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1 +Artefact|Metadata set|Reference metadata|SDMX Information Model|SDMX Technical Specification|SDMX-JSON|SDMX-ML|Statistical data and metadata exchange|Statistical subject-matter domain|Structural metadata|Validation and transformation language
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11 11  
12 12  = 1 Introduction =
13 13  
14 -The Statistical Data and Metadata Exchange (SDMX) initiative (https:~/~/www.sdmx.org) sets 3 standards that can facilitate the exchange of statistical data and metadata using modern 4 information technology.
14 +The [[Statistical Data and Metadata Exchange>>doc:xwiki:Glossary.Statistical data and metadata exchange.WebHome]] ([[SDMX>>doc:xwiki:Glossary.Statistical data and metadata exchange.WebHome]]) initiative (https:~/~/www.[[sdmx>>doc:xwiki:Glossary.Statistical data and metadata exchange.WebHome]].org) sets 3 standards that can facilitate the exchange of statistical data and metadata using modern 4 information technology.
15 15  
16 -The SDMX Technical Specifications are organised into several discrete sections.
16 +The [[SDMX Technical Specifications>>doc:xwiki:Glossary.SDMX Technical Specification.WebHome]] are organised into several discrete sections.
17 17  
18 -The following are published on the SDMX website ([[__https:~~/~~/www.sdmx.org__>>https://https:www.sdmx.org]]).
18 +The following are published on the [[SDMX>>doc:xwiki:Glossary.Statistical data and metadata exchange.WebHome]] website
19 19  
20 +([[__https:~~/~~/www.sdmx.org__>>https://https:www.sdmx.org]]).
21 +
20 20  **Section 1** **Framework for SDMX Technical Standards** – this document providing an introduction to the technical standards.
21 21  
22 -**Section 2** **SDMX Information Model** - the SDMX information model is a standardised object model for modelling statistical domains centring on the structure of their data and metadata sets, the coding schemes used for classification, and the rules for controlling the exchange of data and metadata between organisations. This document provides a UML specification with supporting narrative.
24 +**Section 2** **SDMX Information Model** -
23 23  
24 -**Section 5** **SDMX Registry Specification** – an SDMX ‘registry’ acts as a repository for structural metadata and provisioning information, and a registry of data and metadata sources. This document sets out the specification.
26 +the [[SDMX information model>>doc:xwiki:Glossary.SDMX Information Model.WebHome]] is a standardised object model for modelling [[statistical domains>>doc:xwiki:Glossary.Statistical subject-matter domain.WebHome]] centring on the structure of their data and [[metadata sets>>doc:xwiki:Glossary.Metadata set.WebHome]], the coding schemes used for classification, and the rules for controlling the exchange of data and metadata between organisations. This document provides a UML specification with supporting narrative.
25 25  
26 -**Section 6** **SDMX Technical Notes** – detailed technical guidance for implementors of the SDMX standard.
28 +**Section 5** **SDMX Registry Specification** – an [[SDMX>>doc:xwiki:Glossary.Statistical data and metadata exchange.WebHome]] ‘registry’ acts as a repository for [[structural metadata>>doc:xwiki:Glossary.Structural metadata.WebHome]] and provisioning information, and a registry of data and metadata sources. This document sets out the specification.
27 27  
28 -The following are published on the GitHub repository of the SDMX Standards Technical Working Group ( __[[https:~~/~~/github.com/sdmx-twg>>https://github.com/sdmx-twg]]) :__
30 +**Section 6** **SDMX Technical Notes** – detailed technical guidance for implementors of the [[SDMX>>doc:xwiki:Glossary.Statistical data and metadata exchange.WebHome]] standard.
29 29  
30 -=== sdmx-twg/sdmx-rest – REST API ===
32 +The following are published on the GitHub repository of the [[SDMX>>doc:xwiki:Glossary.Statistical data and metadata exchange.WebHome]] Standards Technical Working Group ([[__https:~~/~~/github.com/sdmx-twg__>>https://https:github.comsdmx-twg]]):
31 31  
32 -Technical specifications for the SDMX RESTful web services application programming interfaces (API).
34 +(% class="wikigeneratedid" id="Hsdmx-twg2Fsdmx-rest2013RESTAPI" %)
35 +**sdmx-twg/sdmx-rest – REST API**
33 33  
34 -=== sdmx-twg/sdmx-ml – SDMX-ML ===
37 +Technical specifications for the [[SDMX>>doc:xwiki:Glossary.Statistical data and metadata exchange.WebHome]] RESTful web services application programming interfaces (API).
35 35  
36 -Technical specifications for the XML transmission format including XSD schemas, documentation and samples for data, structure and reference metadata messages.
39 +(% class="wikigeneratedid" id="Hsdmx-twg2Fsdmx-ml2013SDMX-ML" %)
40 +**sdmx-twg/sdmx-ml – [[SDMX-ML>>doc:xwiki:Glossary.SDMX-ML.WebHome]]**
37 37  
38 -=== sdmx-twg/sdmx-json – SDMX-JSON ===
42 +Technical specifications for the XML transmission format including XSD schemas, documentation and samples for data, structure and [[reference metadata>>doc:xwiki:Glossary.Reference metadata.WebHome]] messages.
39 39  
40 -Technical specifications for the JSON transmission format including documentation, schemas and samples for data, structure and reference metadata messages.
44 +(% class="wikigeneratedid" id="Hsdmx-twg2Fsdmx-json2013SDMX-JSON" %)
45 +**sdmx-twg/sdmx-json – [[SDMX-JSON>>doc:xwiki:Glossary.SDMX-JSON.WebHome]]**
41 41  
42 -=== sdmx-twg/sdmx-csv – SDMX-CSV ===
47 +Technical specifications for the JSON transmission format including documentation, schemas and samples for data, structure and [[reference metadata>>doc:xwiki:Glossary.Reference metadata.WebHome]] messages.
43 43  
44 -Technical specifications for the SDMX-CSV transmission format for ‘comma-separated values’ (CSV) data and reference metadata.
49 +(% class="wikigeneratedid" id="Hsdmx-twg2Fsdmx-csv2013SDMX-CSV" %)
50 +**sdmx-twg/sdmx-csv – [[SDMX>>doc:xwiki:Glossary.Statistical data and metadata exchange.WebHome]]-CSV**
45 45  
52 +Technical specifications for the [[SDMX>>doc:xwiki:Glossary.Statistical data and metadata exchange.WebHome]]-CSV transmission format for ‘comma-separated values’ (CSV) data and [[reference metadata>>doc:xwiki:Glossary.Reference metadata.WebHome]].
53 +
46 46  The following sections are obsolete:
47 47  
48 -Section 3 - SDMX-ML - replaced by the sdmx-twg/sdmx-ml GitHub repository
56 +Section 3 - [[SDMX-ML>>doc:xwiki:Glossary.SDMX-ML.WebHome]] - replaced by the [[sdmx>>doc:xwiki:Glossary.Statistical data and metadata exchange.WebHome]]-twg/[[sdmx-ml>>doc:xwiki:Glossary.SDMX-ML.WebHome]] GitHub repository
49 49  
50 -Section 4 - SDMX-EDI
58 +Section 4 - [[SDMX>>doc:xwiki:Glossary.Statistical data and metadata exchange.WebHome]]-EDI
51 51  
52 -Section 7 - API - replaced by the sdmx-twg/sdmx-rest GitHub repository VTL
60 +Section 7 - API - replaced by the [[sdmx>>doc:xwiki:Glossary.Statistical data and metadata exchange.WebHome]]-twg/[[sdmx>>doc:xwiki:Glossary.Statistical data and metadata exchange.WebHome]]-rest GitHub repository [[VTL>>doc:xwiki:Glossary.Validation and transformation language.WebHome]]
53 53  
54 -In July 2020 the SDMX 2.1 specifications were revised to add support for the Validation and Transformation Language (VTL). For 3.0, the VTL specification has been updated to align with changes to the information model and other modifications to the Standard such as the introduction of Semantic Versioning for the versioning of structural metadata artefacts. Section 2 (Information Model) sets out details of the ‘Transformation and Expressions’ package for defining and managing VTL 2.0 programs and Section 6 (Technical Notes) provides detailed guidance on implementing and using VTL with SDMX.
62 +In July 2020 the [[SDMX>>doc:xwiki:Glossary.Statistical data and metadata exchange.WebHome]] 2.1 specifications were revised to add support for the [[Validation and Transformation Language>>doc:xwiki:Glossary.Validation and transformation language.WebHome]] ([[VTL>>doc:xwiki:Glossary.Validation and transformation language.WebHome]]). For 3.0, the [[VTL>>doc:xwiki:Glossary.Validation and transformation language.WebHome]] specification has been updated to align with changes to the information model and other modifications to the Standard such as the introduction of Semantic Versioning for the versioning of [[structural metadata>>doc:xwiki:Glossary.Structural metadata.WebHome]] [[artefacts>>doc:xwiki:Glossary.Artefact.WebHome]]. Section 2 (Information Model) sets out details of the ‘Transformation and Expressions’ package for defining and managing [[VTL>>doc:xwiki:Glossary.Validation and transformation language.WebHome]] 2.0 programs and Section 6 (Technical Notes) provides detailed guidance on implementing and using [[VTL>>doc:xwiki:Glossary.Validation and transformation language.WebHome]] with [[SDMX>>doc:xwiki:Glossary.Statistical data and metadata exchange.WebHome]].
55 55  
56 56  = 2 Change History =
57 57  
58 -The 2.0 version of this standard represented a significant increase in scope, and also provided more complete support in those areas covered in the version 1.0 specification. Version 2.0 of this standard is backward-compatible with version 1.0, so that existing implementations can be easily migrated to conformance with version 2.0.
66 +The 2.0 (% style="color:#2ecc71" %)version(%%) of this standard represented a significant increase in scope, and also provided more complete support in those areas covered in the (% style="color:#2ecc71" %)version(%%) 1.0 specification. (% style="color:#2ecc71" %)Version(%%) 2.0 of this standard is backward-compatible with (% style="color:#2ecc71" %)version(%%) 1.0, so that existing implementations can be easily migrated to conformance with (% style="color:#2ecc71" %)version(%%) 2.0.
59 59  
60 -The 2.1 version of this standard represents a set of changes resulting from several years of implementation experience with the 2.0 standard. The changes do not represent a major increase in scope or functionality, but do correct some bugs, and add functionalities in some cases. Major changes in SDMX-ML include a much stronger alignment of the XML Schemas with the Information Model, to emphasize inheritance and object-oriented features, and increased precision and flexibility in the attachment of metadata reports to specific objects in the SDMX Information Model.
68 +The 2.1 (% style="color:#2ecc71" %)version(%%) of this standard represents a set of changes resulting from several years of implementation experience with the 2.0 standard. The changes do not represent a major increase in scope or functionality, but do correct some bugs, and add functionalities in some cases. Major changes in [[SDMX-ML>>doc:xwiki:Glossary.SDMX-ML.WebHome]] include a much stronger alignment of the XML Schemas with the Information Model, to emphasize inheritance and object-oriented features, and increased precision and flexibility in the attachment of metadata reports to specific objects in the [[SDMX>>doc:xwiki:Glossary.Statistical data and metadata exchange.WebHome]] Information Model.
61 61  
62 -The 3.0 version incorporates new features, improvements and changes arising from the collective knowledge gained from a decade of operating experience with the 2.1 standard. In pursuit of modernisation and simplification, features considered obsolete have been deprecated – in particular the EDI transmission format, the lesser-used XML data messages and the SOAP web services API. Many areas remain backwardly compatible with 2.1, but there are some breaking changes where the information model has been redesigned to better support practical use case. Structure mapping and reference metadata are examples. The opportunity has been taken to revise the RESTful web services API which is also not backwardly compatible, but benefits from a rationalisation and better organisations of resources, and a much richer data query URL syntax.
70 +The 3.0 (% style="color:#2ecc71" %)version(%%) incorporates new features, improvements and changes arising from the collective knowledge gained from a decade of operating experience with the 2.1 standard. In pursuit of modernisation and simplification, features considered obsolete have been deprecated – in particular the EDI transmission format, the lesser-used XML data messages and the SOAP web services API. Many areas remain backwardly compatible with 2.1, but there are some breaking changes where the information model has been redesigned to better support practical use case. Structure mapping and [[reference metadata>>doc:xwiki:Glossary.Reference metadata.WebHome]] are examples. The opportunity has been taken to revise the RESTful web services API which is also not backwardly compatible, but benefits from a rationalisation and better organisations of resources, and a much richer data query URL syntax.
63 63  
64 64  == 2.1 Major Changes from 1.0 to 2.0 ==
65 65  
66 -* **Reference Metadata**: In addition to describing and specifying data structures and formats (along with related structural metadata), the version 2.0 specification also provides for the exchange of metadata which is distinct from the structural metadata in the 1.0 version. This category includes “reference” metadata (regarding data quality, methodology, and similar types – it can be configured by the user to include whatever concepts require reporting); metadata related to data provisioning (release calendar information, description of the data and metadata provided, etc.); and metadata relevant to the exchange of categorization schemes.
74 +* **[[Reference Metadata>>doc:xwiki:Glossary.Reference metadata.WebHome]]**: In addition to describing and specifying data structures and formats (along with related [[structural metadata>>doc:xwiki:Glossary.Structural metadata.WebHome]]), the (% style="color:#2ecc71" %)version(%%) 2.0 specification also provides for the exchange of metadata which is distinct from the [[structural metadata>>doc:xwiki:Glossary.Structural metadata.WebHome]] in the 1.0 (% style="color:#2ecc71" %)version(%%). This [[category>>doc:xwiki:Glossary.Category.WebHome]] includes “reference” metadata (regarding data quality, methodology, and similar types – it can be configured by the user to include whatever (% style="color:#2ecc71" %)concepts(%%) require reporting); metadata related to data provisioning ([[release calendar>>doc:xwiki:Glossary.Release policy - release calendar.WebHome]] information, description of the data and metadata provided, etc.); and metadata relevant to the exchange of categorization schemes.
67 67  * **SDMX Registry**: Provision is made in the 2.0 standard for standard communication with registry services, to support a data-sharing model of statistical exchange. These services include registration of data and metadata, querying of registered data and metadata, and subscription.
68 -* **Structural Metadata**: The support for exchange of statistical data and related structural metadata has been expanded. Some support is provided for qualitative data; data cube structures are described; hierarchical code lists are supported; relationships between data structures can be expressed, providing support for extensibility of data structures; 101 and the description of functional dependencies within cubes are supported.
76 +* **[[Structural Metadata>>doc:xwiki:Glossary.Structural metadata.WebHome]]**: The support for exchange of statistical data and related [[structural metadata>>doc:xwiki:Glossary.Structural metadata.WebHome]] has been expanded. Some support is provided for qualitative data; data cube structures are described; [[hierarchical code lists>>doc:xwiki:Glossary.Hierarchical code list.WebHome]] are supported; relationships between data structures can be expressed, providing support for extensibility of data structures; 101 and the description of functional dependencies within cubes are supported.
69 69  
70 70  == 2.2 Major Changes from 2.0 to 2.1 ==
71 71  
... ... @@ -85,7 +85,8 @@
85 85  
86 86  SDMX version 3.0 introduces new features, improvements and changes to the Standard in the following key areas:
87 87  
88 -===== Information Model =====
96 +(% class="wikigeneratedid" id="HInformationModel" %)
97 +**Information Model**
89 89  
90 90  * Simplification and improvement of the reference metadata model
91 91  * Support for microdata
... ... @@ -95,11 +95,13 @@
95 95  * Improvements to code hierarchies for data discovery
96 96  * Improvements to constraints
97 97  
98 -===== Versioning of Structural Metadata Artefacts =====
107 +(% class="wikigeneratedid" id="HVersioningofStructuralMetadataArtefacts" %)
108 +**Versioning of Structural Metadata Artefacts**
99 99  
100 100  * Adoption of the three-number semantic versioning standard for structural metadata artefacts (__[[https:~~/~~/semver.org>>url:https://semver.org/]])__
101 101  
102 -===== REST Web Services Application Programming Interface (API) =====
112 +(% class="wikigeneratedid" id="HRESTWebServicesApplicationProgrammingInterface28API29" %)
113 +**REST Web Services Application Programming Interface (API)**
103 103  
104 104  * Change to a single ‘structure’ resource for structure queries simplifying the REST API specification by reducing the number of resources to five
105 105  * Improvements to data queries
... ... @@ -106,11 +106,13 @@
106 106  * Improvements to reference metadata queries
107 107  * Support for structural metadata maintenance using HTTP PUT, POST and DELETE verbs
108 108  
109 -===== SOAP Web Services API =====
120 +(% class="wikigeneratedid" id="HSOAPWebServicesAPI" %)
121 +**SOAP Web Services API**
110 110  
111 111  * The SOAP web services API has been deprecated with version 3.0 standardising on REST
112 112  
113 -===== XML, JSON, CSV and EDI Transmission formats =====
125 +(% class="wikigeneratedid" id="HXML2CJSON2CCSVandEDITransmissionformats" %)
126 +**XML, JSON, CSV and EDI Transmission formats**
114 114  
115 115  * The SDMX-ML, SDMX-JSON and SDMX-CSV specifications have been extended and modified where needed to support the new features and changes such as reference metadata and microdata
116 116  * Obsolete SDMX-ML data message variants including Generic, Compact, Utility and Cross-sectional have been deprecated standardising on Structure Specific Data as the sole XML format for data exchange
... ... @@ -222,7 +222,7 @@
222 222  * //**Dataflow Definition:**// In SDMX, data sets are reported or disseminated according to a data flow definition. The data flow definition identifies the data structure definition and may be associated with one or more subject matter domains via a Categorisation (this facilitates the search for data according to organised category schemes). Constraints, in terms of reporting periodicity or sub set of possible keys that are allowed in a data set, may be attached to the data flow definition.
223 223  * //**Metadataflow Definition:**// A metadata flow definition is very similar to a data flow definition, but describes, categorises, and constrains metadata sets.
224 224  * //**Data Provider: **//An organization which produces data is termed a data provider.
225 -* //**Metadata Provider: **//An organization which produces reference metadata is termed a metadata provider.//  //
238 +* //**Metadata Provider: **//An organization which produces reference metadata is termed a metadata provider.
226 226  * //**Provision Agreement (Metadata Provision Agreement):**// The set of information which describes the way in which data sets and metadata sets are provided by a data/metadata provider. A provision agreement can be constrained in much the same way as a data or metadata flow definition. Thus, a data provider can express the fact that it provides a particular data flow covering a specific set of countries and topics, Importantly, the actual source of registered data or metadata is attached to the provision agreement (in terms of a URL). The term “agreement” is used because this information can be understood as the basis of a “service-level agreement”. In SDMX, however, this is informational metadata to support the technical systems, as opposed to any sort of contractual information (which is outside the scope of a technical specification). In version 3.0, metadata provision agreement and data provision agreement are two separate artefacts.
227 227  * //**Constraint:**// Data and Metadata Constraints describe a subset of a data source or metadata source, and may also provide information about scheduled releases of data. They are associated with data / metadata providers, provision agreements, data flows, metadataflows, data structure definitions and metadata structure definitions.
228 228  * //**Structure Map: **//Structure maps describes a mapping between data structure definitions or dataflows for the purpose of transforming a data set into a different structure. The mapping rules are defined using one or more component maps which each map in turn describes how one or more components from the source data 534 structure definition map to one or more components in that of the target. Represent maps act as lookup tables and specific provision is made for mapping dates and times.
... ... @@ -267,10 +267,8 @@
267 267  
268 268  SDMX provides a way of modelling statistical data, and defines the set of metadata constructs used for this purpose. Because SDMX specifies a number of transmission formats for expressing data and structural metadata, the model is used as a mechanism for guaranteeing that transformation between the different formats is lossless. In this sense, all of the formats are syntax-bound expressions of the common information model.
269 269  
270 -SDMX recognizes that statistical data is structured; in SDMX this structure is termed a Data Structure Definition. “Data sets” are made up of one or more lower-level “groups”, based on their degrees of similarity. Each group is in turn comprised of one or more “series” of data. Each series or section has a “key” - values for each of a cluster of concepts, also called
283 +SDMX recognizes that statistical data is structured; in SDMX this structure is termed a Data Structure Definition. “Data sets” are made up of one or more lower-level “groups”, based on their degrees of similarity. Each group is in turn comprised of one or more “series” of data. Each series or section has a “key” - values for each of a cluster of concepts, also called "dimensions" - which identifies it, and one or more “observations”, which typically combine the time of the observation, and the value of the observation (e.g., measurement). Additionally, metadata may be attached at any level of this structure as descriptive “attributes”. Code lists (enumerations) and other patterns for representation of data and metadata are also modelled.
271 271  
272 -"dimensions" - which identifies it, and one or more “observations”, which typically combine the time of the observation, and the value of the observation (e.g., measurement). Additionally, metadata may be attached at any level of this structure as descriptive “attributes”. Code lists (enumerations) and other patterns for representation of data and metadata are also modelled.
273 -
274 274  There is some similarity between “cube” structures commonly used to process statistical data, and the Data Structure Definition idea in the SDMX Information Model. It is important to note that the data as structured according to the SDMX Information Model is optimized for exchange, potentially with partners who may have no ability to process a “cube” of data coming from complex statistical systems. SDMX time series can be understood as “slices” of the cube. Such a slice is identified by its key. A "series" key consists of the values for all dimensions specified by the key family except time. Thus, it is possible to reconstruct and describe data cubes from SDMX-structured data, and to exchange such databases using the interfaces and formats provided for that purpose in the standard. Additional objects such as hierarchical code lists, constraints and structure maps make it possible to more fully model the structure of cubes.
275 275  
276 276  The information model also provides a view of reference metadata: a mechanism for referencing the meaningful “objects” within the SDMX view of statistical exchange processes (data providers, structures, provisioning agreements, dataflows, metadata flows, etc.) to which metadata is attached; a mechanism for describing a set of meaningful concepts, of organizing them into a presentational structure, and of indicating how their values are represented. This is based on a simple, hierarchical view of reference metadata which is common to many metadata systems and classification/categorization schemes. SDMX provides a model (and XML and JSON formats) for both describing reference metadata structures, and of reporting reference metadata according to those structures.
SUZ.Methodology.Code.MethodologyClass[0]