the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]]. Therefore the maintainedobject-id depends on the class of the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]]:
1284
1285 * if the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] is a [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]], which is a maintainable class, the maintainedobject-id is the [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] name ([[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]]-id);
1286 * if the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] is a [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]], MeasureDimension, TimeDimension, PrimaryMeasure or DataAttribute, which are not maintainable and belong to the DataStructure maintainable class, the maintainedobject-id is the name of the DataStructure (dataStructure-id) which the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] belongs to;
1287 * if the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] is a (% style="color:#e74c3c" %)Concept(%%), which is not maintainable and belongs to the ConceptScheme maintainable class, ,, ,,the maintainedobject-id is the name of the ConceptScheme (conceptScheme-id) which the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] belongs to;
1288 * if the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] is a ConceptScheme, which is a maintainable class, ,, ,,the maintainedobject-id is the name of the ConceptScheme (conceptScheme-id);
1289 * if the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] is a Codelist, which is a maintainable class, the maintainedobject-id is the Codelist name (codelist-id).
1290
1291 The **maintainedobject-(% style="color:#e74c3c" %)version(%%)** is the (% style="color:#e74c3c" %)version(%%) of the maintained object which the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] belongs to (for example, possible (% style="color:#e74c3c" %)versions(%%) are 1.0, 2.1, 3.1.2).
1292
1293 The **container-object-id** does not apply to the classes that can be referenced in [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] transformations, therefore is not present in their URN
1294
1295 The **object-id** is the name of the non-[[maintainable artefact>>doc:sdmx:Glossary.Maintainable artefact.WebHome]] (when the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] is maintainable its name is already specified as the maintainedobject-id, see above), in particular it has to be specified:
1296
1297 * if the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] is a [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]], MeasureDimension, TimeDimension, PrimaryMeasure or DataAttribute (the object-id is the name of one of the [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] above, which are data structure [[components>>doc:sdmx:Glossary.Component.WebHome]])
1298 * if the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] is a (% style="color:#e74c3c" %)Concept(%%) (the object-id is the name of the (% style="color:#e74c3c" %)Concept(%%))
1299
1300 For example, by using the URN, the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] transformation that sums two [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[dataflows>>doc:sdmx:Glossary.Dataflow.WebHome]] DF1 and DF2 and assigns the result to a third persistent [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] DFR, assuming that DF1, DF2 and DFR are the maintainedobject-id of the three [[dataflows>>doc:sdmx:Glossary.Dataflow.WebHome]], that their (% style="color:#e74c3c" %)version(%%) is 1.0 and their Agency is AG, would be written as[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[10~]^^>>path:#_ftn10]](%%):
1301
1302 ‘urn:sdmx:org.sdmx.infomodel.datastructure.Dataflow=AG:DFR(1.0)’  <-
1303 ‘urn:sdmx:org.sdmx.infomodel.datastructure.Dataflow=AG:DF1(1.0)’  +
1304 ‘urn:sdmx:org.sdmx.infomodel.datastructure.Dataflow=AG:DF2(1.0)’
1305
1306 === 10.2.3 Abbreviation of the URN ===
1307
1308 The complete formulation of the URN described above is exhaustive but verbose, even for very simple statements. In order to reduce the verbosity through a simplified identifier and make the work of transformation definers easier, proper abbreviations of the URN are possible. Using this approach, the referenced [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] remain intelligible in the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] code by a human reader.
1309
1310 The URN can be abbreviated by omitting the parts that are not essential for the identification of the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] or that can be deduced from other available information, including the context in which the invocation is made. The possible abbreviations are described below.
1311
1312 * The **SDMXPrefix** can be omitted for all the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] objects, because it is a prefixed string (urn:[[sdmx>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]]:org), always the same for [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] objects.
1313 * The **[[SDMX-IM>>doc:sdmx:Glossary.SDMX Information Model.WebHome]]-package-name **can be omitted as well because it can be deduced from the class-name that follows it (the table of the [[SDMX-IM>>doc:sdmx:Glossary.SDMX Information Model.WebHome]] packages and classes that allows this deduction is in the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] 2.1 Standards - Section 5 - Registry Specifications, paragraph 6.2.3). In particular, considering the object classes of the [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] that [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] can reference, the package is: 
1314 ** “datastructure” for the classes [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]], [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]], MeasureDimension, TimeDimension, PrimaryMeasure, DataAttribute,
1315 ** “conceptscheme” for the classes (% style="color:#e74c3c" %)Concept(%%) and ConceptScheme
1316 ** “codelist” for the class Codelist.
1317 * The **class-name** can be omitted as it can be deduced from the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] invocation. In particular, starting from the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] class of the invoked [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] (e.g. [[dataset>>doc:sdmx:Glossary.Data set.WebHome]], [[component>>doc:sdmx:Glossary.Component.WebHome]], identifier, [[measure>>doc:sdmx:Glossary.Measure.WebHome]], [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]], variable, valuedomain), which is known given the syntax of the invoking [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] operator[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[11~]^^>>path:#_ftn11]](%%), the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] class can be deduced from the mapping rules between [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] and [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] (see the section “Mapping between [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] and [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]]” hereinafter)[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[12~]^^>>path:#_ftn12]](%%).
1318 * If the **agency-id** is not specified, it is assumed by default equal to the agency-id of the TransformationScheme, UserDefinedOperatorScheme or RulesetScheme from which the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] is invoked. For example, the agency-id can be omitted if it is the same as the invoking TransformationScheme and cannot be omitted if the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] comes from another agency.[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[13~]^^>>path:#_ftn13]](%%) Take also into account that, according to the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] consistency rules, the agency of the result of a Transformation must be the same as its TransformationScheme, therefore the agency-id can be omitted for all the results (left part of Transformation statements).
1319 * As for the **maintainedobject-id**, this is essential in some cases while in other cases it can be omitted: o if the referenced [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] is a [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]], which is a maintainable class, the maintainedobject-id is the [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]]-id and obviously cannot be omitted;
1320 ** if the referenced [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] is a [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]], MeasureDimension, TimeDimension, PrimaryMeasure, DataAttribute, which are not maintainable and belong to the DataStructure maintainable class, the maintainedobject-id is the dataStructure-id and can be omitted, given that these [[components>>doc:sdmx:Glossary.Component.WebHome]] are always invoked within the invocation of a [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]], whose dataStructure-id can be deduced from the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] structural definitions;
1321 ** if the referenced [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] is a (% style="color:#e74c3c" %)Concept(%%), which is not maintainable and belong to the ConceptScheme maintainable class,,, ,,the maintained object is the conceptScheme-id and cannot be omitted;
1322 ** if the referenced [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] is a ConceptScheme, which is a,, ,,maintainable class,,, ,,the maintained object is the conceptScheme-id and obviously cannot be omitted;
1323 ** if the referenced [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] is a Codelist, which is a maintainable class, the maintainedobject-id is the codelist-id and obviously cannot be omitted.
1324 * When the maintainedobject-id is omitted, the **maintainedobject-(% style="color:#e74c3c" %)version(%%)** is omitted too. When the maintainedobject-id is not omitted and the maintainedobject-(% style="color:#e74c3c" %)version(%%) is omitted, the (% style="color:#e74c3c" %)version(%%) 1.0 is assumed by default.,, ,,
1325 * As said, the **container-object-id** does not apply to the classes that can be referenced in [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] transformations, therefore is not present in their URN
1326 * The **object-id** does not exist for the [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] belonging to the [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]], ConceptScheme and Codelist classes, while it exists and cannot be omitted for the [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] belonging to the classes [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]], MeasureDimension, TimeDimension, PrimaryMeasure, DataAttribute and (% style="color:#e74c3c" %)Concept(%%), as for them the object-id is the main identifier of the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]]
1327
1328 The simplified object identifier is obtained by omitting all the first part of the URN, including the special characters, till the first part not omitted.
1329
1330 For example, the full formulation that uses the complete URN shown at the end of the previous paragraph:
1331
1332 ‘urn:sdmx:org.sdmx.infomodel.datastructure.Dataflow=AG:DFR(1.0)’  :=
1333 ‘urn:sdmx:org.sdmx.infomodel.datastructure.Dataflow=AG:DF1(1.0)’   +
1334 ‘urn:sdmx:org.sdmx.infomodel.datastructure.Dataflow=AG:DF2(1.0)’
1335
1336 by omitting all the non-essential parts would become simply:
1337
1338 DFR := DF1 + DF2
1339
1340 The references to the Codelists can be simplified similarly. For example, given the non-abbreviated reference to the Codelist AG:CL_FREQ(1.0), which is[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[14~]^^>>path:#_ftn14]](%%):
1341
1342 ‘urn:sdmx:org.sdmx.infomodel.codelist.Codelist=AG:CL_FREQ(1.0)’
1343
1344 if the Codelist is referenced from a ruleset scheme belonging to the agency AG, omitting all the optional parts, the abbreviated reference would become simply[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[15~]^^>>path:#_ftn15]](%%):
1345
1346 CL_FREQ
1347
1348 As for the references to the components, it can be enough to specify the componentId, given that the dataStructure-Id can be omitted. An example of non-abbreviated reference, if the data structure is DST1 and the component is SECTOR, is the following:
1349
1350 ‘urn:sdmx:org.sdmx.infomodel.datastructure.DataStructure=AG:DST1(1.0).SECTOR’
1351
1352 The corresponding fully abbreviated reference, if made from a transformation scheme belonging to AG, would become simply:
1353
1354 SECTOR
1355
1356 For example, the transformation for renaming the [[component>>doc:sdmx:Glossary.Component.WebHome]] SECTOR of the [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] DF1 into SEC can be written as[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[16~]^^>>path:#_ftn16]](%%):
1357
1358 ‘DFR(1.0)’ := ‘DF1(1.0)’ [rename SECTOR to SEC]
1359
1360 In the references to the (% style="color:#e74c3c" %)Concepts(%%), which can exist for example in the definition of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Rulesets, at least the conceptScheme-id and the (% style="color:#e74c3c" %)concept(%%)-id must be specified.
1361
1362 An example of non-abbreviated reference, if the conceptScheme-id is CS1 and the (% style="color:#e74c3c" %)concept(%%)-id is SECTOR, is the following:
1363
1364 ‘urn:[[sdmx>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]]:org.[[sdmx>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]].infomodel.conceptscheme.(% style="color:#e74c3c" %)Concept(%%)=AG:CS1(1.0).SECTOR’
1365
1366 The corresponding fully abbreviated reference, if made from a RulesetScheme belonging to AG, would become simply:
1367
1368 CS1(1.0).SECTOR
1369
1370 The [[Codes>>doc:sdmx:Glossary.Code.WebHome]] and in general all the Values can be written without any other specification, for example, the transformation to check if the values of the [[measures>>doc:sdmx:Glossary.Measure.WebHome]] of the [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] DF1 are between 0 and 25000 can be written like follows:
1371
1372 ‘DFR(1.0)’ := between ( ‘DF1(1.0)’, 0, 25000 )
1373
1374 The [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] ([[component>>doc:sdmx:Glossary.Component.WebHome]], (% style="color:#e74c3c" %)concept(%%), codelist …) which the Values are referred to can be deduced from the context in which the reference is made, taking also into account the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] syntax. In the transformation above, for example, the values 0 and 2500 are compared to the values of the [[measures>>doc:sdmx:Glossary.Measure.WebHome]] of DF1(1.0).
1375
1376 === 10.2.4 User-defined alias ===
1377
1378 The third possibility for referencing [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] from [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] statements is to use user-defined aliases not related to the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] URN of the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]].
1379
1380 This approach gives preference to the use of symbolic names for the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]]. As a consequence, in the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] code the referenced [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] would become not directly intelligible by a human reader. In any case, the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] aliases are associated to the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] URN through the VtlMappingScheme and VtlMapping classes. These classes provide for structured references to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] whatever kind of reference is used in [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] statements (URN, abbreviated URN or user-defined aliases).
1381
1382 === 10.2.5 References to SDMX artefacts from VTL Rulesets ===
1383
1384 The [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Rulesets allow defining sets of reusable rules that can be applied by some
1385
1386 [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] operators, like the ones for validation and hierarchical roll-up. A “rule” consists in a relationship between Values belonging to some Value Domains or taken by some Variables, for example: when the Country is USA then the [[Currency>>doc:sdmx:Glossary.Currency.WebHome]] is USD; (ii) the Benelux is composed by Belgium, Luxembourg, Netherlands.
1387
1388 The [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Rulesets have a signature, in which the Value Domains or the Variables on which the Ruleset is defined are declared, and a body, which contains the rules.
1389
1390 In the signature, given the mapping between [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] and [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] better described in the following paragraphs, a reference to a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Value Domain becomes a reference to a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] Codelist or to a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] ConceptScheme (for [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[measure>>doc:sdmx:Glossary.Measure.WebHome]] [[dimensions>>doc:sdmx:Glossary.Dimension.WebHome]]), while a reference to a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Represented Variable becomes a reference to a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] (% style="color:#e74c3c" %)Concept(%%), assuming for it a definite representation[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[17~]^^>>path:#_ftn17]](%%).
1391
1392 In general, for referencing [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] Codelists and (% style="color:#e74c3c" %)Concepts(%%), the conventions described in the previous paragraphs apply. In the Ruleset syntax, the elements that reference [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] are called “valueDomain” and “variable” for the Datapoint Rulesets and “ruleValueDomain”, “ruleVariable”, “condValueDomain” “condVariable” for the Hierarchical Rulesets). The syntax of the Ruleset signature allows also to define aliases of the elements above, these aliases are valid only within the specific ruleset definition statement and cannot be (% style="color:#e74c3c" %)mapped(%%) to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]].[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[18~]^^>>path:#_ftn18]](%%)
1393
1394 In the body of the Rulesets, the [[Codes>>doc:sdmx:Glossary.Code.WebHome]] and in general all the Values can be written without any other specification, because the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] which the Values are referred (Codelist, ConceptScheme, (% style="color:#e74c3c" %)Concept(%%)) to can be deduced from the Ruleset signature.
1395
1396 == 10.3 Mapping between SDMX and VTL artefacts ==
1397
1398 === 10.3.1 When the mapping occurs ===
1399
1400 The mapping methods between the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] and [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] object classes allow transforming a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] definition in a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] one and vice-versa for the [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] to be manipulated.
1401
1402 It should be remembered that [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] programs (i.e. Transformation Schemes) are represented in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] through the TransformationScheme maintainable class which is composed of Transformations (nameable [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]]). Each Transformation assigns the outcome of the evaluation of a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] expression to a result: the input operands of the expression and the result can be [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]].
1403
1404 Every time a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] object is referenced in a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Transformation as an input operand, there is the need to generate a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] definition of the object, so that the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] operations can take place. This can be made starting from the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] definition and applying a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]]-[[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] mapping method in the direction from [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]]. The possible mapping methods from [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] are described in the following paragraphs and are conceived to allow the automatic deduction of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] definition of the object from the knowledge of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] definition.
1405
1406 In the opposite direction, every time an object calculated by means of [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] must be treated as a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] object (for example for exchanging it through [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]]), there is the need of a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] definition of the object, so that the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] operations can take place. The [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] definition is needed for the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] objects for which a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] use is envisaged[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[19~]^^>>path:#_ftn19]](%%).
1407
1408 The mapping methods from [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] are described in the following paragraphs as well, however they do not allow the complete [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] definition to be automatically deduced from the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] definition, more than all because the former typically contains additional information in respect to the latter. For example, the definition of a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] includes also some mandatory information not available in [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] (like the [[concept scheme>>doc:sdmx:Glossary.Concept scheme.WebHome]] to which the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[components>>doc:sdmx:Glossary.Component.WebHome]] refer, the assignmentStatus and attributeRelationship for the DataAttributes and so on). Therefore the mapping methods from [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] provide only a general guidance for generating [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] definitions properly starting from the information available in [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]], independently of how the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] definition it is actually generated (manually, automatically or part and part).
1409
1410 === 10.3.2 General mapping of VTL and SDMX data structures ===
1411
1412 This section makes reference to the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] “Model for data and their structure”[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[20~]^^>>path:#_ftn20]](%%) and the correspondent [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] “[[Data Structure Definition>>doc:sdmx:Glossary.Data structure definition.WebHome]]”[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[21~]^^>>path:#_ftn21]](%%).
1413
1414 The main type of [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] that the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] can manipulate is the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Data Set>>doc:sdmx:Glossary.Data set.WebHome]], which in general is (% style="color:#e74c3c" %)mapped(%%) to the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]]. This means that a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Transformation, in the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] context, expresses the algorithm for calculating a derived [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] starting from some already existing [[Dataflows>>doc:sdmx:Glossary.Dataflow.WebHome]] (either collected or derived).[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[22~]^^>>path:#_ftn22]](%%)
1415
1416 While the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Transformations are defined in term of [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] definitions, they are assumed to be executed on instances of such [[Dataflows>>doc:sdmx:Glossary.Dataflow.WebHome]], provided at runtime to the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] engine (the mechanism for identifying the instances to be processed are not part of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] specifications and depend on the implementation of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]]-based systems). As already said, the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Datasets>>doc:sdmx:Glossary.Data set.WebHome]] are instances of [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Dataflows>>doc:sdmx:Glossary.Dataflow.WebHome]], therefore a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Transformation defined on some [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Dataflows>>doc:sdmx:Glossary.Dataflow.WebHome]] can be applied on some corresponding [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Datasets>>doc:sdmx:Glossary.Data set.WebHome]].
1417
1418 A [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Data Set>>doc:sdmx:Glossary.Data set.WebHome]] is structured by one and just one Data Structure and a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Data Structure can structure any number of [[Data Sets>>doc:sdmx:Glossary.Data set.WebHome]]. Correspondingly, in the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] context a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] is structured by one and just one DataStructureDefinition and one DataStructureDefinition can structure any number of [[Dataflows>>doc:sdmx:Glossary.Dataflow.WebHome]].
1419
1420 A [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Data Set>>doc:sdmx:Glossary.Data set.WebHome]] has a Data Structure made of [[Components>>doc:sdmx:Glossary.Component.WebHome]], which in turn can be Identifiers, [[Measures>>doc:sdmx:Glossary.Measure.WebHome]] and [[Attributes>>doc:sdmx:Glossary.Attribute.WebHome]]. Similarly, a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] DataflowDefinition has a DataStructureDefinition made of [[components>>doc:sdmx:Glossary.Component.WebHome]] that can be DimensionComponents, PrimaryMeasure and DataAttributes. In turn, a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] DimensionComponent can be a [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]], a TimeDimension or a MeasureDimension. Correspondingly, in the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] implementation of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]], the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Identifiers can be (optionally) distinguished in three sub-classes (Simple Identifier, Time Identifier, [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] Identifier) even if such a distinction is not evidenced in the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] IM.
1421
1422 However, a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Data Structure can have any number of Identifiers, [[Measures>>doc:sdmx:Glossary.Measure.WebHome]] and [[Attributes>>doc:sdmx:Glossary.Attribute.WebHome]], while a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] 2.1 DataStructureDefinition can have any number of [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] and DataAttributes but just one PrimaryMeasure[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[23~]^^>>path:#_ftn23]](%%). This is due to a difference between [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] 2.1 and [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] in the possible [[representation>>doc:sdmx:Glossary.Representation.WebHome]] methods of the data that contain more [[measures>>doc:sdmx:Glossary.Measure.WebHome]].
1423
1424 As for [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]], because the data structure cannot contain more than one [[measure>>doc:sdmx:Glossary.Measure.WebHome]] [[component>>doc:sdmx:Glossary.Component.WebHome]] (i.e., the primaryMeasure), the [[representation>>doc:sdmx:Glossary.Representation.WebHome]] of data having more [[measures>>doc:sdmx:Glossary.Measure.WebHome]] is possible only by means of a particular [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]], called MeasureDimension, which is aimed at containing the name of the [[measure>>doc:sdmx:Glossary.Measure.WebHome]] (% style="color:#e74c3c" %)concepts(%%), so that for each observation the value contained in the PrimaryMeasure [[component>>doc:sdmx:Glossary.Component.WebHome]] is the value of the [[measure>>doc:sdmx:Glossary.Measure.WebHome]] (% style="color:#e74c3c" %)concept(%%) reported in the MeasureDimension [[component>>doc:sdmx:Glossary.Component.WebHome]].
1425
1426 Instead [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] allows either the method above (an identifier containing the name of the [[measure>>doc:sdmx:Glossary.Measure.WebHome]] together with just one [[measure>>doc:sdmx:Glossary.Measure.WebHome]] [[component>>doc:sdmx:Glossary.Component.WebHome]]) or a more generic method that consists in defining more [[measure>>doc:sdmx:Glossary.Measure.WebHome]] [[components>>doc:sdmx:Glossary.Component.WebHome]] in the data structure, one for each [[measure>>doc:sdmx:Glossary.Measure.WebHome]].
1427
1428 Therefore for multi-[[measure>>doc:sdmx:Glossary.Measure.WebHome]] data more mapping options are possible, as described in more detail in the following sections.
1429
1430 === 10.3.3 Mapping from SDMX to VTL data structures ===
1431
1432 ==== 10.3.3.1 Basic Mapping** ** ====
1433
1434 The main mapping method from [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] is called **Basic **mapping. This is considered as the default mapping method and is applied unless a different method is specified through the VtlMappingScheme and VtlDataflowMapping classes.
1435
1436 When transforming **from [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]]**, this method consists in leaving the [[components>>doc:sdmx:Glossary.Component.WebHome]] unchanged and maintaining their names and roles, according to the following table:
1437
1438 (% style="width:636.294px" %)
1439 |(% style="width:286px" %)**SDMX**|(% style="width:347px" %)**VTL**
1440 |(% style="width:286px" %)[[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]]|(% style="width:347px" %)(Simple) Identifier
1441 |(% style="width:286px" %)Time [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]]|(% style="width:347px" %)(Time) Identifier
1442 |(% style="width:286px" %)[[Measure>>doc:sdmx:Glossary.Measure.WebHome]] [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]]|(% style="width:347px" %)([[Measure>>doc:sdmx:Glossary.Measure.WebHome]]) Identifier
1443 |(% style="width:286px" %)Primary [[Measure>>doc:sdmx:Glossary.Measure.WebHome]]|(% style="width:347px" %)[[Measure>>doc:sdmx:Glossary.Measure.WebHome]]
1444 |(% style="width:286px" %)Data [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]]|(% style="width:347px" %)[[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]]
1445
1446 According to this method, the resulting [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] structures are always mono-[[measure>>doc:sdmx:Glossary.Measure.WebHome]] (i.e., they have just one [[measure>>doc:sdmx:Glossary.Measure.WebHome]] [[component>>doc:sdmx:Glossary.Component.WebHome]]) and their [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] is the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] PrimaryMeasure. Nevertheless, if the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] data structure has a MeasureDimension, which can convey the name of one or more [[measure>>doc:sdmx:Glossary.Measure.WebHome]] (% style="color:#e74c3c" %)concepts(%%), such unique [[measure>>doc:sdmx:Glossary.Measure.WebHome]] [[component>>doc:sdmx:Glossary.Component.WebHome]] can contain the value of more (conceptual) [[measures>>doc:sdmx:Glossary.Measure.WebHome]] (one for each observation).
1447
1448 As for the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] DataAttributes, in [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] they are all considered “at data point / observation (% style="color:#e74c3c" %)level(%%)” (i.e. dependent on all the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Identifiers), because [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] does not have the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] AttributeRelationships, which defines the construct to which the DataAttribute is related (e.g. observation, [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]] or set or group of [[dimensions>>doc:sdmx:Glossary.Dimension.WebHome]], whole [[data set>>doc:sdmx:Glossary.Data set.WebHome]]).
1449
1450 With the Basic mapping, one [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] observation generates one [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] data point.
1451
1452 ==== 10.3.3.2 Pivot Mapping ====
1453
1454 An alternative mapping method from [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] is the **Pivot **mapping, which is different from the Basic method only for the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] data structures that contain a MeasureDimension, which are (% style="color:#e74c3c" %)mapped(%%) to multi-[[measure>>doc:sdmx:Glossary.Measure.WebHome]] [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] data structures.
1455
1456 The [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] structures that do not contain a MeasureDimension are (% style="color:#e74c3c" %)mapped(%%) like in the Basic mapping (see the previous paragraph).
1457
1458 The [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] structures that contain a MeasureDimension are (% style="color:#e74c3c" %)mapped(%%) as follows (this mapping is equivalent to a pivoting operation):
1459
1460 * A [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] simple [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]] becomes a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] (simple) identifier and a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] TimeDimension becomes a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] (time) identifier;
1461 * Each possible (% style="color:#e74c3c" %)Concept(%%) Cj of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] MeasureDimension is (% style="color:#e74c3c" %)mapped(%%) to a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Measure>>doc:sdmx:Glossary.Measure.WebHome]], having the same name as the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] (% style="color:#e74c3c" %)Concept(%%) (i.e. Cj); the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] Cj is a new [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[component>>doc:sdmx:Glossary.Component.WebHome]] even if the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] data structure has not such a [[Component>>doc:sdmx:Glossary.Component.WebHome]];
1462 * The [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] MeasureDimension is not (% style="color:#e74c3c" %)mapped(%%) to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] (it disappears in the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Data Structure);
1463 * The [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] PrimaryMeasure is not (% style="color:#e74c3c" %)mapped(%%) to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] as well (it disappears in the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Data Structure);
1464 * A [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] DataAttribute is (% style="color:#e74c3c" %)mapped(%%) in different ways according to its AttributeRelationship:
1465 ** If, according to the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] AttributeRelationship, the values of the DataAttribute do not depend on the values of the MeasureDimension, the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] DataAttribute becomes a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]] having the same name. This happens if the AttributeRelationship is not specified (i.e. the DataAttribute does not depend on any DimensionComponent and therefore is at [[data set>>doc:sdmx:Glossary.Data set.WebHome]] (% style="color:#e74c3c" %)level(%%)), or if it refers to a set (or a group) of [[dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] which does not include the MeasureDimension;
1466 ** Otherwise if, according to the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] AttributeRelationship, the values of the DataAttribute depend on the MeasureDimension, the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] DataAttribute is (% style="color:#e74c3c" %)mapped(%%) to one [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]] for each possible (% style="color:#e74c3c" %)Concept(%%) of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] MeasureDimension; by default, the names of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Attributes>>doc:sdmx:Glossary.Attribute.WebHome]] are obtained by concatenating the name of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] DataAttribute and the names of the correspondent
1467
1468 (% style="color:#e74c3c" %)Concept(%%) of the MeasureDimension separated by underscore; for example, if the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] DataAttribute is named DA and the possible (% style="color:#e74c3c" %)concepts(%%) of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] MeasureDimension are named C1, C2, …, Cn, then the corresponding [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Attributes>>doc:sdmx:Glossary.Attribute.WebHome]] will be named DA_C1, DA_C2, …, DA_Cn (if different names are desired, they can be achieved afterwards by renaming the [[Attributes>>doc:sdmx:Glossary.Attribute.WebHome]] through [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] operators). o Like in the Basic mapping, the resulting [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Attributes>>doc:sdmx:Glossary.Attribute.WebHome]] are considered as dependent on all the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] identifiers (i.e. “at data point / observation (% style="color:#e74c3c" %)level(%%)”), because [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] does not have the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] notion of [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]] Relationship.
1469
1470 The summary mapping table of the “pivot” mapping from [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] for the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] data structures that contain a MeasureDimension is the following:
1471
1472 (% style="width:941.294px" %)
1473 |(% style="width:441px" %)**SDMX**|(% style="width:497px" %)**VTL**
1474 |(% style="width:441px" %)[[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]]|(% style="width:497px" %)(Simple) Identifier
1475 |(% style="width:441px" %)TimeDimension|(% style="width:497px" %)(Time) Identifier
1476 |(% style="width:441px" %)MeasureDimension & PrimaryMeasure|(% style="width:497px" %)One [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] for each (% style="color:#e74c3c" %)Concept(%%) of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]]
1477 |(% style="width:441px" %)DataAttribute not depending on the MeasureDimension|(% style="width:497px" %)[[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]]
1478 |(% style="width:441px" %)DataAttribute depending on the MeasureDimension|(% style="width:497px" %)One [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]] for each (% style="color:#e74c3c" %)Concept(%%) of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]]
1479
1480 Using this mapping method, the [[components>>doc:sdmx:Glossary.Component.WebHome]] of the data structure can change in the conversion from [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] and it must be taken into account that the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] statements can reference only the [[components>>doc:sdmx:Glossary.Component.WebHome]] of the resulting [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] data structure.
1481
1482 At observation / data point (% style="color:#e74c3c" %)level(%%), calling Cj (j=1, … n) the j^^th^^ (% style="color:#e74c3c" %)Concept(%%) of the MeasureDimension:
1483
1484 * The set of [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] observations having the same values for all the [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] except than the MeasureDimension become one multi-[[measure>>doc:sdmx:Glossary.Measure.WebHome]] [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Data Point, having one [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] for each (% style="color:#e74c3c" %)Concept(%%) Cj of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] MeasureDimension;
1485 * The values of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] simple [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]], TimeDimension and DataAttributes not depending on the MeasureDimension (these [[components>>doc:sdmx:Glossary.Component.WebHome]] by definition have always the same values for all the observations of the set above) become the values of the corresponding [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] (simple) Identifiers, (time) Identifier and [[Attributes>>doc:sdmx:Glossary.Attribute.WebHome]].
1486 * The value of the PrimaryMeasure of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] observation belonging to the set above and having MeasureDimension=Cj becomes the value of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] Cj
1487 * For the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] DataAttributes depending on the MeasureDimension, the value of the DataAttribute DA of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] observation belonging to the set above and having MeasureDimension=Cj becomes the value of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]] DA_Cj
1488
1489 ==== 10.3.3.3 From SDMX DataAttributes to VTL Measures ====
1490
1491 * In some cases it may happen that the DataAttributes of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] DataStructure need to be managed as [[Measures>>doc:sdmx:Glossary.Measure.WebHome]] in [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]]. Therefore, a variant of both the methods above consists in transforming all the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] DataAttributes in [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Measures>>doc:sdmx:Glossary.Measure.WebHome]]. When DataAttributes are converted to [[Measures>>doc:sdmx:Glossary.Measure.WebHome]], the two methods above are called Basic_A2M and Pivot_A2M (the suffix “A2M” stands for [[Attributes>>doc:sdmx:Glossary.Attribute.WebHome]] to [[Measures>>doc:sdmx:Glossary.Measure.WebHome]]). Obviously, the resulting [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] data structure is, in general, multi-[[measure>>doc:sdmx:Glossary.Measure.WebHome]] and does not contain [[Attributes>>doc:sdmx:Glossary.Attribute.WebHome]].
1492
1493 The Basic_A2M and Pivot_A2M behaves respectively like the Basic and Pivot methods, except that the final [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[components>>doc:sdmx:Glossary.Component.WebHome]], which according to the Basic and Pivot methods would have had the role of [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]], assume instead the role of [[Measure>>doc:sdmx:Glossary.Measure.WebHome]].
1494
1495 Proper [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] features allow changing the role of specific [[attributes>>doc:sdmx:Glossary.Attribute.WebHome]] even after the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] mapping: they can be useful when only some of the DataAttributes need to be managed as [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Measures>>doc:sdmx:Glossary.Measure.WebHome]].
1496
1497 === 10.3.4 Mapping from VTL to SDMX data structures ===
1498
1499 ==== 10.3.4.1 Basic Mapping** ** ====
1500
1501 The main mapping method **from [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]]** is called **Basic **mapping as well.
1502
1503 This is considered as the default mapping method and is applied unless a different method is specified through the VtlMappingScheme and VtlDataflowMapping classes.
1504
1505 The method consists in leaving the [[components>>doc:sdmx:Glossary.Component.WebHome]] unchanged and maintaining their names and roles in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]], according to the following mapping table, which is the same as the basic mapping from [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]], only seen in the opposite direction.
1506
1507 This mapping method cannot be applied for [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] 2.1 if the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] data structure has more than one [[measure>>doc:sdmx:Glossary.Measure.WebHome]] [[component>>doc:sdmx:Glossary.Component.WebHome]], given that the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] 2.1 DataStructureDefinition allows just one [[measure>>doc:sdmx:Glossary.Measure.WebHome]] [[component>>doc:sdmx:Glossary.Component.WebHome]] (the PrimaryMeasure). In this case it becomes mandatory to specify a different mapping method through the VtlMappingScheme and VtlDataflowMapping classes.[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[24~]^^>>path:#_ftn24]](%%)
1508
1509 Please note that the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[measures>>doc:sdmx:Glossary.Measure.WebHome]] can have any name while in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] 2.1 the MeasureComponent has the mandatory name “obs_value”, therefore the name of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[measure>>doc:sdmx:Glossary.Measure.WebHome]] name must become “obs_value” in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] 2.1.
1510
1511 Mapping table:
1512
1513 (% style="width:592.294px" %)
1514 |(% style="width:253px" %)**VTL**|(% style="width:336px" %)**SDMX**
1515 |(% style="width:253px" %)(Simple) Identifier|(% style="width:336px" %)[[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]]
1516 |(% style="width:253px" %)(Time) Identifier|(% style="width:336px" %)TimeDimension
1517 |(% style="width:253px" %)([[Measure>>doc:sdmx:Glossary.Measure.WebHome]]) Identifier|(% style="width:336px" %)MeasureDimension
1518 |(% style="width:253px" %)[[Measure>>doc:sdmx:Glossary.Measure.WebHome]]|(% style="width:336px" %)PrimaryMeasure
1519 |(% style="width:253px" %)[[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]]|(% style="width:336px" %)DataAttribute
1520
1521 If the distinction between simple identifier, time identifier and [[measure>>doc:sdmx:Glossary.Measure.WebHome]] identifier is not maintained in the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] environment, the classification between [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]], TimeDimension and MeasureDimension exists only in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]], as declared in the relevant DataStructureDefinition.
1522
1523 Regarding the [[Attributes>>doc:sdmx:Glossary.Attribute.WebHome]], because [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] considers all of them “at observation (% style="color:#e74c3c" %)level(%%)”, the corresponding [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] DataAttributes should be put “at observation (% style="color:#e74c3c" %)level(%%)” as well (AttributeRelationships referred to the PrimaryMeasure), unless some other information about their AttributeRelationship is available.
1524
1525 Note that the basic mappings in the two directions (from [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] 2.1 to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] 2.0 and vice-versa) are (almost completely) reversible. In fact, if a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] 2.1 structure is (% style="color:#e74c3c" %)mapped(%%) to a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] structure and then the latter is (% style="color:#e74c3c" %)mapped(%%) back to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] 2.1, the resulting data structure is like the original one (apart for the AttributeRelationship, that can be different if the original [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] 2.1 structure contains DataAttributes that are not at observation (% style="color:#e74c3c" %)level(%%)). In reverse order, if a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] 2.0 mono-[[measure>>doc:sdmx:Glossary.Measure.WebHome]] structure is (% style="color:#e74c3c" %)mapped(%%) to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] 2.1 and then the latter is (% style="color:#e74c3c" %)mapped(%%) back to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] 2.0, the original data structure is obtained (apart from the name of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[measure>>doc:sdmx:Glossary.Measure.WebHome]], that in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] 2.1 must become “obs_value”).
1526
1527 As said, the resulting [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] definitions must be compliant with the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] consistency rules. For example, the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] must have the assignmentStatus, which does not exist in [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]], the AttributeRelationship for the DataAttributes and so on.
1528
1529 ==== 10.3.4.2 Unpivot Mapping ====
1530
1531 An alternative mapping method from [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] is the **Unpivot **mapping.
1532
1533 Although this mapping method can be used in any case, it makes major sense in case the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] data structure has more than one [[measure>>doc:sdmx:Glossary.Measure.WebHome]] [[component>>doc:sdmx:Glossary.Component.WebHome]] (multi-[[measures>>doc:sdmx:Glossary.Measure.WebHome]] [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] structure). For such [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] structures, in fact, the basic method cannot be applied, given that by maintaining the data structure unchanged the resulting [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] data structure would have more than one [[measure>>doc:sdmx:Glossary.Measure.WebHome]] [[component>>doc:sdmx:Glossary.Component.WebHome]], which is not allowed by [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] 2.1 (it allows just one [[measure>>doc:sdmx:Glossary.Measure.WebHome]] [[component>>doc:sdmx:Glossary.Component.WebHome]], the PrimaryMeasure, called “obs_value”).
1534
1535 The multi-[[measures>>doc:sdmx:Glossary.Measure.WebHome]] [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] structures have not a [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] Identifier (because the [[Measures>>doc:sdmx:Glossary.Measure.WebHome]] are separate [[components>>doc:sdmx:Glossary.Component.WebHome]]) and need to be converted to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[dataflows>>doc:sdmx:Glossary.Dataflow.WebHome]] having an added MeasureDimension which disambiguates the multiple [[measures>>doc:sdmx:Glossary.Measure.WebHome]], and an added PrimaryMeasure, in which the [[measures>>doc:sdmx:Glossary.Measure.WebHome]]’ values are maintained.
1536
1537 The **unpivot** mapping behaves like follows:
1538
1539 * like in the basic mapping, a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] (simple) identifier becomes a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] and a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] (time) identifier becomes a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] TimeDimension (as said, a [[measure>>doc:sdmx:Glossary.Measure.WebHome]] identifier cannot exist in multi-[[measure>>doc:sdmx:Glossary.Measure.WebHome]] [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] structures);
1540 * a MeasureDimension [[component>>doc:sdmx:Glossary.Component.WebHome]] called “measure_name” is added to the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] DataStructure;
1541 * a PrimaryMeasure [[component>>doc:sdmx:Glossary.Component.WebHome]] called “obs_value” is added to the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] DataStructure;
1542 * each [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] is (% style="color:#e74c3c" %)mapped(%%) to a (% style="color:#e74c3c" %)Concept(%%) of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] MeasureDimension having the same name as the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] (therefore all the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] [[Components>>doc:sdmx:Glossary.Component.WebHome]] do not originate [[Components>>doc:sdmx:Glossary.Component.WebHome]] in the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] DataStructure);
1543 * a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]] becomes a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] DataAttribute having AttributeRelationship referred to all the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] DimensionComponents including the TimeDimension and except the MeasureDimension.
1544
1545 The summary mapping table of the **unpivot** mapping method is the following:
1546
1547 (% style="width:904.294px" %)
1548 |(% style="width:291px" %)**VTL**|(% style="width:611px" %)**SDMX**
1549 |(% style="width:291px" %)(Simple) Identifier|(% style="width:611px" %)[[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]]
1550 |(% style="width:291px" %)(Time) Identifier|(% style="width:611px" %)TimeDimension
1551 |(% style="width:291px" %)All [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] [[Components>>doc:sdmx:Glossary.Component.WebHome]]|(% style="width:611px" %)(((
1552 MeasureDimension (having one [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] (% style="color:#e74c3c" %)Concept(%%) for each [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[measure>>doc:sdmx:Glossary.Measure.WebHome]] [[component>>doc:sdmx:Glossary.Component.WebHome]]) & PrimaryMeasure
1553 )))
1554 |(% style="width:291px" %)[[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]] |(% style="width:611px" %)(((
1555 DataAttribute depending on all [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] including the TimeDimension and except the MeasureDimension
1556 )))
1557
1558 At observation / data point (% style="color:#e74c3c" %)level(%%):
1559
1560 * a multi-[[measure>>doc:sdmx:Glossary.Measure.WebHome]] [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Data Point becomes a set of [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] observations, one for each [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[measure>>doc:sdmx:Glossary.Measure.WebHome]]
1561 * the values of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] identifiers become the values of the corresponding [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]], for all the observations of the set above
1562 * the name of the j^^th^^ [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[measure>>doc:sdmx:Glossary.Measure.WebHome]] (e.g. “Cj”) becomes the value of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] MeasureDimension of the j^^th^^ observation of the set (i.e. the (% style="color:#e74c3c" %)Concept(%%) Cj)
1563 * the value of the j^^th^^ [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[measure>>doc:sdmx:Glossary.Measure.WebHome]] becomes the value of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] PrimaryMeasure of the j^^th^^ observation of the set
1564 * the values of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Attributes>>doc:sdmx:Glossary.Attribute.WebHome]] become the values of the corresponding [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] DataAttributes (in principle for all the observations of the set above)
1565
1566 If desired, this method can be applied also to mono-[[measure>>doc:sdmx:Glossary.Measure.WebHome]] [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] structures, provided that none of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[components>>doc:sdmx:Glossary.Component.WebHome]] has already the role of [[measure>>doc:sdmx:Glossary.Measure.WebHome]] identifier.
1567
1568 Like in the general case, a MeasureDimension [[component>>doc:sdmx:Glossary.Component.WebHome]] called “measure_name” would be added to the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] DataStructure and would have just one possible [[measure>>doc:sdmx:Glossary.Measure.WebHome]] (% style="color:#e74c3c" %)concept(%%), corresponding to the unique [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[measure>>doc:sdmx:Glossary.Measure.WebHome]]. The original [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[measure>>doc:sdmx:Glossary.Measure.WebHome]] [[component>>doc:sdmx:Glossary.Component.WebHome]] would not become a [[Component>>doc:sdmx:Glossary.Component.WebHome]] in the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] data structure. The value of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[measure>>doc:sdmx:Glossary.Measure.WebHome]] would be assigned to the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] PrimaryMeasure called “obs_value”.
1569
1570 In any case, the resulting [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] definitions must be compliant with the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] consistency rules. For example, the possible (% style="color:#e74c3c" %)Concepts(%%) of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] MeasureDimension need to be listed in a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] ConceptScheme, with proper id, agency and (% style="color:#e74c3c" %)version(%%); moreover, the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] must have the assignmentStatus, which does not exist in [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]], the attributeRelationship for the DataAttributes and so on.
1571
1572 ==== 10.3.4.3 From VTL Measures to SDMX Data Attributes** ** ====
1573
1574 For the multi-[[measure>>doc:sdmx:Glossary.Measure.WebHome]] [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] structures (having more than one [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] [[Component>>doc:sdmx:Glossary.Component.WebHome]]), it may happen that the [[Measures>>doc:sdmx:Glossary.Measure.WebHome]] of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Data Structure need to be managed as DataAttributes in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]]. Therefore a third mapping method consists in transforming one [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[measure>>doc:sdmx:Glossary.Measure.WebHome]] in the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] primaryMeasure and all the other [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Measures>>doc:sdmx:Glossary.Measure.WebHome]] in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] DataAttributes. This method is called M2A (“M2A” stands for “[[Measures>>doc:sdmx:Glossary.Measure.WebHome]] to DataAttributes”).
1575
1576 When applied to mono-[[measure>>doc:sdmx:Glossary.Measure.WebHome]] [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] structures (having one [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] [[component>>doc:sdmx:Glossary.Component.WebHome]]), the M2A method behaves like the Basic mapping (the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] [[component>>doc:sdmx:Glossary.Component.WebHome]] becomes the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] primary [[measure>>doc:sdmx:Glossary.Measure.WebHome]] “obs_value”, there is no additional [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[measure>>doc:sdmx:Glossary.Measure.WebHome]] to be converted to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] DataAttribute). Therefore the mapping table is the same as for the Basic method:
1577
1578 (% style="width:591.294px" %)
1579 |(% style="width:252px" %)**VTL**|(% style="width:336px" %)**SDMX**
1580 |(% style="width:252px" %)(Simple) Identifier|(% style="width:336px" %)[[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]]
1581 |(% style="width:252px" %)(Time) Identifier|(% style="width:336px" %)TimeDimension
1582 |(% style="width:252px" %)([[Measure>>doc:sdmx:Glossary.Measure.WebHome]]) Identifier (if any)|(% style="width:336px" %)MeasureDimension
1583 |(% style="width:252px" %)[[Measure>>doc:sdmx:Glossary.Measure.WebHome]]|(% style="width:336px" %)PrimaryMeasure
1584 |(% style="width:252px" %)[[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]]|(% style="width:336px" %)DataAttribute
1585
1586 For multi-[[measure>>doc:sdmx:Glossary.Measure.WebHome]] [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] structures (having more than one [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] [[component>>doc:sdmx:Glossary.Component.WebHome]]), one [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] becomes the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] PrimaryMeasure while the other [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Measures>>doc:sdmx:Glossary.Measure.WebHome]] maintain their names and values but assume the role of DataAttribute in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]]. The choice of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Measure>>doc:sdmx:Glossary.Measure.WebHome]] that correspond to the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] PrimaryMeasure is left to the definer of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[data structure definition>>doc:sdmx:Glossary.Data structure definition.WebHome]].
1587
1588 Taking into account that the multi-[[measure>>doc:sdmx:Glossary.Measure.WebHome]] [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] structures do not have a [[measure>>doc:sdmx:Glossary.Measure.WebHome]] identifier, the mapping table is the following:
1589
1590 (% style="width:588.294px" %)
1591 |(% style="width:259px" %)**VTL**|(% style="width:326px" %)**SDMX**
1592 |(% style="width:259px" %)(Simple) Identifier|(% style="width:326px" %)[[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]]
1593 |(% style="width:259px" %)(Time) Identifier|(% style="width:326px" %)TimeDimension
1594 |(% style="width:259px" %)One of the [[Measures>>doc:sdmx:Glossary.Measure.WebHome]]|(% style="width:326px" %)PrimaryMeasure
1595 |(% style="width:259px" %)Other [[Measures>>doc:sdmx:Glossary.Measure.WebHome]]|(% style="width:326px" %)DataAttribute
1596 |(% style="width:259px" %)[[Attribute>>doc:sdmx:Glossary.Attribute.WebHome]]|(% style="width:326px" %)DataAttribute
1597
1598 Even in this case, the resulting [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] definitions must be compliant with the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] consistency rules. For example, the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] must have the assignmentStatus, which does not exist in [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]], the attributeRelationship for the DataAttributes and so on. In particular, the primaryMeasure of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] 2.1 [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] must be called “obs_value” and must be one of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[Measures>>doc:sdmx:Glossary.Measure.WebHome]], chosen by the [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] definer.
1599
1600 === 10.3.5 Declaration of the mapping methods between data structures ===
1601
1602 In order to define and understand properly [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] transformations, the applied mapping methods must be specified in the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[structural metadata>>doc:sdmx:Glossary.Structural metadata.WebHome]]. If the default mapping method (Basic) is applied, no specification is needed.
1603
1604 A customized mapping can be defined through the VtlMappingScheme and VtlDataflowMapping classes (see the section of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] IM relevant to the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]]). A VtlDataflowMapping allows specifying the mapping methods to be used for a specific [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]], both in the direction from [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] (toVtlMappingMethod) and from [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] (fromVtlMappingMethod); in fact a VtlDataflowMapping associates the structured URN that identifies a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] to its [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] alias and its mapping methods.
1605
1606 It is possible to specify the toVtlMappingMethod and fromVtlMappingMethod also for the conventional [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] called “generic_dataflow”: in this case the specified mapping methods are intended to become the default ones, overriding the “Basic” methods. In turn, the toVtlMappingMethod and fromVtlMappingMethod declared for a specific [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] are intended to override the default ones for such a [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]].
1607
1608 The VtlMappingScheme is a container for zero or more VtlDataflowMapping (besides possible mappings to [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] other than [[dataflows>>doc:sdmx:Glossary.Dataflow.WebHome]]).
1609
1610 === 10.3.6 Mapping dataflow subsets to distinct VTL data sets[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^**~[25~]**^^>>path:#_ftn25]](%%) ===
1611
1612 Until now it as been assumed to (% style="color:#e74c3c" %)map(%%) one SMDX [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] to one [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[dataset>>doc:sdmx:Glossary.Data set.WebHome]] and vice-versa. This mapping one-to-one is not mandatory according to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] because a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[data set>>doc:sdmx:Glossary.Data set.WebHome]] is meant to be a set of observations (data points) on a logical plane, having the same logical data structure and the same general meaning, independently of the possible physical [[representation>>doc:sdmx:Glossary.Representation.WebHome]] or storage (see [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] 2.0 User Manual page 24), therefore a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] can be seen either as a unique set of data observations (corresponding to one [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[data set>>doc:sdmx:Glossary.Data set.WebHome]]) or as the union of many sets of data observations (each one corresponding to a distinct [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[data set>>doc:sdmx:Glossary.Data set.WebHome]]).
1613
1614 As a matter of fact, in some cases it can be useful to define [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] operations involving definite parts of a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] instead than the whole.[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[26~]^^>>path:#_ftn26]](%%)
1615
1616 Therefore, in order to make the coding of [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] operations simpler when applied on parts of [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Dataflows>>doc:sdmx:Glossary.Dataflow.WebHome]], it is allowed to (% style="color:#e74c3c" %)map(%%) distinct parts of a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] to distinct [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[data sets>>doc:sdmx:Glossary.Data set.WebHome]] according to the following rules and conventions. This kind of mapping is possible both from [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] and from [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]], as better explained below.[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[27~]^^>>path:#_ftn27]](%%)
1617
1618 Given a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] and some predefined [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] of its DataStructure, it is allowed to (% style="color:#e74c3c" %)map(%%) the subsets of observations that have the same combination of values for such [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] to correspondent [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[datasets>>doc:sdmx:Glossary.Data set.WebHome]].
1619
1620 For example, assuming that the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] DF1(1.0) has the [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] INDICATOR, TIME_PERIOD and COUNTRY, and that the user declares the [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] INDICATOR and COUNTRY as basis for the mapping (i.e. the mapping [[dimensions>>doc:sdmx:Glossary.Dimension.WebHome]]): the observations that have the same values for INDICATOR and COUNTRY would be (% style="color:#e74c3c" %)mapped(%%) to the same [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[dataset>>doc:sdmx:Glossary.Data set.WebHome]] (and vice-versa).
1621
1622 In practice, this kind mapping is obtained like follows:
1623
1624 * For a given [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]], the user ([[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] definer) declares the [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]] [[components>>doc:sdmx:Glossary.Component.WebHome]] on which the mapping will be based, in a given order.[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[28~]^^>>path:#_ftn28]](%%) Following the example above, imagine that the user declares the [[dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] INDICATOR and COUNTRY.
1625 * The [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[dataset>>doc:sdmx:Glossary.Data set.WebHome]] is given a name using a special notation also called “ordered concatenation” and composed of the following parts: 
1626 ** The reference to the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] (expressed according to the rules described in the previous paragraphs, i.e. URN, abbreviated URN or another alias); for example DF(1.0);
1627 ** a slash (“/”) as a separator; [[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[29~]^^>>path:#_ftn29]]
1628 ** The reference to a specific part of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] above, expressed as the concatenation of the values that the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] declared above must have, separated by dots (“.”) and written in the order in which these [[dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] are defined[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[30~]^^>>path:#_ftn30]](%%). For example POPULATION.USA would mean that such a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[dataset>>doc:sdmx:Glossary.Data set.WebHome]] is (% style="color:#e74c3c" %)mapped(%%) to the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] observations for which the [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]] //INDICATOR// is equal to POPULATION and the [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]] //COUNTRY// is equal to USA.
1629
1630 In the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] transformations, this kind of [[dataset>>doc:sdmx:Glossary.Data set.WebHome]] name must be referenced between single quotes because the slash (“/”) is not a regular character according to the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] rules.
1631
1632 Therefore, the generic name of this kind of [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[datasets>>doc:sdmx:Glossary.Data set.WebHome]] would be:
1633
1634 > ‘DF(1.0)///INDICATORvalue//.//COUNTRYvalue//’
1635
1636 Where DF(1.0) is the [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] and //INDICATORvalue// and //COUNTRYvalue //are placeholders for one value of the INDICATOR and // //COUNTRY dimensions.
1637
1638 Instead the specific name of one of these [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[datasets>>doc:sdmx:Glossary.Data set.WebHome]] would be:
1639
1640 > ‘DF(1.0)/POPULATION.USA’
1641
1642 In particular, this is the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[dataset>>doc:sdmx:Glossary.Data set.WebHome]] that contains all the observations of the [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] DF(1.0) for which //INDICATOR// = POPULATION and //COUNTRY// = USA.
1643
1644 Let us now analyse the different meaning of this kind of mapping in the two mapping directions, i.e. from [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] and from [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]].
1645
1646 As already said, the mapping from [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] happens when the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[datasets>>doc:sdmx:Glossary.Data set.WebHome]] are operand of [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] transformations, instead the mapping from [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] happens when the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[datasets>>doc:sdmx:Glossary.Data set.WebHome]] are result of [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] transformations[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[31~]^^>>path:#_ftn31]](%%) and need to be treated as [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] objects. This kind of mapping can be applied independently in the two directions and the [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] on which the mapping is based can be different in the two directions: these [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] are defined in the ToVtlSpaceKey and in the FromVtlSpaceKey classes respectively.
1647
1648 First, let us see what happens in the__ mapping direction from [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]]__, i.e. when parts of a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] (e.g. DF1(1.0)) need to be (% style="color:#e74c3c" %)mapped(%%) to distinct [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[datasets>>doc:sdmx:Glossary.Data set.WebHome]] that are operand of some [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] transformations.
1649
1650 As already said, each [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[dataset>>doc:sdmx:Glossary.Data set.WebHome]] is assumed to contain all the observations of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] having INDICATOR=//INDICATORvalue //and COUNTRY=//COUNTRYvalue//. For example, the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[dataset>>doc:sdmx:Glossary.Data set.WebHome]] ‘DF1(1.0)/POPULATION.USA’ would contain all the observations of DF1(1.0) having INDICATOR = POPULATION and COUNTRY = USA.
1651
1652 In order to obtain the data structure of these [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[datasets>>doc:sdmx:Glossary.Data set.WebHome]] from the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] one, it is assumed that the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] on which the mapping is based are dropped, i.e. not maintained in the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] data structure; this is possible because their values are fixed for each one of the invoked [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[datasets>>doc:sdmx:Glossary.Data set.WebHome]][[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[32~]^^>>path:#_ftn32]](%%). After that, the mapping method from [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] specified for the [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] DF1(1.0) is applied (i.e. basic, pivot …).
1653
1654 In the example above, for all the [[datasets>>doc:sdmx:Glossary.Data set.WebHome]] of the kind ‘DF1(1.0)///INDICATORvalue//.//COUNTRYvalue//’, the [[dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] INDICATOR and COUNTRY would be dropped so that the data structure of all the resulting [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[data sets>>doc:sdmx:Glossary.Data set.WebHome]] would have the identifier TIME_PERIOD only.
1655
1656 It should be noted that the desired [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[datasets>>doc:sdmx:Glossary.Data set.WebHome]] (i.e. of the kind ‘DF1(1.0)/// INDICATORvalue//.//COUNTRYvalue//’) can be obtained also by applying the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] operator “**sub**” (subspace) to the [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] DF1(1.0), like in the following [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] expression:
1657
1658 > ‘DF1(1.0)/POPULATION.USA’ :=
1659 > DF1(1.0) [ sub INDICATOR=“POPULATION”, COUNTRY=“USA” ];
1660 > ‘DF1(1.0)/POPULATION.CANADA’ :=
1661 > DF1(1.0) [ sub INDICATOR=“POPULATION”, COUNTRY=“CANADA” ];
1662 > …   …   …
1663
1664 In fact the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] operator “sub” has exactly the same behaviour. Therefore, (% style="color:#e74c3c" %)mapping(%%) different parts of a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] to different [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[datasets>>doc:sdmx:Glossary.Data set.WebHome]] in the direction from [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] through the ordered concatenation notation is equivalent to a proper use of the operator “**sub**” on such a [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]]. [[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[33~]^^>>path:#_ftn33]]
1665
1666 In the direction from [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] it is allowed to omit the value of one or more [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] on which the (% style="color:#e74c3c" %)mapping(%%) is based, but maintaining all the separating dots (therefore it may happen to find two or more consecutive dots and dots in the beginning or in the end). The absence of value means that for the corresponding [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] all the values are kept and the [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] is not dropped.
1667
1668 For example, ‘DF(1.0)/POPULATION.’ (note the dot in the end of the name) is the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[dataset>>doc:sdmx:Glossary.Data set.WebHome]] that contains all the observations of the [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] DF(1.0) for which //INDICATOR// = POPULATION and COUNTRY = any value.
1669
1670 This is equivalent to the application of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] “sub” operator only to the identifier //INDICATOR//:
1671
1672 > ‘DF1(1.0)/POPULATION.’ := 
1673 > DF1(1.0) [sub INDICATOR=“POPULATION” ];
1674
1675 Therefore the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[dataset>>doc:sdmx:Glossary.Data set.WebHome]] ‘DF1(1.0)/POPULATION.’ would have the identifiers COUNTRY and TIME_PERIOD.
1676
1677 Heterogeneous invocations of the same [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] are allowed, i.e. omitting different [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] in different invocations.
1678
1679 Let us now analyse the __mapping direction from [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]]__.
1680
1681 In this situation, distinct parts of a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] are calculated as distinct [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[datasets>>doc:sdmx:Glossary.Data set.WebHome]], under the (% style="color:#e74c3c" %)constraint(%%) that they must have the same [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] data structure.
1682
1683 For example, let us assume that the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] programmer wants to calculate the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] DF2(1.0) having the [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] TIME_PERIOD, INDICATOR, and COUNTRY and that such a programmer finds it convenient to calculate separately the parts of DF2(1.0) that have different combinations of values for INDICATOR and COUNTRY:
1684
1685 * each part is calculated as a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] derived [[dataset>>doc:sdmx:Glossary.Data set.WebHome]], result of a dedicated [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] transformation; [[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[34~]^^>>path:#_ftn34]](%%)
1686 * the data structure of all these [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[datasets>>doc:sdmx:Glossary.Data set.WebHome]] has the TIME_PERIOD identifier and does not have the INDICATOR and COUNTRY identifiers.[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[35~]^^>>path:#_ftn35]]
1687
1688 Under these hypothesis, such derived [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[datasets>>doc:sdmx:Glossary.Data set.WebHome]] can be (% style="color:#e74c3c" %)mapped(%%) to DF2(1.0) by declaring the [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] INDICATOR and COUNTRY as mapping [[dimensions>>doc:sdmx:Glossary.Dimension.WebHome]][[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[36~]^^>>path:#_ftn36]](%%).
1689
1690 The corresponding [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] transformations, assuming that the result needs to be persistent, would be of this kind:^^ ^^[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[37~]^^>>path:#_ftn37]]
1691
1692
1693 ‘DF2(1.0)///INDICATORvalue//.//COUNTRYvalue//’  <-  expression
1694
1695 Some examples follow, for some specific values of INDICATOR and COUNTRY:
1696
1697 ‘DF2(1.0)/GDPPERCAPITA.USA’  <-   expression11;
1698 ‘DF2(1.0)/GDPPERCAPITA.CANADA’   <-   expression12;
1699 …   …   …
1700 ‘DF2(1.0)/POPGROWTH.USA’  <-   expression21;
1701 ‘DF2(1.0)/POPGROWTH.CANADA’  <-   expression22;
1702
1703 …   …   …
1704
1705 As said, it is assumed that these [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] derived [[datasets>>doc:sdmx:Glossary.Data set.WebHome]] have the TIME_PERIOD as the only identifier. In the mapping from [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] to SMDX, the [[Dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] INDICATOR and COUNTRY are added to the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] data structure on order to obtain the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] one, with the following values respectively:
1706
1707 (% contenteditable="false" tabindex="-1" %)[[image:1747859458410-183.png||data-widget="image" height="170" width="663"]]
1708
1709 It should be noted that the application of this many-to-one mapping from [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] is equivalent to an appropriate sequence of [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Transformations. These use the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] operator “calc” to add the proper [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] identifiers (in the example, INDICATOR and COUNTRY) and to assign to them the proper values and the operator “union” in order to obtain the final [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[dataset>>doc:sdmx:Glossary.Data set.WebHome]] (in the example DF2(1.0)), that can be (% style="color:#e74c3c" %)mapped(%%) one-to-one to the homonymous [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]]. Following the same example, these [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] transformations would be:
1710
1711 (% contenteditable="false" tabindex="-1" %)[[image:1747859612718-454.png||data-widget="image" height="451" width="602"]]
1712
1713 In other words, starting from the [[datasets>>doc:sdmx:Glossary.Data set.WebHome]] explicitly calculated through [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] (in the example ‘DF2(1.0)/GDPPERCAPITA.USA’ and so on), the first step consists in calculating other (non-persistent) [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[datasets>>doc:sdmx:Glossary.Data set.WebHome]] (in the example DF2bis_GDPPERCAPITA_USA and so on) by adding the identifiers INDICATOR and COUNTRY with the desired values (//INDICATORvalue// and //COUNTRYvalue)//. Finally, all these non-persistent [[data sets>>doc:sdmx:Glossary.Data set.WebHome]] are united and give the final result DF2(1.0)[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[38~]^^>>path:#_ftn38]](%%), which can be (% style="color:#e74c3c" %)mapped(%%) one-to-one to the homonymous [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] having the [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]] [[components>>doc:sdmx:Glossary.Component.WebHome]] TIME_PERIOD, INDICATOR and COUNTRY.
1714
1715 Therefore, (% style="color:#e74c3c" %)mapping(%%) different [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[datasets>>doc:sdmx:Glossary.Data set.WebHome]] having the same data structure to different parts of a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]], i.e. in the direction from [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]], through the ordered concatenation notation is equivalent to a proper use of the operators “calc” and “union” on such [[datasets>>doc:sdmx:Glossary.Data set.WebHome]]. [[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[39~]^^>>path:#_ftn39]](%%)[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[40~]^^>>path:#_ftn40]]
1716
1717 It is worth noting that in the direction from [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] it is mandatory to specify the value for every [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] on which the (% style="color:#e74c3c" %)mapping(%%) is based (in other word, in the name of the calculated [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[dataset>>doc:sdmx:Glossary.Data set.WebHome]] is not possible to omit the value of some of the Dimensions).
1718
1719 === 10.3.7 Mapping variables and value domains between VTL and SDMX ===
1720
1721 With reference to the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] “model for Variables and Value domains”, the following additional mappings have to be considered:
1722
1723 (% style="width:890.835px" %)
1724 |(% style="width:314px" %)VTL|(% style="width:574px" %)SDMX
1725 |(% style="width:314px" %)**[[Data Set>>doc:sdmx:Glossary.Data set.WebHome]] [[Component>>doc:sdmx:Glossary.Component.WebHome]]**|(% style="width:574px" %)Although this abstraction exists in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]], it does not have an explicit definition and correspond to a [[Component>>doc:sdmx:Glossary.Component.WebHome]] (either a [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]] or a PrimaryMeasure or a DataAttribute) belonging to one specific [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]]^^42^^
1726 |(% style="width:314px" %)**Represented Variable**|(% style="width:574px" %)(% style="color:#e74c3c" %)**Concept**(%%) with a definite [[Representation>>doc:sdmx:Glossary.Representation.WebHome]]
1727 |(% style="width:314px" %)**Value Domain**|(% style="width:574px" %)**[[Representation>>doc:sdmx:Glossary.Representation.WebHome]]** (see the Structure Pattern in the Base Package)
1728 |(% style="width:314px" %)**Enumerated Value Domain / [[Code List>>doc:sdmx:Glossary.Code list.WebHome]]**|(% style="width:574px" %)(((
1729 **Codelist** (for enumerated [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]], PrimaryMeasure, DataAttribute) or **ConceptScheme **(for MeasureDimension)
1730 )))
1731 |(% style="width:314px" %)**[[Code>>doc:sdmx:Glossary.Code.WebHome]]**|(% style="width:574px" %)**[[Code>>doc:sdmx:Glossary.Code.WebHome]]** (for enumerated [[Dimension>>doc:sdmx:Glossary.Dimension.WebHome]], PrimaryMeasure, DataAttribute) or (% style="color:#e74c3c" %)**Concept**(%%) (for MeasureDimension)
1732 |(% style="width:314px" %)**Described Value Domain**|(% style="width:574px" %)(((
1733 non-enumerated** [[Representation>>doc:sdmx:Glossary.Representation.WebHome]] **(having [[Facets>>doc:sdmx:Glossary.Facet.WebHome]] / ExtendedFacets, see the Structure Pattern in the Base Package)
1734 )))
1735 |(% style="width:314px" %)**Value**|(% style="width:574px" %)(((
1736 Although this abstraction exists in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]], it does not have an explicit definition and correspond to a **[[Code>>doc:sdmx:Glossary.Code.WebHome]]** of a Codelist (for enumerated [[Representations>>doc:sdmx:Glossary.Representation.WebHome]]) or to a valid **value **(for non-enumerated** **[[Representations>>doc:sdmx:Glossary.Representation.WebHome]]) or to a (% style="color:#e74c3c" %)**Concept**(%%)** **(for MeasureDimension)
1737 )))
1738 |(% style="width:314px" %)**Value Domain Subset / Set**|(% style="width:574px" %)This abstraction does not exist in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]]
1739 |(% style="width:314px" %)**Enumerated Value Domain Subset / Enumerated Set**|(% style="width:574px" %)This abstraction does not exist in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]]
1740 |(% style="width:314px" %)**Described Value Domain Subset / Described Set**|(% style="width:574px" %)This abstraction does not exist in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]]
1741 |(% style="width:314px" %)**Set list**|(% style="width:574px" %)This abstraction does not exist in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]]
1742
1743 The main difference between [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] and [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] relies on the fact that the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] for defining subsets of Value Domains do not exist in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]], therefore the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] features for referring to predefined subsets are not available in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]]. These [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] are the Value Domain Subset (or Set), either enumerated or described, the Set List (list of values belonging to enumerated subsets) and the [[Data Set>>doc:sdmx:Glossary.Data set.WebHome]] [[Component>>doc:sdmx:Glossary.Component.WebHome]] (aimed at defining the set of values that the [[Component>>doc:sdmx:Glossary.Component.WebHome]] of a [[Data Set>>doc:sdmx:Glossary.Data set.WebHome]] can take, possibly a subset of the [[codes>>doc:sdmx:Glossary.Code.WebHome]] of Value Domain).
1744
1745 Another difference consists in the fact that all Value Domains are considered as identifiable objects in [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] either if enumerated or not, while in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] the Codelist (corresponding to a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] enumerated Value Domain) is identifiable, while the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] non-enumerated [[Representation>>doc:sdmx:Glossary.Representation.WebHome]] (corresponding to a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] non-enumerated Value Domain) is not identifiable. As a consequence, the definition of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] rulesets, which in [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] can refer either to enumerated or non-enumerated value domains, in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] can refer only to enumerated Value Domains (i.e. to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] Codelists).
1746
1747 As for the (% style="color:#e74c3c" %)mapping(%%) between [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] variables and [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] (% style="color:#e74c3c" %)Concepts(%%), it should be noted that these [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] do not coincide perfectly. In fact, the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] variables are represented variables, defined always on the same Value Domain (“[[Representation>>doc:sdmx:Glossary.Representation.WebHome]]” in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]]) independently of the [[data set>>doc:sdmx:Glossary.Data set.WebHome]] / data structure in which they appear[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[41~]^^>>path:#_ftn41]](%%), while the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] (% style="color:#e74c3c" %)Concepts(%%) can have different [[Representations>>doc:sdmx:Glossary.Representation.WebHome]] in different DataStructures.[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[42~]^^>>path:#_ftn42]](%%) This means that one [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] (% style="color:#e74c3c" %)Concept(%%) can correspond to many [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Variables, one for each [[representation>>doc:sdmx:Glossary.Representation.WebHome]] the (% style="color:#e74c3c" %)Concept(%%) has.
1748
1749 Therefore, it is important to be aware that some [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] operations (for example the binary operations at [[data set>>doc:sdmx:Glossary.Data set.WebHome]] (% style="color:#e74c3c" %)level(%%)) are consistent only if the [[components>>doc:sdmx:Glossary.Component.WebHome]] having the same names in the operated [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[data sets>>doc:sdmx:Glossary.Data set.WebHome]] have also the same [[representation>>doc:sdmx:Glossary.Representation.WebHome]] (i.e. the same Value Domain as for [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]]). For example, it is possible to obtain correct results from the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] expression
1750
1751 DS_c := DS_a + DS_b (where DS_a, DS_b, DS_c are VTL Data Sets)
1752
1753 if the matching [[components>>doc:sdmx:Glossary.Component.WebHome]] in DS_a and DS_b (e.g. ref_date, geo_area, sector …) refer to the same general [[representation>>doc:sdmx:Glossary.Representation.WebHome]]. In simpler words, DS_a and DS_b must use the same values/[[codes>>doc:sdmx:Glossary.Code.WebHome]] (for ref_date, geo_area, sector … ), otherwise the relevant values would not match and the result of the operation would be wrong.
1754
1755 As mentioned, the property above is not enforced by construction in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]], and different [[representations>>doc:sdmx:Glossary.Representation.WebHome]] of the same (% style="color:#e74c3c" %)Concept(%%) can be not compatible one another (for example, it may happen that geo_area is represented by ISO-alpha-3 [[codes>>doc:sdmx:Glossary.Code.WebHome]] in DS_a and by ISO alpha-2 [[codes>>doc:sdmx:Glossary.Code.WebHome]] in DS_b). Therefore, it will be up to the definer of [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] transformations to ensure that the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] expressions are consistent with the actual [[representations>>doc:sdmx:Glossary.Representation.WebHome]] of the correspondent [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] (% style="color:#e74c3c" %)Concepts(%%).
1756
1757 It remains up to the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]]-[[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] definer also the assurance of the consistency between a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Ruleset defined on Variables and the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Components>>doc:sdmx:Glossary.Component.WebHome]] on which the Ruleset is applied. In fact, a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Ruleset is expressed by means of the values of the Variables (i.e. [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] (% style="color:#e74c3c" %)Concepts(%%)), i.e. assuming definite [[representations>>doc:sdmx:Glossary.Representation.WebHome]] for them (e.g. ISO-alpha-3 for country). If the Ruleset is applied to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Components>>doc:sdmx:Glossary.Component.WebHome]] that have the same name of the (% style="color:#e74c3c" %)Concept(%%) they refer to but different [[representations>>doc:sdmx:Glossary.Representation.WebHome]] (e.g. ISO-alpha-2 for country), the Ruleset cannot work properly.
1758
1759 == 10.4 Mapping between SDMX and VTL Data Types ==
1760
1761 === 10.4.1 VTL Data types ===
1762
1763 According to the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] User Guide the possible operations in [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] depend on the data types of the [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]]. For example, numbers can be multiplied but text strings cannot. In the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Transformations, the compliance between the operators and the data types of their operands is statically checked, i.e., violations result in compiletime errors.
1764
1765 The [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] data types are sub-divided in scalar types (like integers, strings, etc.), which are the types of the scalar values, and compound types (like [[data sets>>doc:sdmx:Glossary.Data set.WebHome]], [[components>>doc:sdmx:Glossary.Component.WebHome]], rulesets, etc.), which are the types of the compound structures. See below the diagram of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] data types, taken from the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] User Manual:
1766
1767 (% contenteditable="false" tabindex="-1" %)[[image:1747836776716-178.png||data-widget="image"]]
1768
1769 **Figure 12 – VTL Data Types**
1770
1771 The [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] scalar types are in turn subdivided in basic scalar types, which are elementary (not defined in term of other data types) and Value Domain and Set scalar types, which are defined in terms of the basic scalar types.
1772
1773 The [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] basic scalar types are listed below and follow a hierarchical structure in terms of supersets/subsets (e.g. “scalar” is the superset of all the basic scalar types):
1774
1775 (% contenteditable="false" tabindex="-1" %)[[image:1747859722732-549.png||data-widget="image" height="283" width="224"]]
1776
1777 **Figure 13 – VTL Basic Scalar Types**
1778
1779 === 10.4.2 VTL basic scalar types and SDMX data types ===
1780
1781 The [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] assumes that a basic scalar type has a unique internal [[representation>>doc:sdmx:Glossary.Representation.WebHome]] and can have more external [[representations>>doc:sdmx:Glossary.Representation.WebHome]].
1782
1783 The internal [[representation>>doc:sdmx:Glossary.Representation.WebHome]] is the format used within a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] system to represent (and process) all the scalar values of a certain type. In principle, this format is hidden and not necessarily known by users. The external [[representations>>doc:sdmx:Glossary.Representation.WebHome]] are instead the external formats of the values of a certain basic scalar type, i.e. the formats known by the users. For example, the internal [[representation>>doc:sdmx:Glossary.Representation.WebHome]] of the dates can be an integer counting the days since a predefined date (e.g. from 01/01/4713 BC up to 31/12/5874897 AD like in Postgres) while two possible external [[representations>>doc:sdmx:Glossary.Representation.WebHome]] are the formats YYYY-MM-GG and MM-GG-YYYY (e.g. respectively 2010-12-31 and 1231-2010).
1784
1785 The internal [[representation>>doc:sdmx:Glossary.Representation.WebHome]] is the reference format that allows [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] to operate on more values of the same type (for example on more dates) even if such values have different external formats: these values are all converted to the unique internal [[representation>>doc:sdmx:Glossary.Representation.WebHome]] so that they can be composed together (e.g. to find the more recent date, to find the time span between these dates and so on).
1786
1787 The [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] assumes that a unique internal [[representation>>doc:sdmx:Glossary.Representation.WebHome]] exists for each basic scalar type but does not prescribe any particular format for it, leaving the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] systems free to using they preferred or already existing internal format. By consequence, in [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] the basic scalar types are abstractions not associated to a specific format.
1788
1789 [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] data types are conceived instead to support the data exchange, therefore they do have a format, which is known by the users and correspond, in [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] terms, to external [[representations>>doc:sdmx:Glossary.Representation.WebHome]]. Therefore, for each [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] basic scalar type there can be more [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] data types (the latter are explained in the section “General Notes for Implementers” of this document and are actually much more numerous than the former).
1790
1791 The following paragraphs describe the mapping between the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] data types and the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] basic scalar types. This mapping shall be presented in the two directions of possible conversion, i.e. from [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] and vice-versa.
1792
1793 The conversion from [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] happens when an [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] acts as inputs of a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] transformation. As already said, in fact, at compile time the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] needs to know the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] type of the operands in order to check their compliance with the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] operators and at runtime it must convert the values from their external ([[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]]) [[representations>>doc:sdmx:Glossary.Representation.WebHome]] to the corresponding internal ([[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]]) ones.
1794
1795 The opposite conversion, i.e. from [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]], happens when a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] result, i.e. a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] [[data set>>doc:sdmx:Glossary.Data set.WebHome]] output of a transformation, must become a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] (or part of it). The values of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] result must be converted into the desired ([[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]]) external [[representations>>doc:sdmx:Glossary.Representation.WebHome]] (data types) of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]].
1796
1797 === 10.4.3 Mapping SDMX data types to VTL basic scalar types ===
1798
1799 The following table describes the default mapping for converting from the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] data types to the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] basic scalar types.
1800
1801 (% style="width:653.835px" %)
1802 |(% style="width:366px" %)**SDMX data type (BasicComponentDataType)**|(% style="width:284px" %)**Default [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] basic scalar type**
1803 |(% style="width:366px" %)(((
1804 **String**
1805 (string allowing any character)
1806 )))|(% style="width:284px" %)**string**
1807 |(% style="width:366px" %)(((
1808 **Alpha**
1809 (string which only allows A-z)
1810 )))|(% style="width:284px" %)**string**
1811 |(% style="width:366px" %)(((
1812 **AlphaNumeric**
1813 (string which only allows A-z and 0-9)
1814 )))|(% style="width:284px" %)**string**
1815 |(% style="width:366px" %)(((
1816 **Numeric**
1817 (string which only allows 0-9, but is not numeric so that is can having leading zeros)
1818 )))|(% style="width:284px" %)**string**
1819 |(% style="width:366px" %)(((
1820 **BigInteger**
1821 (corresponds to XML Schema xs:integer datatype; infinite set of integer values)
1822 )))|(% style="width:284px" %)**integer**
1823 |(% style="width:366px" %)(((
1824 **Integer**
1825 (corresponds to XML Schema xs:int datatype; between -2147483648 and +2147483647 (inclusive))
1826 )))|(% style="width:284px" %)**integer**
1827 |(% style="width:366px" %)(((
1828 **Long**
1829 (corresponds to XML Schema xs:long datatype; between -9223372036854775808 and +9223372036854775807 (inclusive))
1830 )))|(% style="width:284px" %)**integer**
1831 |(% style="width:366px" %)(((
1832 **Short**
1833 (corresponds to XML Schema xs:short datatype; between -32768 and -32767 (inclusive))
1834 )))|(% style="width:284px" %)**integer**
1835 |(% style="width:366px" %)(((
1836 **[[Decimal>>doc:sdmx:Glossary.Decimals.WebHome]]**
1837 (corresponds to XML Schema xs:[[decimal>>doc:sdmx:Glossary.Decimals.WebHome]] datatype; subset of real numbers that can be represented as decimals)
1838 )))|(% style="width:284px" %)**number**
1839 |(% style="width:366px" %)(((
1840 **Float**
1841 (corresponds to XML Schema xs:float datatype; patterned after the IEEE single-precision 32-bit floating point type)
1842 )))|(% style="width:284px" %)**number**
1843 |(% style="width:366px" %)(((
1844 **Double**
1845 (corresponds to XML Schema xs:double datatype; patterned after the IEEE double-precision 64-bit floating point type)
1846 )))|(% style="width:284px" %)**number**
1847 |(% style="width:366px" %)(((
1848 **Boolean**
1849 (corresponds to the XML Schema xs:boolean datatype; support the mathematical (% style="color:#e74c3c" %)concept(%%) of binary-valued logic: {true, false})
1850 )))|(% style="width:284px" %)**boolean**
1851 |(% style="width:366px" %)(((
1852 **URI**
1853 (corresponds to the XML Schema xs:anyURI; absolute or relative Uniform Resource Identifier Reference)
1854 )))|(% style="width:284px" %)**string**
1855 |(% style="width:366px" %)(((
1856 **Count**
1857 (an integer following a sequential pattern, increasing by 1 for each occurrence)
1858 )))|(% style="width:284px" %)**integer**
1859 |(% style="width:366px" %)(((
1860 **InclusiveValueRange**
1861 ([[decimal>>doc:sdmx:Glossary.Decimals.WebHome]] number within a closed interval, whose bounds are specified in the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[representation>>doc:sdmx:Glossary.Representation.WebHome]] by the [[facets>>doc:sdmx:Glossary.Facet.WebHome]] minValue and maxValue)
1862 )))|(% style="width:284px" %)**number**
1863 |(% style="width:366px" %)(((
1864 **ExclusiveValueRange**
1865 ([[decimal>>doc:sdmx:Glossary.Decimals.WebHome]] number within an open interval, whose bounds are specified in the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[representation>>doc:sdmx:Glossary.Representation.WebHome]] by the [[facets>>doc:sdmx:Glossary.Facet.WebHome]] minValue and maxValue)
1866 )))|(% style="width:284px" %)**number**
1867 |(% style="width:366px" %)(((
1868 **Incremental **
1869 ([[decimal>>doc:sdmx:Glossary.Decimals.WebHome]] number the increased by a specific interval (defined by the interval [[facet>>doc:sdmx:Glossary.Facet.WebHome]]), which is typically enforced outside of the XML validation)
1870 )))|(% style="width:284px" %)**number**
1871 |(% style="width:366px" %)(((
1872 **ObservationalTimePeriod**
1873 (superset of StandardTimePeriod and TimeRange)
1874 )))|(% style="width:284px" %)**time**
1875 |(% style="width:366px" %)(((
1876 **StandardTimePeriod**
1877 (superset of BasicTimePeriod and ReportingTimePeriod)
1878 )))|(% style="width:284px" %)**time**
1879 |(% style="width:366px" %)(((
1880 **BasicTimePeriod**
1881 (superset of GregorianTimePeriod and DateTime)
1882 )))|(% style="width:284px" %)**date**
1883 |(% style="width:366px" %)(((
1884 **GregorianTimePeriod**
1885 (superset of GregorianYear, GregorianYearMonth, and GregorianDay)
1886 )))|(% style="width:284px" %)**date**
1887 |(% style="width:366px" %)**GregorianYear **(YYYY)|(% style="width:284px" %)**date**
1888 |(% style="width:366px" %)**GregorianYearMonth** / **GregorianMonth** (YYYY-MM)|(% style="width:284px" %)**date**
1889 |(% style="width:366px" %)**GregorianDay **(YYYY-MM-DD)|(% style="width:284px" %)**date**
1890 |(% style="width:366px" %)(((
1891 **ReportingTimePeriod **
1892 (superset of RepostingYear, ReportingSemester, ReportingTrimester, ReportingQuarter, ReportingMonth, ReportingWeek, ReportingDay)
1893 )))|(% style="width:284px" %)**time_period**
1894 |(% style="width:366px" %)(((
1895 **ReportingYear**
1896 (YYYY-A1 – 1 year period)
1897 )))|(% style="width:284px" %)**time_period**
1898 |(% style="width:366px" %)(((
1899 **ReportingSemester**
1900 (YYYY-Ss – 6 month period)
1901 )))|(% style="width:284px" %)**time_period**
1902 |(% style="width:366px" %)(((
1903 **ReportingTrimester**
1904 (YYYY-Tt – 4 month period)
1905 )))|(% style="width:284px" %)**time_period**
1906 |(% style="width:366px" %)(((
1907 **ReportingQuarter**
1908 (YYYY-Qq – 3 month period)
1909 )))|(% style="width:284px" %)**time_period**
1910 |(% style="width:366px" %)(((
1911 **ReportingMonth**
1912 (YYYY-Mmm – 1 month period)
1913 )))|(% style="width:284px" %)**time_period**
1914 |(% style="width:366px" %)(((
1915 **ReportingWeek**
1916 (YYYY-Www – 7 day period; following ISO 8601 definition of a week in a year)
1917 )))|(% style="width:284px" %)**time_period**
1918 |(% style="width:366px" %)(((
1919 **ReportingDay**
1920 (YYYY-Dddd – 1 day period)
1921 )))|(% style="width:284px" %)**time_period**
1922 |(% style="width:366px" %)(((
1923 **DateTime**
1924 (YYYY-MM-DDThh:mm:ss)
1925 )))|(% style="width:284px" %)**date**
1926 |(% style="width:366px" %)(((
1927 **TimeRange**
1928
1929 (YYYY-MM-DD(Thh:mm:ss)?/)
1930 )))|(% style="width:284px" %)**time**
1931 |(% style="width:366px" %)(((
1932 **Month**
1933 (MM; speicifies a month independent of a year; e.g. February is black history month in the United States)
1934 )))|(% style="width:284px" %)**string**
1935 |(% style="width:366px" %)(((
1936 **MonthDay**
1937 (MM-DD; specifies a day within a month independent of a year; e.g. Christmas is December 25^^th^^; used to specify reporting year start day)
1938 )))|(% style="width:284px" %)**string**
1939 |(% style="width:366px" %)(((
1940 **Day**
1941 (-DD; specifies a day independent of a month or year; e.g. the 15^^th^^ is payday)
1942 )))|(% style="width:284px" %)**string**
1943 |(% style="width:366px" %)(((
1944 **Time**
1945 (hh:mm:ss; time independent of a date; e.g. coffee break is at 10:00 AM)
1946 )))|(% style="width:284px" %)**string**
1947 |(% style="width:366px" %)(((
1948 **Duration**
1949 (corresponds to XML Schema xs:duration datatype)
1950 )))|(% style="width:284px" %)**duration**
1951 |(% style="width:366px" %)XHTML|(% style="width:284px" %)Metadata type – not applicable
1952 |(% style="width:366px" %)KeyValues|(% style="width:284px" %)Metadata type – not applicable
1953 |(% style="width:366px" %)IdentifiableReference|(% style="width:284px" %)Metadata type – not applicable
1954 |(% style="width:366px" %)DataSetReference|(% style="width:284px" %)Metadata type – not applicable
1955 |(% style="width:366px" %)AttachmentConstraintReference|(% style="width:284px" %)Metadata type – not applicable
1956
1957 **Figure 14 – Mappings from SDMX data types to VTL Basic Scalar Types**
1958
1959 When [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] takes in input [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]], it is assumed that a type conversion according to the table above always happens. In case a different [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] basic scalar type is desired, it can be achieved in the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] program taking in input the default [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] basic scalar type above and applying to it the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] type conversion features (see the implicit and explicit type conversion and the “cast” operator in the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Reference Manual).
1960
1961 === 10.4.4 Mapping VTL basic scalar types to SDMX data types ===
1962
1963 The following table describes the default conversion from the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] basic scalar types to the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] data types .
1964
1965 (% style="width:923.835px" %)
1966 |(% style="width:191px" %)**VTL basic scalar type**|(% style="width:419px" %)**Default SDMX data type (BasicComponentDataType)**|(% style="width:311px" %)**Default output format**
1967 |(% style="width:191px" %)**String**|(% style="width:419px" %)**String **|(% style="width:311px" %)Like XML (xs:string)
1968 |(% style="width:191px" %)**Number**|(% style="width:419px" %)**Float **|(% style="width:311px" %)Like XML (xs:float)
1969 |(% style="width:191px" %)**Integer**|(% style="width:419px" %)**Integer **|(% style="width:311px" %)Like XML (xs:int)
1970 |(% style="width:191px" %)**Date**|(% style="width:419px" %)**DateTime**|(% style="width:311px" %)YYYY-MM-DDT00:00:00Z
1971 |(% style="width:191px" %)**Time**|(% style="width:419px" %)**StandardTimePeriod**|(% style="width:311px" %)/ (as defined above)
1972 |(% style="width:191px" %)**time_period**|(% style="width:419px" %)(((
1973 **ReportingTimePeriod
1974 (StandardReportingPeriod)**
1975 )))|(% style="width:311px" %)(((
1976 YYYY-Pppp
1977 (according to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] )
1978 )))
1979 |(% style="width:191px" %)**Duration**|(% style="width:419px" %)**Duration **|(% style="width:311px" %)(((
1980 Like XML (xs:duration)
1981 PnYnMnDTnHnMnS
1982 )))
1983 |(% style="width:191px" %)**Boolean**|(% style="width:419px" %)**Boolean **|(% style="width:311px" %)(((
1984 Like XML (xs:boolean) with the values “true” or “false”
1985 )))
1986
1987 **Figure 14 – Mappings from [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] data types to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Basic Scalar Types**
1988
1989 In case a different default conversion is desired, it can be achieved through the CustomTypeScheme and CustomType [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] (see also the section Transformations and Expressions of the [[SDMX information model>>doc:sdmx:Glossary.SDMX Information Model.WebHome]]).
1990
1991 The custom output formats can be specified by means of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] formatting mask described in the section “Type Conversion and Formatting Mask” of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Reference Manual. Such a section describes the masks for the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] basic scalar types “number”, “integer”, “date”, “time”, “time_period” and “duration” and gives examples. As for the types “string” and “boolean” the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] conventions are extended with some other special characters as described in the following table.
1992
1993 (% style="width:671.835px" %)
1994 |(% colspan="2" style="width:669px" %)**VTL special characters for the formatting masks**
1995 |(% colspan="2" style="width:669px" %)** **
1996 |(% colspan="2" style="width:669px" %)**Number **
1997 |(% style="width:141px" %)D|(% style="width:528px" %)one numeric digit (if the scientific notation is adopted, D is only for the mantissa)
1998 |(% style="width:141px" %)E|(% style="width:528px" %)one numeric digit (for the exponent of the scientific notation)
1999 |(% style="width:141px" %).(dot)|(% style="width:528px" %)possible separator between the integer and the [[decimal>>doc:sdmx:Glossary.Decimals.WebHome]] parts.
2000 |(% style="width:141px" %),(comma)|(% style="width:528px" %)possible separator between the integer and the [[decimal>>doc:sdmx:Glossary.Decimals.WebHome]] parts.
2001 |(% style="width:141px" %) |(% style="width:528px" %)
2002 |(% colspan="2" style="width:669px" %)**Time and duration**
2003 |(% style="width:141px" %)C |(% style="width:528px" %)century
2004 |(% style="width:141px" %)Y|(% style="width:528px" %)year
2005 |(% style="width:141px" %)S|(% style="width:528px" %)semester
2006 |(% style="width:141px" %)Q|(% style="width:528px" %)quarter
2007 |(% style="width:141px" %)M|(% style="width:528px" %)month
2008 |(% style="width:141px" %)W|(% style="width:528px" %)week
2009 |(% style="width:141px" %)D|(% style="width:528px" %)day
2010 |(% style="width:141px" %)h |(% style="width:528px" %)hour digit (by default on 24 hours)
2011 |(% style="width:141px" %)M|(% style="width:528px" %)minute
2012 |(% style="width:141px" %)S|(% style="width:528px" %)second
2013 |(% style="width:141px" %)D|(% style="width:528px" %)[[decimal>>doc:sdmx:Glossary.Decimals.WebHome]] of second
2014 |(% style="width:141px" %)P|(% style="width:528px" %)period indicator (representation in one digit for the duration)
2015 |(% style="width:141px" %)P|(% style="width:528px" %)number of the periods specified in the period indicator
2016 |(% style="width:141px" %)AM/PM |(% style="width:528px" %)indicator of AM / PM (e.g. am/pm for “am” or “pm”)
2017 |(% style="width:141px" %)MONTH|(% style="width:528px" %)uppercase textual representation of the month (e.g., JANUARY for January)
2018 |(% style="width:141px" %)DAY|(% style="width:528px" %)uppercase textual representation of the day (e.g., MONDAY for Monday)
2019 |(% style="width:141px" %)Month|(% style="width:528px" %)lowercase textual representation of the month (e.g., january)
2020 |(% style="width:141px" %)Day|(% style="width:528px" %)lowercase textual representation of the month (e.g., monday)
2021 |(% style="width:141px" %)Month|(% style="width:528px" %)First character uppercase, then lowercase textual representation of the month (e.g., January)
2022 |(% style="width:141px" %)Day|(% style="width:528px" %)First character uppercase, then lowercase textual [[representation>>doc:sdmx:Glossary.Representation.WebHome]] of the day using (e.g. Monday)
2023 |(% style="width:141px" %) |(% style="width:528px" %)
2024 |(% colspan="2" style="width:669px" %)**String**
2025 |(% style="width:141px" %)X|(% style="width:528px" %)any string character
2026 |(% style="width:141px" %)Z|(% style="width:528px" %)any string character from “A” to “z”
2027 |(% style="width:141px" %)9|(% style="width:528px" %)any string character from “0” to “9”
2028 |(% style="width:141px" %) |(% style="width:528px" %)
2029 |(% colspan="2" style="width:669px" %)**Boolean **
2030 |(% style="width:141px" %)B|(% style="width:528px" %)Boolean using “true” for True and “false” for False
2031 |(% style="width:141px" %)1|(% style="width:528px" %)Boolean using “1” for True and “0” for False
2032 |(% style="width:141px" %)0|(% style="width:528px" %)Boolean using “0” for True and “1” for False
2033 |(% style="width:141px" %) |(% style="width:528px" %)
2034 |(% colspan="2" style="width:669px" %)Other qualifiers
2035 |(% style="width:141px" %)*|(% style="width:528px" %)an arbitrary number of digits (of the preceding type)
2036 |(% style="width:141px" %)+|(% style="width:528px" %)at least one digit (of the preceding type)
2037 |(% style="width:141px" %)( )|(% style="width:528px" %)optional digits (specified within the brackets)
2038 |(% style="width:141px" %)\|(% style="width:528px" %)prefix for the special characters that must appear in the mask
2039 |(% style="width:141px" %)N|(% style="width:528px" %)fixed number of digits used in the preceding textual [[representation>>doc:sdmx:Glossary.Representation.WebHome]] of the month or the day
2040 |(% style="width:141px" %) |(% style="width:528px" %)
2041
2042 The default conversion, either standard or customized, can be used to deduce automatically the [[representation>>doc:sdmx:Glossary.Representation.WebHome]] of the [[components>>doc:sdmx:Glossary.Component.WebHome]] of the result of a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] transformation. In alternative, the [[representation>>doc:sdmx:Glossary.Representation.WebHome]] of the resulting [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]] can be given explicitly by providing its DataStructureDefinition. In other words, the [[representation>>doc:sdmx:Glossary.Representation.WebHome]] specified in the [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]], if available, overrides any default conversion[[(% class="wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink wikiinternallink" %)^^~[43~]^^>>path:#_ftn43]](%%).
2043
2044 === 10.4.5 Null Values ===
2045
2046 In the conversions from [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] it is assumed by default that a missing value in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] becomes a NULL in [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]]. After the conversion, the NULLs can be manipulated through the proper [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] operators.
2047
2048 On the other side, the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] programs can produce in output NULL values for [[Measures>>doc:sdmx:Glossary.Measure.WebHome]] and [[Attributes>>doc:sdmx:Glossary.Attribute.WebHome]] (Null values are not allowed in the Identifiers). In the conversion from [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]], it is assumed that a NULL in [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] becomes a missing value in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]].
2049
2050 In the conversion from [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]], the default assumption can be overridden, separately for each [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] basic scalar type, by specifying which the value that represents the NULL in [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] is. This can be specified in the [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] “nullValue” of the CustomType [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] (see also the section Transformations and Expressions of the [[SDMX information model>>doc:sdmx:Glossary.SDMX Information Model.WebHome]]). A CustomType belongs to a CustomTypeScheme, which can be referenced by one or more TransformationScheme (i.e. [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] programs). The overriding assumption is applied for all the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Dataflows>>doc:sdmx:Glossary.Dataflow.WebHome]] calculated in the TransformationScheme.
2051
2052 === 10.4.6 Format of the literals used in VTL transformations ===
2053
2054 The [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] programs can contain literals, i.e. specific values of certain data types written directly in the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] definitions or expressions. The [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] does not prescribe a specific format for the literals and leave the specific [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] systems and the definers of [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] transformations free of using their preferred formats.
2055
2056 Given this discretion, it is essential to know which are the external [[representations>>doc:sdmx:Glossary.Representation.WebHome]] adopted for the literals in a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] program, in order to interpret them correctly. For example, if the external format for the dates is YYYY-MM-DD the date literal 201001-02 has the meaning of 2^^nd^^ January 2010, instead if the external format for the dates is YYYY-DD-MM the same literal has the meaning of 1^^st^^ February 2010.
2057
2058 Hereinafter, i.e. in the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] implementation of the [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]], it is assumed that the literals are expressed according to the “default output format” of the table of the previous paragraph (“Mapping [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] basic scalar types to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] data types”) unless otherwise specified.
2059
2060 A different format can be specified in the [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] “vtlLiteralFormat” of the CustomType [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] (see also the section Transformations and Expressions of the [[SDMX information model>>doc:sdmx:Glossary.SDMX Information Model.WebHome]]).
2061
2062 Like in the case of the conversion of NULLs described in the previous paragraph, the overriding assumption is applied, for a certain [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] basic scalar type, if a value is found for the vtlLiteralFormat [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] of the CustomType of such [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] basic scalar type. The overriding assumption is applied for all the literals of a related [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] TransformationScheme.
2063
2064 In case a literal is operand of a [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Cast operation, the format specified in the Cast overrides all the possible otherwise specified formats.
2065
2066 = 11 Annex I: How to eliminate extra element in the .NET SDMX Web Service =
2067
2068 == 11.1 Problem statement ==
2069
2070 For implementing an [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] compliant Web Service the standardised WSDL file should be used that describes the expected request/response structure. The request message of the operation contains a wrapper element (e.g. “GetGenericData”) that wraps a tag called “GenericDataQuery”, which is the actual [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] query XML message that contains the query to be processed by the Web Service. In the same way the response is formulated in a wrapper element “GetGenericDataResponse”.
2071
2072 As defined in the SOAP specification, the root element of a SOAP message is the Envelope, which contains an optional Header and a mandatory Body. These are illustrated below along with the Body contents according to the WSDL:
2073
2074 (% contenteditable="false" tabindex="-1" %)[[image:1747854006117-843.png||data-widget="image"]]
2075
2076 The problem that initiated the present analysis refers to the difference in the way SOAP requests are when trying to implement the aforementioned Web Service in .NET framework.
2077
2078 Building such a Web Service using the .NET framework is done by exposing a method (i.e. the getGenericData in the example) with an XML document argument (lets name it “Query”). **The difference that appears in Microsoft .Net implementations is that there is a need for an extra XML container around the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] GenericDataQuery.** This is the expected behavior since the framework is let to publish automatically the Web Service as a remote procedure call, thus wraps each parameter into an extra element. The .NET request is illustrated below:
2079
2080 (% contenteditable="false" tabindex="-1" %)[[image:1747854039499-443.png||data-widget="image"]]
2081
2082 (% contenteditable="false" tabindex="-1" %)[[image:1747854067769-691.png||data-widget="image"]]
2083
2084 Furthermore this extra element is also inserted in the automatically generated WSDL from the framework. Therefore this particularity requires custom clients for the .NET Web Services that is not an interoperable solution.
2085
2086 == 11.2 Solution ==
2087
2088 The solution proposed for conforming the .NET implementation to the envisioned SOAP requests has to do with the manual intervention to the serialisation and deserialisation of the XML payloads. Since it is a Web Service of already prepared XML messages requests/responses this is the indicate way so as to have full control on the XML messages. This is the way the Java implementation (using Apache Axis) of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] Web Service has adopted.
2089
2090 As regards the .NET platform this is related with the usage of **XmlAnyElement** parameter for the .NET web methods.
2091
2092 Web methods use XmlSerializer in the .NET Framework to invoke methods and build the response.
2093
2094 (% contenteditable="false" tabindex="-1" %)[[image:1747836776717-914.jpeg||data-widget="image"]]
2095
2096 The XML is passed to the XmlSerializer to de-serialize it into the instances of classes in managed [[code>>doc:sdmx:Glossary.Code.WebHome]] that (% style="color:#e74c3c" %)map(%%) to the input parameters for the Web method. Likewise, the output parameters and return values of the Web method are serialized into XML in order to create the body of the SOAP response message.
2097
2098 In case the developer wants more control over the serialization and de-serialization process a solution is represented by the usage of **XmlElement** parameters. This offers the opportunity of validating the XML against a schema before de-serializing it, avoiding de-serialization in the first place, analyzing the XML to determine how you want to de-serialize it, or using the many powerful XML APIs that are available to deal with the XML directly. This also gives the developer the control to handle errors in a particular way instead of using the faults that the XmlSerializer might generate under the covers.
2099
2100 In order to control the de-serialization process of the XmlSerializer for a Web method, **XmlAnyElement** is a simple solution to use.
2101
2102 To understand how the **XmlAnyElement** [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] works we present the following two web methods:
2103
2104 (% contenteditable="false" tabindex="-1" %)[[image:1747854096778-844.png||data-widget="image"]]
2105
2106 In this method the **input** parameter is decorated with the **XmlAnyElement** parameter. This is a hint that this parameter will be de-serialized from an **xsd:any** element. Since the [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] is not passed any parameters, it means that the entire XML element for this parameter in the SOAP message will be in the Infoset that is represented by this **XmlElement** parameter.
2107
2108 (% contenteditable="false" tabindex="-1" %)[[image:1747854127303-270.png||data-widget="image"]]
2109
2110 The difference between the two is that for the first method, **SubmitXml**, the XmlSerializer will expect an element named **input** to be an immediate child of the **SubmitXml** element in the SOAP body. The second method, **SubmitXmlAny**, will not care what the name of the child of the **SubmitXmlAny** element is. It will plug whatever XML is included into the input parameter. The message style from ASP.NET Help for the two methods is shown below. First we look at the message for the method without the **XmlAnyElement** [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]].
2111
2112 (% contenteditable="false" tabindex="-1" %)[[image:1747854163928-581.png||data-widget="image"]]
2113
2114 Now we look at the message for the method that uses the **XmlAnyElement** [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]].
2115
2116 (% contenteditable="false" tabindex="-1" %)[[image:1747854190641-364.png||data-widget="image"]]
2117
2118 (% contenteditable="false" tabindex="-1" %)[[image:1747854236732-512.png||data-widget="image"]]
2119
2120 The method decorated with the **XmlAnyElement** [[attribute>>doc:sdmx:Glossary.Attribute.WebHome]] has one fewer wrapping elements. Only an element with the name of the method wraps what is passed to the **input** parameter.
2121
2122 For more information please consult: [[http:~~/~~/msdn.microsoft.com/en-us/library/aa480498.aspx>>http://msdn.microsoft.com/en-us/library/aa480498.aspx]]
2123
2124 Furthermore at this point the problem with the different requests has been solved. However there is still the difference in the produced WSDL that has to be taken care. The automatic generated WSDL now doesn’t insert the extra element, but defines the content of the operation wrapper element as “xsd:any” type.
2125
2126 (% contenteditable="false" tabindex="-1" %)[[image:1747854286398-614.png||data-widget="image"]]
2127
2128 Without a common WSDL still the solution doesn’t enforce interoperability. In order to
2129
2130 “fix” the WSDL, there two approaches. The first is to intervene in the generation process. This is a complicated approach, compared to the second approach, which overrides the generation process and returns the envisioned WSDL for the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] Web Service.
2131
2132 This is done by redirecting the request to the “/Service?WSDL” to the envisioned WSDL stored locally into the application. To do this, from the project add a “Global Application Class” item (.asax file) and override the request in the “Application_BeginRequest” method. This is demonstrated in detail in the next section.
2133
2134 This approach has the disadvantage that for each deployment the WSDL end point has to be changed to reflect the current URL. However this inconvenience can be easily eliminated if a developer implements a simple rewriting module for changing the end point to the one of the current deployment.
2135
2136 == 11.3 Applying the solution ==
2137
2138 In the context of the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] Web Service, applying the above solution translates into the following:
2139
2140 (% contenteditable="false" tabindex="-1" %)[[image:1747854385465-132.png||data-widget="image"]]
2141
2142 The SOAP request/response will then be as follows:
2143
2144 **GenericData Request**
2145
2146 (% contenteditable="false" tabindex="-1" %)[[image:1747854406014-782.png||data-widget="image"]]
2147
2148 **GenericData Response**
2149
2150 (% contenteditable="false" tabindex="-1" %)[[image:1747854424488-855.png||data-widget="image"]]
2151
2152 For overriding the automatically produced WSDL, in the solution explorer right click the project and select “Add” -> “New item…”. Then select the “Global Application Class”. This will create “.asax” class file in which the following [[code>>doc:sdmx:Glossary.Code.WebHome]] should replace the existing empty method:
2153
2154 (% contenteditable="false" tabindex="-1" %)[[image:1747854453895-524.png||data-widget="image"]]
2155
2156 (% contenteditable="false" tabindex="-1" %)[[image:1747854476631-125.png||data-widget="image"]]
2157
2158 The SDMX_WSDL.wsdl should reside in the in the root directory of the application. After applying this solution the returned WSDL is the envisioned. Thus in the request message definition contains:
2159
2160 (% contenteditable="false" tabindex="-1" %)[[image:1747854493363-776.png||data-widget="image"]]
2161
2162 ----
2163
2164 [[~[2~]>>path:#_ftnref2]]
2165
2166 [[~[3~]>>path:#_ftnref3]] The rules for adding durations to a date time are described in the W3C XML Schema specification. See [[http:~~/~~/www.w3.org/TR/xmlschema>>url:http://www.w3.org/TR/xmlschema-2/#adding-durations-to-dateTimes]][[->>url:http://www.w3.org/TR/xmlschema-2/#adding-durations-to-dateTimes]][[2/#adding>>url:http://www.w3.org/TR/xmlschema-2/#adding-durations-to-dateTimes]][[->>url:http://www.w3.org/TR/xmlschema-2/#adding-durations-to-dateTimes]][[durations>>url:http://www.w3.org/TR/xmlschema-2/#adding-durations-to-dateTimes]][[->>url:http://www.w3.org/TR/xmlschema-2/#adding-durations-to-dateTimes]][[to>>url:http://www.w3.org/TR/xmlschema-2/#adding-durations-to-dateTimes]][[dateTimes>>url:http://www.w3.org/TR/xmlschema-2/#adding-durations-to-dateTimes]][[ >>url:http://www.w3.org/TR/xmlschema-2/#adding-durations-to-dateTimes]]for further details.
2167
2168 [[~[4~]>>path:#_ftnref4]] The Validation and Transformation Language is a standard language designed and published under the SDMX initiative. VTL is described in the VTL User and Reference Guides available on the SDMX website [[https:~~/~~/sdmx.org>>url:https://sdmx.org/]][[.>>url:https://sdmx.org/]]
2169
2170 [[~[5~]>>path:#_ftnref5]] See also the section “VTL-DL Rulesets” in the VTL Reference Manual.
2171
2172 [[~[6~]>>path:#_ftnref6]] The VTLMapping are used also for User Defined Operators (UDO). Although UDOperators are envisaged to be defined on generic operands, so that the specific artefacts to be manipulated are passed as parameters at their invocation, it is also possible that an UDOperator invokes directly some specific SDMX artefacts. These SDMX artefacts have to be mapped to the corresponding aliases used in the definition of the UDO through the VtlMappingScheme and VtlMapping classes as well.
2173
2174 [[~[7~]>>path:#_ftnref7]] For a complete description of the structure of the URN see the SDMX 2.1 Standards - Section 5 - Registry Specifications, paragraph 6.2.2 (“Universal Resource Name (URN)”).
2175
2176 [[~[8~]>>path:#_ftnref8]] The container-object-id can repeat and may not be present.
2177
2178 [[~[9~]>>path:#_ftnref9]] i.e., the artefact belongs to a maintainable class
2179
2180 [[~[10~]>>path:#_ftnref10]] Since these references to SDMX objects include non-permitted characters as per the VTL ID notation, they need to be included between single quotes, according to the VTL rules for irregular names.
2181
2182 [[~[11~]>>path:#_ftnref11]] For the syntax of the VTL operators see the VTL Reference Manual
2183
2184 [[~[12~]>>path:#_ftnref12]] In case the invoked artefact is a VTL component, which can be invoked only within the invocation of a
2185
2186 VTL data set (SDMX dataflow), the specific SDMX class-name (e.g. Dimension, MeasureDimension, TimeDimension, PrimaryMeasure or DataAttribute) can be deduced from the data structure of the SDMX Dataflow which the component belongs to.
2187
2188 [[~[13~]>>path:#_ftnref13]] If the Agency is composite (for example AgencyA.Dept1.Unit2), the agency is considered different even if only part of the composite name is different (for example AgencyA.Dept1.Unit3 is a different Agency than the previous one). Moreover the agency-id cannot be omitted in part (i.e., if a TransformationScheme owned by AgencyA.Dept1.Unit2 references an artefact coming from AgencyA.Dept1.Unit3, the specification of the agency-id becomes mandatory and must be complete, without omitting the possibly equal parts like AgencyA.Dept1)
2189
2190 [[~[14~]>>path:#_ftnref14]] Single quotes are needed because this reference is not a VTL regular name.
2191
2192 [[~[15~]>>path:#_ftnref15]] Single quotes are not needed in this case because CL_FREQ is a VTL regular name.
2193
2194 [[~[16~]>>path:#_ftnref16]] The result DFR(1.0) is be equal to DF1(1.0) save that the component SECTOR is called SEC
2195
2196 [[~[17~]>>path:#_ftnref17]] Rulesets of this kind cannot be reused when the referenced Concept has a different representation.
2197
2198 [[~[18~]>>path:#_ftnref18]] See also the section “VTL-DL Rulesets” in the VTL Reference Manual.
2199
2200 [[~[19~]>>path:#_ftnref19]] If a calculated artefact is persistent, it needs a persistent definition, i.e. a SDMX definition in a SDMX environment. Also possible calculated artefact that are not persistent may require a SDMX definition, for example when the result of a non-persistent calculation is disseminated through SDMX tools (like an inquiry tool).
2201
2202 [[~[20~]>>path:#_ftnref20]] See the VTL 2.0 User Manual
2203
2204 [[~[21~]>>path:#_ftnref21]] See the SDMX 2.1 Section 2 – Information Model
2205
2206 [[~[22~]>>path:#_ftnref22]] Besides the mapping between one SDMX Dataflow and one VTL Data Set, it is also possible to map distinct parts of a SDMX Dataflow to different VTL Data Set, as explained in a following paragraph.
2207
2208 [[~[23~]>>path:#_ftnref23]] The SDMX community is evaluating the opportunity of allowing more than one measure component in a DataStructureDefinition in the next SDMX major version.
2209
2210 [[~[24~]>>path:#_ftnref24]] If future SDMX major versions will allow multi-measures data structures, this method is expected to become applicable even if the VTL data structure has more than one measure
2211
2212 [[~[25~]>>path:#_ftnref25]] The kind of mapping explained here works in combination with a SDMX specific naming convention that requires pre-processing before parsing the VTL expressions. As highlighted below, the identifiers of the VTL datasets are a shortcut of some specific VTL operators applied to the SDMX Dataflows. This is not safe to use outside an SDMX context, as the naming convention may have no meaning there.
2213
2214 [[~[26~]>>path:#_ftnref26]] A typical example of this kind is the validation, and more in general the manipulation, of individual time series belonging to the same Dataflow, identifiable through the dimension components of the Dataflow except the time Dimension. The coding of these kind of operations might be simplified by mapping distinct time series (i.e. different parts of a SDMX Dataflow) to distinct VTL data sets.
2215
2216 [[~[27~]>>path:#_ftnref27]] Please note that this kind of mapping is only an option at disposal of the definer of VTL Transformations; in fact it remains always possible to manipulate the needed parts of SDMX Dataflows by means of VTL operators (e.g. “sub”, “filter”, “calc”, “union” …), maintaining a mapping one-to-one between SDMX Dataflows and VTL datasets.
2217
2218 [[~[28~]>>path:#_ftnref28]] This definition is made through the ToVtlSubspace and ToVtlSpaceKey classes and/or the FromVtlSuperspace and FromVtlSpaceKey classes, depending on the direction of the mapping (“key” means “dimension”). The mapping of Dataflow subsets can be applied independently in the two directions, also according to different Dimensions. When no Dimension is declared for a given direction, it is assumed that the option of mapping different parts of a SDMX Dataflow to different VTL datasets is not used.
2219
2220 [[~[29~]>>path:#_ftnref29]] As a consequence of this formalism, a slash in the name of the VTL dataset assumes the specific meaning of separator between the name of the Dataflow and the values of some of its Dimensions.
2221
2222 [[~[30~]>>path:#_ftnref30]] This is the order in which the dimensions are defined in the ToVtlSpaceKey class or in the FromVtlSpaceKey class, depending on the direction of the mapping.
2223
2224 [[~[31~]>>path:#_ftnref31]] It should be remembered that, according to the VTL consistency rules, a given VTL dataset cannot be the result of more than one VTL transformation.
2225
2226 [[~[32~]>>path:#_ftnref32]] If these dimensions would not be dropped, taking into account that the typical binary VTL operations at dataset level (+, -, *, / and so on) are executed on the observations having matching identifiers, the VTL datasets resulting from this kind of mapping would have non-matching values for the mapping dimensions (e.g. POPULATION and COUNTRY), therefore it would not be possible to compose the resulting VTL datasets one another (e.g. it would not be possible to calculate the population ratio between USA and CANADA). ^^ ^^
2227
2228 [[~[33~]>>path:#_ftnref33]] In case the ordered concatenation notation is used, the VTL Transformation described above, e.g.
2229
2230 ‘DF1(1.0)/POPULATION.USA’ := DF1(1.0) [ sub INDICATOR=“POPULATION”, COUNTRY=“USA”], is implicitly executed and, in order to test the overall compliance of the VTL program to the VTL consistency rules, it has to be considered as part of the VTL program even if it is not explicitly coded.
2231
2232 [[~[34~]>>path:#_ftnref34]] If the whole DF2(1.0) is calculated by means of just one VTL transformation, then the mapping between the SDMX dataflow and the corresponding VTL dataset is one-to-one and this kind of mapping (one SDMX Dataflow to many VTL datasets) does not apply..
2233
2234 [[~[35~]>>path:#_ftnref35]] This is possible as each VTL dataset corresponds to one particular combination of values of INDICATOR and COUNTRY
2235
2236 [[~[36~]>>path:#_ftnref36]] The mapping dimensions are defined as FromVtlSpaceKeys of the FromVtlSuperSpace of the ,,VtlDataflowMapping,, relevant to DF2(1.0)
2237
2238 [[~[37~]>>path:#_ftnref37]] the symbol of the VTL persistent assignment is used (<-)
2239
2240 [[~[38~]>>path:#_ftnref38]] The result is persistent in this example but it can be also non persistent if needed.
2241
2242 [[~[39~]>>path:#_ftnref39]] In case the ordered concatenation notation from VTL to SDMX is used, the set of transformations described above is implicitly performed; therefore, in order to test the overall compliance of the VTL program to the VTL consistency rules, these implicit transformations have to be considered as part of the VTL program even if they are not explicitly coded.
2243
2244 [[~[40~]>>path:#_ftnref40]] Through SDMX Constraints, it is possible to specify the values that a Component of a Dataflow can assume.
2245
2246 [[~[41~]>>path:#_ftnref41]] By using represented variables, VTL can assume that data structures having the same variables as identifiers can be composed one another because the correspondent values can match.
2247
2248 [[~[42~]>>path:#_ftnref42]] A Concept becomes a Component in a DataStructureDefinition, and Components can have different LocalRepresentations in different DataStructureDefinitions, also overriding the (possible) base representation of the Concept.
2249
2250 [[~[43~]>>path:#_ftnref43]] The representation given in the DSD should obviously be compatible with the VTL data type.
2251
2252 (% contenteditable="false" tabindex="-1" %)
2253 (((
2254 (% class="macro" data-macro="startmacro:putFootnotes|-|" data-widget="xwiki-macro" %)
2255 (((
2256 (% class="macro-placeholder hidden" %)
2257 (((
2258 macro:putFootnotes
2259 )))
2260
2261 (% class="footnotes" %)
2262 1. [[^>>doc:null||anchor="x_footnote_ref_1" id="x_footnote_1" class="footnoteBackRef"]] The seconds can be reported fractionally
2263 1. [[^>>doc:null||anchor="x_footnote_ref_2" id="x_footnote_2" class="footnoteBackRef"]] ISO 8601 defines alternative definitions for the first week, all of which produce equivalent results. Any of these definitions could be substituted so long as they are in relation to the reporting year start day.
2264 1. [[^>>doc:null||anchor="x_footnote_ref_3" id="x_footnote_3" class="footnoteBackRef"]] 2010-Q3 (with a reporting year start day of --01-01) starts on 2010-07-01. This is day 4 of week 26, therefore the first week matched is week 27.--
2265 1. [[^>>doc:null||anchor="x_footnote_ref_4" id="x_footnote_4" class="footnoteBackRef"]] 2010-Q3 (with a reporting year start day of --07-01) starts on 2011-01-01. This is day 6 of week 27, therefore the first week matched is week 28.--
2266 )))
2267 )))