Changes for page 12 Validation and Transformation Language (VTL)

Last modified by Artur K. on 2026/05/29 14:29

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edited by Helena K.
on 2025/09/10 11:19

Change comment: Migrated property [LightLLMprompt] from class [SKMS.Methodology.Code.MethodologyClass]

To version 21.1

edited by Artur K.
on 2026/05/29 14:29

Change comment: Copied from sdmxsrlocalization:Methodology.SDMX 3\.0 Standards\. Section 6\. Technical Notes.12 Validation and Transformation Language (VTL).WebHome

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--xwiki:XWiki.helena
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@@ -55,7 +55,7 @@
  The [[SDMX-IM>>doc:Glossary.SDMX Information Model.WebHome]]-package-name** **is the concatenation of the string** **[[sdmx>>doc:Glossary.Statistical data and metadata exchange.WebHome]].infomodel." with the package-name, which the [[artefact>>doc:Glossary.Artefact.WebHome]] belongs to. For example, for referencing a [[Dataflow>>doc:Glossary.Dataflow.WebHome]] the [[SDMX-IM>>doc:Glossary.SDMX Information Model.WebHome]]-package-name is [[sdmx>>doc:Glossary.Statistical data and metadata exchange.WebHome]].infomodel.datastructure", because the class [[Dataflow>>doc:Glossary.Dataflow.WebHome]] belongs to the package "datastructure".
--The class-name is the name of the [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] object class, which the [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] object belongs to (e.g., for referencing a [[Dataflow>>doc:Glossary.Dataflow.WebHome]] the class-name is [[Dataflow>>doc:Glossary.Dataflow.WebHome]]"). The [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] can reference [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] [[artefacts>>doc:Glossary.Artefact.WebHome]] that belong to the classes [[Dataflow>>doc:Glossary.Dataflow.WebHome]], [[Dimension>>doc:Glossary.Dimension.WebHome]], TimeDimension, [[Measure>>doc:Glossary.Measure.WebHome]], DataAttribute, (% style="color:#e74c3c" %)[[Concept>>doc:sdmx:Glossary.Concept.WebHome]](%%), [[Codelist>>doc:sdmx:Glossary.Code list.WebHome]].
++The class-name is the name of the [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] object class, which the [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] object belongs to (e.g., for referencing a [[Dataflow>>doc:Glossary.Dataflow.WebHome]] the class-name is [[Dataflow>>doc:Glossary.Dataflow.WebHome]]"). The [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] can reference [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] [[artefacts>>doc:Glossary.Artefact.WebHome]] that belong to the classes [[Dataflow>>doc:Glossary.Dataflow.WebHome]], [[Dimension>>doc:Glossary.Dimension.WebHome]], TimeDimension, [[Measure>>doc:Glossary.Measure.WebHome]], DataAttribute, (% style="color:#e74c3c" %)[[Concept>>doc:Glossary.Concept.WebHome]](%%), [[Codelist>>doc:Glossary.Code list.WebHome]].
  The agency-id is the acronym of the agency that owns the definition of the [[artefact>>doc:Glossary.Artefact.WebHome]], for example for the Eurostat [[artefacts>>doc:Glossary.Artefact.WebHome]] the agency-id is "ESTAT"). The agency-id can be composite (for example AgencyA.Dept1.Unit2).
@@ -63,7 +63,7 @@
  * if the [[artefact>>doc:Glossary.Artefact.WebHome]] is a [[Dataflow>>doc:Glossary.Dataflow.WebHome]], which is a maintainable class, the maintainedobject-id is the [[Dataflow>>doc:Glossary.Dataflow.WebHome]] name ([[dataflow>>doc:Glossary.Dataflow.WebHome]]-id);
  * if the [[artefact>>doc:Glossary.Artefact.WebHome]] is a [[Dimension>>doc:Glossary.Dimension.WebHome]], [[Measure>>doc:Glossary.Measure.WebHome]], TimeDimension 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:Glossary.Artefact.WebHome]] belongs to;
--* if the [[artefact>>doc:Glossary.Artefact.WebHome]] is a (% style="color:#e74c3c" %)[[Concept>>doc:sdmx:Glossary.Concept.WebHome]](%%), 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:Glossary.Artefact.WebHome]] belongs to;
++* if the [[artefact>>doc:Glossary.Artefact.WebHome]] is a (% style="color:#e74c3c" %)[[Concept>>doc:Glossary.Concept.WebHome]](%%), 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:Glossary.Artefact.WebHome]] belongs to;
  * if the [[artefact>>doc:Glossary.Artefact.WebHome]] is a Codelist, which is a maintainable class, the maintainedobject-id is the Codelist name (codelist-id).
  The maintainedobject-version is the version, according to the [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] versioning rules, of the maintained object which the [[artefact>>doc:Glossary.Artefact.WebHome]] belongs to (for example, possible versions might be 1.0, 2.3, 1.0.0, 2.1.0 or 3.1.2).
@@ -73,7 +73,7 @@
  The object-id is the name of the non-[[maintainable artefact>>doc:Glossary.Maintainable artefact.WebHome]] (when the [[artefact>>doc:Glossary.Artefact.WebHome]] is maintainable its name is already specified as the maintainedobject-id, see above), in particular it has to be specified:
  * if the [[artefact>>doc:Glossary.Artefact.WebHome]] is a [[Dimension>>doc:Glossary.Dimension.WebHome]], TimeDimension, [[Measure>>doc:Glossary.Measure.WebHome]] or DataAttribute (the object-id is the name of one of the [[artefacts>>doc:Glossary.Artefact.WebHome]] above, which are data structure [[components>>doc:Glossary.Component.WebHome]])
--* if the [[artefact>>doc:Glossary.Artefact.WebHome]] is a (% style="color:#e74c3c" %)[[Concept>>doc:sdmx:Glossary.Concept.WebHome]](%%) (the object-id is the name of the (% style="color:#e74c3c" %)[[Concept>>doc:sdmx:Glossary.Concept.WebHome]](%%))
++* if the [[artefact>>doc:Glossary.Artefact.WebHome]] is a (% style="color:#e74c3c" %)[[Concept>>doc:Glossary.Concept.WebHome]](%%) (the object-id is the name of the (% style="color:#e74c3c" %)[[Concept>>doc:Glossary.Concept.WebHome]](%%))
  For example, by using the URN, the [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] Transformation that sums two [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] [[Dataflows>>doc:Glossary.Dataflow.WebHome]] DF1 and DF2 and assigns the result to a third persistent [[Dataflow>>doc:Glossary.Dataflow.WebHome]] DFR, assuming that DF1, DF2 and DFR are the maintainedobject-id of the three [[Dataflows>>doc:Glossary.Dataflow.WebHome]], that their version is 1.0.0 and their Agency is AG, would be written as{{footnote}}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.{{/footnote}}:
@@ -88,16 +88,16 @@
  The URN can be abbreviated by omitting the parts that are not essential for the identification of the [[artefact>>doc: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.
  * The SDMXprefix can be omitted for all the [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] objects, because it is a prefixed string (urn:[[sdmx>>doc:Glossary.Statistical data and metadata exchange.WebHome]]:org), always the same for [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] objects. • The [[SDMX-IM>>doc: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:Glossary.SDMX Information Model.WebHome]] packages and classes that allows this deduction is in the [[SDMX>>doc: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:Glossary.Artefact.WebHome]] that [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] can reference, the package is:
--** "datastructure" for the classes [[Dataflow>>doc:Glossary.Dataflow.WebHome]], [[Dimension>>doc:Glossary.Dimension.WebHome]], TimeDimension, [[Measure>>doc:Glossary.Measure.WebHome]], DataAttribute, o "conceptscheme" for the class (% style="color:#e74c3c" %)[[Concept>>doc:sdmx:Glossary.Concept.WebHome]](%%), or "[[codelist>>doc:sdmx:Glossary.Code list.WebHome]]" for the class [[Codelist>>doc:sdmx:Glossary.Code list.WebHome]].
++** "datastructure" for the classes [[Dataflow>>doc:Glossary.Dataflow.WebHome]], [[Dimension>>doc:Glossary.Dimension.WebHome]], TimeDimension, [[Measure>>doc:Glossary.Measure.WebHome]], DataAttribute, o "conceptscheme" for the class (% style="color:#e74c3c" %)[[Concept>>doc:Glossary.Concept.WebHome]](%%), or "[[codelist>>doc:Glossary.Code list.WebHome]]" for the class [[Codelist>>doc:Glossary.Code list.WebHome]].
  * The class-name can be omitted as it can be deduced from the [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] invocation. In particular, starting from the [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] class of the invoked [[artefact>>doc:Glossary.Artefact.WebHome]] (e.g. [[dataset>>doc:Glossary.Data set.WebHome]], [[component>>doc:Glossary.Component.WebHome]], identifier, [[measure>>doc:Glossary.Measure.WebHome]], [[attribute>>doc:Glossary.Attribute.WebHome]], variable, valuedomain), which is known given the syntax of the invoking [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] operator{{footnote}}For the syntax of the VTL operators see the VTL Reference Manual{{/footnote}}, the [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] class can be deduced from the mapping rules between [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] and [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] (see the section Mapping between [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] and [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] hereinafter){{footnote}}In case the invoked artefact is a VTL component, which can be invoked only within the invocation of a VTL data set (SDMX Dataflow), the specific SDMX class-name (e.g. Dimension, TimeDimension, Measure or DataAttribute) can be deduced from the data structure of the SDMX Dataflow, which the component belongs to.{{/footnote}}.
  * 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:Glossary.Artefact.WebHome]] is invoked. For example, the agencyid can be omitted if it is the same as the invoking TransformationScheme and cannot be omitted if the [[artefact>>doc:Glossary.Artefact.WebHome]] comes from another agency{{footnote}}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){{/footnote}}. Take also into account that, according to the [[VTL>>doc: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).
  * 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:Glossary.Artefact.WebHome]] is a [[Dataflow>>doc:Glossary.Dataflow.WebHome]], which is a maintainable class, the maintainedobject-id is the [[dataflow>>doc:Glossary.Dataflow.WebHome]]-id and obviously cannot be omitted;
  ** if the referenced [[artefact>>doc:Glossary.Artefact.WebHome]] is a [[Dimension>>doc:Glossary.Dimension.WebHome]], TimeDimension, [[Measure>>doc:Glossary.Measure.WebHome]], 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:Glossary.Component.WebHome]] are always invoked within the invocation of a [[Dataflow>>doc:Glossary.Dataflow.WebHome]], whose dataStructure-id can be deduced from the [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] structural definitions;
  **
--*** if the referenced [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] is a (% style="color:#e74c3c" %)[[Concept>>doc:sdmx:Glossary.Concept.WebHome]](%%), which is not maintainable and belong to the ConceptScheme maintainable class, the maintained object is the conceptScheme-id and cannot be omitted;
--*** if the referenced [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]] is a [[Codelist>>doc:sdmx:Glossary.Code list.WebHome]], which is a maintainable class, the maintainedobject-id is the [[codelist>>doc:sdmx:Glossary.Code list.WebHome]]-id and obviously cannot be omitted.
--** When the maintainedobject-id is omitted, the maintainedobject-(% style="color: rgb(231, 76, 60); color: rgb(231, 76, 60)" %)version(%%) is omitted too. When the maintainedobject-id is not omitted and the maintainedobject-(% style="color:#e74c3c" %)version(%%) is omitted, the (% style="color: rgb(231, 76, 60); color: rgb(231, 76, 60)" %)version(%%) 1.0 is assumed by default. • 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
--** The object-id does not exist for the [[artefacts>>doc:sdmx:Glossary.Artefact.WebHome]] belonging to the [[Dataflow>>doc:sdmx:Glossary.Dataflow.WebHome]], and [[Codelist>>doc:sdmx:Glossary.Code list.WebHome]] 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]], TimeDimension, [[Measure>>doc:sdmx:Glossary.Measure.WebHome]], DataAttribute and (% style="color:#e74c3c" %)[[Concept>>doc:sdmx:Glossary.Concept.WebHome]](%%), as for them the object-id is the main identifier of the [[artefact>>doc:sdmx:Glossary.Artefact.WebHome]].
++*** if the referenced [[artefact>>doc:Glossary.Artefact.WebHome]] is a (% style="color:#e74c3c" %)[[Concept>>doc:Glossary.Concept.WebHome]](%%), which is not maintainable and belong to the ConceptScheme maintainable class, the maintained object is the conceptScheme-id and cannot be omitted;
++*** if the referenced [[artefact>>doc:Glossary.Artefact.WebHome]] is a [[Codelist>>doc:Glossary.Code list.WebHome]], which is a maintainable class, the maintainedobject-id is the [[codelist>>doc:Glossary.Code list.WebHome]]-id and obviously cannot be omitted.
++** When the maintainedobject-id is omitted, the maintainedobject-(% style="color: rgb(231, 76, 60); color: rgb(231, 76, 60)" %)version(%%) is omitted too. When the maintainedobject-id is not omitted and the maintainedobject-(% style="color:#e74c3c" %)version(%%) is omitted, the (% style="color: rgb(231, 76, 60); color: rgb(231, 76, 60)" %)version(%%) 1.0 is assumed by default. • As said, the container-object-id does not apply to the classes that can be referenced in [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] Transformations, therefore is not present in their URN
++** The object-id does not exist for the [[artefacts>>doc:Glossary.Artefact.WebHome]] belonging to the [[Dataflow>>doc:Glossary.Dataflow.WebHome]], and [[Codelist>>doc:Glossary.Code list.WebHome]] classes, while it exists and cannot be omitted for the [[artefacts>>doc:Glossary.Artefact.WebHome]] belonging to the classes [[Dimension>>doc:Glossary.Dimension.WebHome]], TimeDimension, [[Measure>>doc:Glossary.Measure.WebHome]], DataAttribute and (% style="color:#e74c3c" %)[[Concept>>doc:Glossary.Concept.WebHome]](%%), as for them the object-id is the main identifier of the [[artefact>>doc:Glossary.Artefact.WebHome]].
  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.
@@ -133,9 +133,9 @@
  'DFR(1.0.0)' := 'DF1(1.0.0)' [rename SECTOR to SEC]
--In the references to the (% style="color:#e74c3c" %)[[Concepts>>doc:sdmx:Glossary.Concept.WebHome]](%%), 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>>doc:sdmx:Glossary.Concept.WebHome]](%%)-id must be specified.
++In the references to the (% style="color:#e74c3c" %)[[Concepts>>doc:Glossary.Concept.WebHome]](%%), which can exist for example in the definition of the [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] Rulesets, at least the conceptScheme-id and the (% style="color:#e74c3c" %)[[concept>>doc:Glossary.Concept.WebHome]](%%)-id must be specified.
--An example of non-abbreviated reference, if the conceptScheme-id is CS1 and the (% style="color:#e74c3c" %)[[concept>>doc:sdmx:Glossary.Concept.WebHome]](%%)-id is SECTOR, is the following:
++An example of non-abbreviated reference, if the conceptScheme-id is CS1 and the (% style="color:#e74c3c" %)[[concept>>doc:Glossary.Concept.WebHome]](%%)-id is SECTOR, is the following:
  'urn:sdmx:org.sdmx.infomodel.conceptscheme.Concept=AG:CS1(1.0.0).SECTOR'
@@ -147,7 +147,7 @@
  'DFR(1.0.0)' := between ( 'DF1(1.0.0)', 0, 25000 )
--The [[artefact>>doc:Glossary.Artefact.WebHome]] ([[Component>>doc:Glossary.Component.WebHome]], (% style="color:#e74c3c" %)[[Concept>>doc:sdmx:Glossary.Concept.WebHome]](%%), [[Codelist>>doc:sdmx:Glossary.Code list.WebHome]] …) 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: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:Glossary.Measure.WebHome]] of DF1(1.0.0).
++The [[artefact>>doc:Glossary.Artefact.WebHome]] ([[Component>>doc:Glossary.Component.WebHome]], (% style="color:#e74c3c" %)[[Concept>>doc:Glossary.Concept.WebHome]](%%), [[Codelist>>doc:Glossary.Code list.WebHome]] …) 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: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:Glossary.Measure.WebHome]] of DF1(1.0.0).
  === 12.2.4 User-defined alias ===
@@ -161,11 +161,11 @@
  The [[VTL>>doc: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.
--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>>doc:sdmx:Glossary.Code list.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>>doc:sdmx:Glossary.Concept.WebHome]](%%), assuming for it a definite representation{{footnote}}Rulesets of this kind cannot be reused when the referenced Concept has a different representation.{{/footnote}}.
++In the signature, given the mapping between [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] and [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] better described in the following paragraphs, a reference to a [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] Value Domain becomes a reference to a [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] [[Codelist>>doc:Glossary.Code list.WebHome]], while a reference to a [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] Represented Variable becomes a reference to a [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] (% style="color:#e74c3c" %)[[Concept>>doc:Glossary.Concept.WebHome]](%%), assuming for it a definite representation{{footnote}}Rulesets of this kind cannot be reused when the referenced Concept has a different representation.{{/footnote}}.
--In general, for referencing [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Codelists>>doc:sdmx:Glossary.Code list.WebHome]] and (% style="color:#e74c3c" %)[[Concepts>>doc:sdmx:Glossary.Concept.WebHome]](%%), 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 mapped to [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]].{{footnote}}See also the section "VTL-DL Rulesets" in the VTL Reference Manual.{{/footnote}}
++In general, for referencing [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] [[Codelists>>doc:Glossary.Code list.WebHome]] and (% style="color:#e74c3c" %)[[Concepts>>doc:Glossary.Concept.WebHome]](%%), the conventions described in the previous paragraphs apply. In the Ruleset syntax, the elements that reference [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] [[artefacts>>doc: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 mapped to [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]].{{footnote}}See also the section "VTL-DL Rulesets" in the VTL Reference Manual.{{/footnote}}
--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>>doc:sdmx:Glossary.Code list.WebHome]], (% style="color:#e74c3c" %)[[Concept>>doc:sdmx:Glossary.Concept.WebHome]](%%)) to can be deduced from the Ruleset signature.
++In the body of the Rulesets, the [[Codes>>doc:Glossary.Code.WebHome]] and in general all the Values can be written without any other specification, because the [[artefact>>doc:Glossary.Artefact.WebHome]], which the Values are referred ([[Codelist>>doc:Glossary.Code list.WebHome]], (% style="color:#e74c3c" %)[[Concept>>doc:Glossary.Concept.WebHome]](%%)) to can be deduced from the Ruleset signature.
  == 12.3 Mapping between SDMX and VTL artefacts ==
@@ -336,7 +336,7 @@
  If desired, this method can be applied also to mono-[[measure>>doc:Glossary.Measure.WebHome]] [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] structures, provided that none of the [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] [[Components>>doc:Glossary.Component.WebHome]] has already the role of [[Measure>>doc:Glossary.Measure.WebHome]] Identifier. Like in the general case, a MeasureDimension [[component>>doc:Glossary.Component.WebHome]] called “measure_name” is added to the [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] DataStructure, in this case it has just one possible [[Code>>doc:Glossary.Code.WebHome]], corresponding to the name of the unique [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] [[Measure>>doc:Glossary.Measure.WebHome]]. The original [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] [[Measure>>doc:Glossary.Measure.WebHome]] would not become a [[Component>>doc:Glossary.Component.WebHome]] in the [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] data structure. The value of the [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] [[Measure>>doc:Glossary.Measure.WebHome]] would be assigned to the unique [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] [[Measure>>doc:Glossary.Measure.WebHome]] called “obs_value”.
--In any case, the resulting [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] definitions must be compliant with the [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] consistency rules. For example, the possible [[Codes>>doc:Glossary.Code.WebHome]] of the [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] MeasureDimension need to be listed in a [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Codelist>>doc:sdmx:Glossary.Code list.WebHome]], with proper id, agency and [[version>>doc:Glossary.Version.WebHome]]; moreover, the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[DSD>>doc:sdmx:Glossary.Data structure definition.WebHome]] must have the AttributeRelationship for the DataAttributes, which does not exist in [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]].
++In any case, the resulting [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] definitions must be compliant with the [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] consistency rules. For example, the possible [[Codes>>doc:Glossary.Code.WebHome]] of the [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] MeasureDimension need to be listed in a [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] [[Codelist>>doc:Glossary.Code list.WebHome]], with proper id, agency and [[version>>doc:Glossary.Version.WebHome]]; moreover, the [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] [[DSD>>doc:Glossary.Data structure definition.WebHome]] must have the AttributeRelationship for the DataAttributes, which does not exist in [[VTL>>doc:Glossary.Validation and transformation language.WebHome]].
  ==== 12.3.4.3 From VTL Measures to SDMX Data Attributes ====
@@ -474,7 +474,7 @@
  |(% style="width:278px" %)**VTL**|(% style="width:613px" %)**SDMX**
  |(% style="width:278px" %)**[[Data Set>>doc:Glossary.Data set.WebHome]] [[Component>>doc:Glossary.Component.WebHome]]**|(% style="width:613px" %)Although this abstraction exists in [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]], it does not have an explicit definition and correspond to a [[Component>>doc:Glossary.Component.WebHome]] (either a DimensionComponent or a [[Measure>>doc:Glossary.Measure.WebHome]] or a DataAttribute) belonging to one specific [[Dataflow>>doc:Glossary.Dataflow.WebHome]]{{footnote}}Through SDMX Constraints, it is possible to specify the values that a Component of a Dataflow can assume.{{/footnote}}
  |(% style="width:278px" %)**Represented Variable**|(% style="width:613px" %)(((
--(% style="color:#e74c3c" %)**[[Concept>>doc:sdmx:Glossary.Concept.WebHome]]**(%%) with a definite
++(% style="color:#e74c3c" %)**[[Concept>>doc:Glossary.Concept.WebHome]]**(%%) with a definite
  [[Representation>>doc:Glossary.Representation.WebHome]]
  )))
@@ -482,7 +482,7 @@
  **[[Representation>>doc:Glossary.Representation.WebHome]]** (see the Structure Pattern in the Base Package)
  )))
  |(% style="width:278px" %)**Enumerated Value Domain /
--[[Code>>doc:Glossary.Code.WebHome]] List**|(% style="width:613px" %)**[[Codelist>>doc:sdmx:Glossary.Code list.WebHome]]**
++[[Code>>doc:Glossary.Code.WebHome]] List**|(% style="width:613px" %)**[[Codelist>>doc:Glossary.Code list.WebHome]]**
  |(% style="width:278px" %)**[[Code>>doc:Glossary.Code.WebHome]]**|(% style="width:613px" %)(((
  **[[Code>>doc:Glossary.Code.WebHome]]** (for enumerated DimensionComponent, [[Measure>>doc:Glossary.Measure.WebHome]], DataAttribute)
  )))
@@ -489,7 +489,7 @@
  |(% style="width:278px" %)**Described Value Domain**|(% style="width:613px" %)(((
  non-enumerated** [[Representation>>doc:Glossary.Representation.WebHome]] **(having [[Facets>>doc:Glossary.Facet.WebHome]] / ExtendedFacets, see the Structure Pattern in the Base Package)
  )))
--|(% style="width:278px" %)**Value**|(% style="width:613px" %)Although this abstraction exists in [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]], it does not have an explicit definition and correspond to a **[[Code>>doc:Glossary.Code.WebHome]]** of a [[Codelist>>doc:sdmx:Glossary.Code list.WebHome]] (for enumerated [[Representations>>doc:Glossary.Representation.WebHome]]) or to a valid **value **(for non-enumerated** **[[Representations>>doc:Glossary.Representation.WebHome]])
++|(% style="width:278px" %)**Value**|(% style="width:613px" %)Although this abstraction exists in [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]], it does not have an explicit definition and correspond to a **[[Code>>doc:Glossary.Code.WebHome]]** of a [[Codelist>>doc:Glossary.Code list.WebHome]] (for enumerated [[Representations>>doc:Glossary.Representation.WebHome]]) or to a valid **value **(for non-enumerated** **[[Representations>>doc:Glossary.Representation.WebHome]])
  |(% style="width:278px" %)**Value Domain Subset / Set**|(% style="width:613px" %)This abstraction does not exist in [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]]
  |(% style="width:278px" %)**Enumerated Value Domain Subset / Enumerated Set**|(% style="width:613px" %)This abstraction does not exist in [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]]
  |(% style="width:278px" %)**Described Value Domain Subset / Described Set**|(% style="width:613px" %)This abstraction does not exist in [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]]
@@ -497,19 +497,19 @@
  The main difference between [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] and [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] relies on the fact that the [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] [[artefacts>>doc:Glossary.Artefact.WebHome]] for defining subsets of Value Domains do not exist in [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]], therefore the [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] features for referring to predefined subsets are not available in [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]]. These [[artefacts>>doc: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:Glossary.Data set.WebHome]] [[Component>>doc:Glossary.Component.WebHome]] (aimed at defining the set of values that the [[Component>>doc:Glossary.Component.WebHome]] of a [[Data Set>>doc:Glossary.Data set.WebHome]] can take, possibly a subset of the [[codes>>doc:Glossary.Code.WebHome]] of Value Domain).
--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>>doc:sdmx:Glossary.Code list.WebHome]] (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>>doc:sdmx:Glossary.Code list.WebHome]]). As for the mapping between [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] variables and [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Concepts>>doc:sdmx:Glossary.Concept.WebHome]], 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{{footnote}}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.{{/footnote}}, while the [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Concepts>>doc:sdmx:Glossary.Concept.WebHome]] can have different [[Representations>>doc:sdmx:Glossary.Representation.WebHome]] in different DataStructures.{{footnote}}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.{{/footnote}} This means that one [[SDMX>>doc:sdmx:Glossary.Statistical data and metadata exchange.WebHome]] [[Concept>>doc:sdmx:Glossary.Concept.WebHome]] can correspond to many [[VTL>>doc:sdmx:Glossary.Validation and transformation language.WebHome]] Variables, one for each [[representation>>doc:sdmx:Glossary.Representation.WebHome]] the [[Concept>>doc:sdmx:Glossary.Concept.WebHome]] has.
++Another difference consists in the fact that all Value Domains are considered as identifiable objects in [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] either if enumerated or not, while in [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] the [[Codelist>>doc:Glossary.Code list.WebHome]] (corresponding to a [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] enumerated Value Domain) is identifiable, while the [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] non-enumerated [[Representation>>doc:Glossary.Representation.WebHome]] (corresponding to a [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] non-enumerated Value Domain) is not identifiable. As a consequence, the definition of the [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] Rulesets, which in [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] can refer either to enumerated or non-enumerated value domains, in [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] can refer only to enumerated Value Domains (i.e. to [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] [[Codelists>>doc:Glossary.Code list.WebHome]]). As for the mapping between [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] variables and [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] [[Concepts>>doc:Glossary.Concept.WebHome]], it should be noted that these [[artefacts>>doc:Glossary.Artefact.WebHome]] do not coincide perfectly. In fact, the [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] variables are represented variables, defined always on the same Value Domain (“[[Representation>>doc:Glossary.Representation.WebHome]]” in [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]]) independently of the [[data set>>doc:Glossary.Data set.WebHome]] / data structure in which they appear{{footnote}}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.{{/footnote}}, while the [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] [[Concepts>>doc:Glossary.Concept.WebHome]] can have different [[Representations>>doc:Glossary.Representation.WebHome]] in different DataStructures.{{footnote}}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.{{/footnote}} This means that one [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] [[Concept>>doc:Glossary.Concept.WebHome]] can correspond to many [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] Variables, one for each [[representation>>doc:Glossary.Representation.WebHome]] the [[Concept>>doc:Glossary.Concept.WebHome]] has.
--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]] 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
++Therefore, it is important to be aware that some [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] operations (for example the binary operations at [[data set>>doc:Glossary.Data set.WebHome]] level) are consistent only if the [[components>>doc:Glossary.Component.WebHome]] having the same names in the operated [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] [[Data Sets>>doc:Glossary.Data set.WebHome]] have also the same [[representation>>doc:Glossary.Representation.WebHome]] (i.e. the same Value Domain as for [[VTL>>doc:Glossary.Validation and transformation language.WebHome]]). For example, it is possible to obtain correct results from the [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] expression
  DS_c := DS_a + DS_b (where DS_a, DS_b, DS_c are [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] [[Data Sets>>doc:Glossary.Data set.WebHome]])
  if the matching [[components>>doc:Glossary.Component.WebHome]] in DS_a and DS_b (e.g. ref_date, geo_area, sector …) refer to the same general [[representation>>doc:Glossary.Representation.WebHome]]. In simpler words, DS_a and DS_b must use the same values/[[codes>>doc: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.
--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>>doc:sdmx:Glossary.Concept.WebHome]](%%) 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]]
++As mentioned, the property above is not enforced by construction in [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]], and different [[representations>>doc:Glossary.Representation.WebHome]] of the same (% style="color:#e74c3c" %)[[Concept>>doc:Glossary.Concept.WebHome]](%%) can be not compatible one another (for example, it may happen that geo_area is represented by ISO-alpha-3 [[codes>>doc:Glossary.Code.WebHome]] in DS_a and by ISO alpha-2 [[codes>>doc:Glossary.Code.WebHome]] in DS_b). Therefore, it will be up to the definer of [[VTL>>doc: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>>doc:sdmx:Glossary.Concept.WebHome]](%%).
++Transformations to ensure that the [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] expressions are consistent with the actual [[representations>>doc:Glossary.Representation.WebHome]] of the correspondent [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] (% style="color:#e74c3c" %)[[Concepts>>doc:Glossary.Concept.WebHome]](%%).
--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>>doc:sdmx:Glossary.Concept.WebHome]](%%)), i.e. assuming definite [[representations>>doc:sdmx:Glossary.Representation.WebHome]] for them (e.g. ISOalpha-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>>doc:sdmx:Glossary.Concept.WebHome]](%%) they refer to but different [[representations>>doc:sdmx:Glossary.Representation.WebHome]] (e.g. ISO-alpha-2 for country), the Ruleset cannot work properly.
++It remains up to the [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]]-[[VTL>>doc:Glossary.Validation and transformation language.WebHome]] definer also the assurance of the consistency between a [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] Ruleset defined on Variables and the [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] [[Components>>doc:Glossary.Component.WebHome]] on which the Ruleset is applied. In fact, a [[VTL>>doc:Glossary.Validation and transformation language.WebHome]] Ruleset is expressed by means of the values of the Variables (i.e. [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] (% style="color:#e74c3c" %)[[Concepts>>doc:Glossary.Concept.WebHome]](%%)), i.e. assuming definite [[representations>>doc:Glossary.Representation.WebHome]] for them (e.g. ISOalpha-3 for country). If the Ruleset is applied to [[SDMX>>doc:Glossary.Statistical data and metadata exchange.WebHome]] [[Components>>doc:Glossary.Component.WebHome]] that have the same name of the (% style="color:#e74c3c" %)[[Concept>>doc:Glossary.Concept.WebHome]](%%) they refer to but different [[representations>>doc:Glossary.Representation.WebHome]] (e.g. ISO-alpha-2 for country), the Ruleset cannot work properly.
  == 12.4 Mapping between SDMX and VTL Data Types ==