Changes for page 12 Validation and Transformation Language (VTL)

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  === 12.3.1. When the mapping occurs ===
--The (% style="color:#e74c3c" %)mapping(%%) methods between the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] and [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] object classes allow transforming a [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] definition in a [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] one and vice-versa for the [[artefacts>>doc:sdmx:Glossary 2\.1.Artefact.WebHome]] to be manipulated. It should be remembered that [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] programs (i.e. Transformation Schemes) are represented in [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] through the TransformationScheme maintainable class which is composed of Transformations ([[nameable artefacts>>doc:sdmx:Glossary 2\.1.Nameable artefact.WebHome]]). Each Transformation assigns the outcome of the evaluation of a [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] expression to a result: the input operands of the expression and the result can be [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] [[artefacts>>doc:sdmx:Glossary 2\.1.Artefact.WebHome]]. Every time a [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] object is referenced in a [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] Transformation as an input operand, there is the need to generate a [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] definition of the object, so that the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] operations can take place. This can be made starting from the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] definition and applying a [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]]-[[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] (% style="color:#e74c3c" %)mapping(%%) method in the direction from [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]]. The possible (% style="color:#e74c3c" %)mapping(%%) methods from [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary 2\.1.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 2\.1.Validation and transformation language.WebHome]] definition of the object from the knowledge of the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] definition.
++The mapping methods between the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] and [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] object classes allow transforming a [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] definition in a [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] one and vice-versa for the [[artefacts>>doc:sdmx:Glossary 2\.1.Artefact.WebHome]] to be manipulated. It should be remembered that [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] programs (i.e. Transformation Schemes) are represented in [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] through the TransformationScheme maintainable class which is composed of Transformations ([[nameable artefacts>>doc:sdmx:Glossary 2\.1.Nameable artefact.WebHome]]). Each Transformation assigns the outcome of the evaluation of a [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] expression to a result: the input operands of the expression and the result can be [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] [[artefacts>>doc:sdmx:Glossary 2\.1.Artefact.WebHome]]. Every time a [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] object is referenced in a [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] Transformation as an input operand, there is the need to generate a [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] definition of the object, so that the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] operations can take place. This can be made starting from the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] definition and applying a [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]]-[[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] mapping method in the direction from [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]]. The possible mapping methods from [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary 2\.1.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 2\.1.Validation and transformation language.WebHome]] definition of the object from the knowledge of the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] definition.
  In the opposite direction, every time an object calculated by means of [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] must be treated as a [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] object (for example for exchanging it through [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]]), there is the need of a [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] definition of the object, so that the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] operations can take place. The [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] definition is needed for the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] objects for which a [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] use is envisaged{{footnote}}If a calculated artefact is persistent, it needs a persistent definition, i.e. a SDMX definition in a SDMX environment. In addition, possible calculated artefact that are not persistent may require a SDMX definition, for example when the result of a nonpersistent calculation is disseminated through SDMX tools (like an inquiry tool).{{/footnote}}.
--The (% style="color:#e74c3c" %)mapping(%%) methods from [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] to [[SDMX>>doc:sdmx:Glossary 2\.1.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 2\.1.Statistical data and metadata exchange.WebHome]] definition to be automatically deduced from the [[VTL>>doc:sdmx:Glossary 2\.1.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 2\.1.Statistical data and metadata exchange.WebHome]] [[DSD>>doc:sdmx:Glossary 2\.1.Data structure definition.WebHome]] includes also some mandatory information not available in [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] (like the [[concept scheme>>doc:sdmx:Glossary 2\.1.Concept scheme.WebHome]] to which the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] [[components>>doc:sdmx:Glossary 2\.1.Component.WebHome]] refer, the ‘usage’ and ‘attributeRelationship’ for the DataAttributes and so on). Therefore the (% style="color:#e74c3c" %)mapping(%%) methods from [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] to [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] provide only a general guidance for generating [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] definitions properly starting from the information available in [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]], independently of how the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] definition it is actually generated (manually, automatically or part and part).
++The mapping methods from [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] to [[SDMX>>doc:sdmx:Glossary 2\.1.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 2\.1.Statistical data and metadata exchange.WebHome]] definition to be automatically deduced from the [[VTL>>doc:sdmx:Glossary 2\.1.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 2\.1.Statistical data and metadata exchange.WebHome]] [[DSD>>doc:sdmx:Glossary 2\.1.Data structure definition.WebHome]] includes also some mandatory information not available in [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] (like the [[concept scheme>>doc:sdmx:Glossary 2\.1.Concept scheme.WebHome]] to which the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] [[components>>doc:sdmx:Glossary 2\.1.Component.WebHome]] refer, the ‘usage’ and ‘attributeRelationship’ for the DataAttributes and so on). Therefore the mapping methods from [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] to [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] provide only a general guidance for generating [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] definitions properly starting from the information available in [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]], independently of how the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] definition it is actually generated (manually, automatically or part and part).
  === 12.3.2 General mapping of VTL and SDMX data structures ===
  This section makes reference to the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] "Model for data and their structure"{{footnote}}See the VTL 2.0 User Manual{{/footnote}} and the correspondent [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] "[[Data Structure Definition>>doc:sdmx:Glossary 2\.1.Data structure definition.WebHome]]"{{footnote}}See the SDMX Standards Section 2 – Information Model{{/footnote}}.
--The main type of [[artefact>>doc:sdmx:Glossary 2\.1.Artefact.WebHome]] that the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] can manipulate is the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] [[Data Set>>doc:sdmx:Glossary 2\.1.Data set.WebHome]], which in general is (% style="color:#e74c3c" %)mapped(%%) to the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] [[Dataflow>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]]. This means that a [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] Transformation, in the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] context, expresses the algorithm for calculating a derived [[Dataflow>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]] starting from some already existing [[Dataflows>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]] (either collected or derived).{{footnote}}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.{{/footnote}}
++The main type of [[artefact>>doc:sdmx:Glossary 2\.1.Artefact.WebHome]] that the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] can manipulate is the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] [[Data Set>>doc:sdmx:Glossary 2\.1.Data set.WebHome]], which in general is mapped to the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] [[Dataflow>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]]. This means that a [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] Transformation, in the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] context, expresses the algorithm for calculating a derived [[Dataflow>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]] starting from some already existing [[Dataflows>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]] (either collected or derived).{{footnote}}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.{{/footnote}}
  While the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] Transformations are defined in term of [[Dataflow>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]] definitions, they are assumed to be executed on instances of such [[Dataflows>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]], provided at runtime to the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] engine (the mechanism for identifying the instances to be processed are not part of the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] specifications and depend on the implementation of the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]]-based systems). As already said, the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] [[Datasets>>doc:sdmx:Glossary 2\.1.Data set.WebHome]] are instances of [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] [[Dataflows>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]], therefore a [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] Transformation defined on some [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] [[Dataflows>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]] can be applied on some corresponding [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] [[Datasets>>doc:sdmx:Glossary 2\.1.Data set.WebHome]].
@@ -202,18 +202,18 @@
  Correspondingly, in the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] implementation of the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]], the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] Identifiers can be (optionally) distinguished in similar sub-classes (Simple Identifier, Time Identifier) even if such a distinction is not evidenced in the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] IM.
--The possible (% style="color:#e74c3c" %)mapping(%%) options are described in more detail in the following sections.
++The possible mapping options are described in more detail in the following sections.
  === 12.3.3 Mapping from SDMX to VTL data structures ===
  ==== 12.3.3.1 Basic Mapping ====
--The main (% style="color:#e74c3c" %)mapping(%%) method from [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] is called **Basic **(% style="color:#e74c3c" %)mapping(%%). This is considered as the default (% style="color:#e74c3c" %)mapping(%%) method and is applied unless a different method is specified through the VtlMappingScheme and VtlDataflowMapping classes.
++The main mapping method from [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary 2\.1.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.
  When transforming **from [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]]**, this method consists in leaving the [[components>>doc:sdmx:Glossary 2\.1.Component.WebHome]] unchanged and maintaining their names and roles, according to the following table:
  (% style="width:468.294px" %)
--|(% style="width:196px" %)**[[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]]**|(% style="width:269px" %)**[[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]]**
++|(% style="width:196px" %)**SDMX**|(% style="width:269px" %)**VTL**
  |(% style="width:196px" %)[[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]]|(% style="width:269px" %)(Simple) Identifier
  |(% style="width:196px" %)TimeDimension|(% style="width:269px" %)(Time) Identifier
  |(% style="width:196px" %)[[Measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]]|(% style="width:269px" %)[[Measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]]
@@ -221,33 +221,33 @@
  The [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] DataAttributes, in [[VTL>>doc:sdmx:Glossary 2\.1.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 2\.1.Validation and transformation language.WebHome]] Identifiers), because [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] does not have the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] AttributeRelationships, which defines the construct to which the DataAttribute is related (e.g. observation, [[dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] or set or group of [[dimensions>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]], whole [[data set>>doc:sdmx:Glossary 2\.1.Data set.WebHome]]).
--With the Basic (% style="color:#e74c3c" %)mapping(%%), one [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] observation^^27^^ generates one [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] data point.
++With the Basic mapping, one [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] observation^^27^^ generates one [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] data point.
  ==== 12.3.3.2 Pivot Mapping ====
--An alternative (% style="color:#e74c3c" %)mapping(%%) method from [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] is the **Pivot **(% style="color:#e74c3c" %)mapping(%%), which makes sense and is different from the Basic method only for the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] data structures that contain a [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] that plays the role of [[measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] [[dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] (like in [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] 2.1) and just one [[Measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]]. Through this method, these structures can be (% style="color:#e74c3c" %)mapped(%%) to multimeasure [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] data structures. Besides that, a user may choose to use any [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] acting as a list of [[Measures>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] (e.g., a [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] with [[indicators>>doc:sdmx:Glossary 2\.1.Statistical indicator.WebHome]]), either by considering the “[[Measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]]” role of a [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]], or at will using any coded [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]]. Of course, in [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] 3.0, this can only work when only one [[Measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] is defined in the [[DSD>>doc:sdmx:Glossary 2\.1.Data structure definition.WebHome]].
++An alternative mapping method from [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] is the **Pivot **mapping, which makes sense and is different from the Basic method only for the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] data structures that contain a [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] that plays the role of [[measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] [[dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] (like in [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] 2.1) and just one [[Measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]]. Through this method, these structures can be mapped to multimeasure [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] data structures. Besides that, a user may choose to use any [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] acting as a list of [[Measures>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] (e.g., a [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] with [[indicators>>doc:sdmx:Glossary 2\.1.Statistical indicator.WebHome]]), either by considering the “[[Measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]]” role of a [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]], or at will using any coded [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]]. Of course, in [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] 3.0, this can only work when only one [[Measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] is defined in the [[DSD>>doc:sdmx:Glossary 2\.1.Data structure definition.WebHome]].
--In [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] 2.1 the MeasureDimension was a subclass of DimensionComponent like [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] and TimeDimension. In the current [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] (% style="color:#e74c3c" %)version(%%), this subclass does not exist anymore, however a [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] can have the role of [[measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] [[dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] (i.e. a [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] that contributes to the identification of the [[measures>>doc:sdmx:Glossary 2\.1.Measure.WebHome]]). In [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] 2.1 a DataStructure could have zero or one MeasureDimensions, in the current (% style="color:#e74c3c" %)version(%%) of the standard, from zero to many [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] may have the role of [[measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] [[dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]]. Hereinafter a [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] that plays the role of [[measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] [[dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] is referenced for simplicity as “MeasureDimension“, i.e. maintaining the capital letters and the courier font even if the MeasureDimension is not anymore a class in the [[SDMX Information Model>>doc:sdmx:Glossary 2\.1.SDMX Information Model.WebHome]] of the current [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] (% style="color:#e74c3c" %)version(%%). For the sake of simplicity, the description below considers just one [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] having the role of MeasureDimension (i.e., the more simple and common case). Nevertheless, it maintains its validity also if in the DataStructure there are more [[dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] with the role of MeasureDimensions: in this case what is said about the MeasureDimension must be applied to the combination of all the MeasureDimensions considered as a joint [[variable>>doc:sdmx:Glossary 2\.1.Statistical variable.WebHome]]{{footnote}}E.g., if in the data structure there exist 3 Dimensions C,D,E having the role of MeasureDimension, they should be considered as a joint MeasureDimension Z=(C,D,E); therefore when the description says “each possible value Cj of the MeasureDimension …” it means “each possible combination of values (Cj, Dk, Ew) of the joint MeasureDimension Z=(C,D,E)”.{{/footnote}}.
++In [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] 2.1 the MeasureDimension was a subclass of DimensionComponent like [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] and TimeDimension. In the current [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] version, this subclass does not exist anymore, however a [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] can have the role of [[measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] [[dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] (i.e. a [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] that contributes to the identification of the [[measures>>doc:sdmx:Glossary 2\.1.Measure.WebHome]]). In [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] 2.1 a DataStructure could have zero or one MeasureDimensions, in the current version of the standard, from zero to many [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] may have the role of [[measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] [[dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]]. Hereinafter a [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] that plays the role of [[measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] [[dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] is referenced for simplicity as “MeasureDimension“, i.e. maintaining the capital letters and the courier font even if the MeasureDimension is not anymore a class in the [[SDMX Information Model>>doc:sdmx:Glossary 2\.1.SDMX Information Model.WebHome]] of the current [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] version. For the sake of simplicity, the description below considers just one [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] having the role of MeasureDimension (i.e., the more simple and common case). Nevertheless, it maintains its validity also if in the DataStructure there are more [[dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] with the role of MeasureDimensions: in this case what is said about the MeasureDimension must be applied to the combination of all the MeasureDimensions considered as a joint [[variable>>doc:sdmx:Glossary 2\.1.Statistical variable.WebHome]]{{footnote}}E.g., if in the data structure there exist 3 Dimensions C,D,E having the role of MeasureDimension, they should be considered as a joint MeasureDimension Z=(C,D,E); therefore when the description says “each possible value Cj of the MeasureDimension …” it means “each possible combination of values (Cj, Dk, Ew) of the joint MeasureDimension Z=(C,D,E)”.{{/footnote}}.
  Among other things, the Pivot method provides also backward compatibility with the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] 2.1 data structures that contained a MeasureDimension.
--If applied to [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] structures that do not contain any MeasureDimension, this method behaves like the Basic (% style="color:#e74c3c" %)mapping(%%) (see the previous paragraph).
++If applied to [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] structures that do not contain any MeasureDimension, this method behaves like the Basic mapping (see the previous paragraph).
--The [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] structures that contain a MeasureDimension are (% style="color:#e74c3c" %)mapped(%%) as described below (this (% style="color:#e74c3c" %)mapping(%%) is equivalent to a pivoting operation):
++The [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] structures that contain a MeasureDimension are mapped as described below (this mapping is equivalent to a pivoting operation):
  * A [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] simple [[dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] becomes a [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] (simple) identifier and a [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] TimeDimension becomes a [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] (time) identifier;
--* Each possible [[Code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] Cj of the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] MeasureDimension is (% style="color:#e74c3c" %)mapped(%%) to a [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] [[Measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]], having the same name as the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] [[Code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] (i.e. Cj); the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] [[Measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] Cj is a new [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] [[component>>doc:sdmx:Glossary 2\.1.Component.WebHome]] even if the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] data structure has not such a [[Component>>doc:sdmx:Glossary 2\.1.Component.WebHome]];
--* The [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] MeasureDimension is not (% style="color:#e74c3c" %)mapped(%%) to [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] (it disappears in the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] Data Structure);
--* The [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] [[Measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] is not (% style="color:#e74c3c" %)mapped(%%) to [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] as well (it disappears in the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] Data Structure);
--* An [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] DataAttribute is (% style="color:#e74c3c" %)mapped(%%) in different ways according to its AttributeRelationship:
--** If, according to the [[SDMX>>doc:sdmx:Glossary 2\.1.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 2\.1.Statistical data and metadata exchange.WebHome]] DataAttribute becomes a [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] [[Attribute>>doc:sdmx:Glossary 2\.1.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 2\.1.Data set.WebHome]] (% style="color:#e74c3c" %)level(%%)), or if it refers to a set (or a group) of [[dimensions>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] which does not include the MeasureDimension;
--** Otherwise, if, according to the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] AttributeRelationship, the values of the DataAttribute depend on the MeasureDimension, the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] DataAttribute is (% style="color:#e74c3c" %)mapped(%%) to one [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] [[Attribute>>doc:sdmx:Glossary 2\.1.Attribute.WebHome]] for each possible [[Code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] of the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] MeasureDimension. By default, the names of the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] [[Attributes>>doc:sdmx:Glossary 2\.1.Attribute.WebHome]] are obtained by concatenating the name of the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] DataAttribute and the names of the correspondent [[Code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] of the MeasureDimension separated by underscore. For example, if the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] DataAttribute is named DA and the possible [[Codes>>doc:sdmx:Glossary 2\.1.Code.WebHome]] of the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] MeasureDimension are named C1, C2, …, Cn, then the corresponding [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] [[Attributes>>doc:sdmx:Glossary 2\.1.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 2\.1.Attribute.WebHome]] through [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] operators).
--** Like in the Basic (% style="color:#e74c3c" %)mapping(%%), the resulting [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] [[Attributes>>doc:sdmx:Glossary 2\.1.Attribute.WebHome]] are considered as dependent on all the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] identifiers (i.e. "at data point / observation (% style="color:#e74c3c" %)level(%%)"), because [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] does not have the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] notion of [[Attribute Relationship>>doc:sdmx:Glossary 2\.1.Attribute relationship.WebHome]].
++* Each possible [[Code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] Cj of the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] MeasureDimension is mapped to a [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] [[Measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]], having the same name as the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] [[Code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] (i.e. Cj); the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] [[Measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] Cj is a new [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] [[component>>doc:sdmx:Glossary 2\.1.Component.WebHome]] even if the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] data structure has not such a [[Component>>doc:sdmx:Glossary 2\.1.Component.WebHome]];
++* The [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] MeasureDimension is not mapped to [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] (it disappears in the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] Data Structure);
++* The [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] [[Measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] is not mapped to [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] as well (it disappears in the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] Data Structure);
++* An [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] DataAttribute is mapped in different ways according to its AttributeRelationship:
++** If, according to the [[SDMX>>doc:sdmx:Glossary 2\.1.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 2\.1.Statistical data and metadata exchange.WebHome]] DataAttribute becomes a [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] [[Attribute>>doc:sdmx:Glossary 2\.1.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 2\.1.Data set.WebHome]] level), or if it refers to a set (or a group) of [[dimensions>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] which does not include the MeasureDimension;
++** Otherwise, if, according to the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] AttributeRelationship, the values of the DataAttribute depend on the MeasureDimension, the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] DataAttribute is mapped to one [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] [[Attribute>>doc:sdmx:Glossary 2\.1.Attribute.WebHome]] for each possible [[Code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] of the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] MeasureDimension. By default, the names of the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] [[Attributes>>doc:sdmx:Glossary 2\.1.Attribute.WebHome]] are obtained by concatenating the name of the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] DataAttribute and the names of the correspondent [[Code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] of the MeasureDimension separated by underscore. For example, if the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] DataAttribute is named DA and the possible [[Codes>>doc:sdmx:Glossary 2\.1.Code.WebHome]] of the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] MeasureDimension are named C1, C2, …, Cn, then the corresponding [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] [[Attributes>>doc:sdmx:Glossary 2\.1.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 2\.1.Attribute.WebHome]] through [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] operators).
++** Like in the Basic mapping, the resulting [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] [[Attributes>>doc:sdmx:Glossary 2\.1.Attribute.WebHome]] are considered as dependent on all the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] identifiers (i.e. "at data point / observation level"), because [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] does not have the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] notion of [[Attribute Relationship>>doc:sdmx:Glossary 2\.1.Attribute relationship.WebHome]].
--The summary (% style="color:#e74c3c" %)mapping(%%) table of the "pivot" (% style="color:#e74c3c" %)mapping(%%) from [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] for the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] data structures that contain a MeasureDimension is the following:
++The summary mapping table of the "pivot" mapping from [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] for the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] data structures that contain a MeasureDimension is the following:
  (% style="width:739.294px" %)
--|(% style="width:335px" %)**[[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]]**|(% style="width:400px" %)**[[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]]**
++|(% style="width:335px" %)**SDMX**|(% style="width:400px" %)**VTL**
  |(% style="width:335px" %)[[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]]|(% style="width:400px" %)(Simple) Identifier
  |(% style="width:335px" %)TimeDimension|(% style="width:400px" %)(Time) Identifier
  |(% style="width:335px" %)MeasureDimension & one [[Measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]]|(% style="width:400px" %)One [[Measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] for each [[Code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] of the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] MeasureDimension
@@ -257,9 +257,9 @@
  [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] MeasureDimension
  )))
--Using this (% style="color:#e74c3c" %)mapping(%%) method, the [[components>>doc:sdmx:Glossary 2\.1.Component.WebHome]] of the data structure can change in the conversion from [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] and it must be taken into account that the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] statements can reference only the [[components>>doc:sdmx:Glossary 2\.1.Component.WebHome]] of the resulting [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] data structure.
++Using this mapping method, the [[components>>doc:sdmx:Glossary 2\.1.Component.WebHome]] of the data structure can change in the conversion from [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] and it must be taken into account that the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] statements can reference only the [[components>>doc:sdmx:Glossary 2\.1.Component.WebHome]] of the resulting [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] data structure.
--At observation / data point (% style="color:#e74c3c" %)level(%%), calling Cj (j=1, … n) the j^^th^^ [[Code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] of the MeasureDimension:
++At observation / data point level, calling Cj (j=1, … n) the j^^th^^ [[Code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] of the MeasureDimension:
  * The set of [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] observations having the same values for all the [[Dimensions>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] except than the MeasureDimension become one multi-[[measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] Data Point, having one [[Measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] for each [[Code>>doc:sdmx:Glossary 2\.1.Code.WebHome]] Cj of the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] MeasureDimension;
  * The values of the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] simple [[Dimensions>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]], TimeDimension and DataAttributes not depending on the MeasureDimension (these [[components>>doc:sdmx:Glossary 2\.1.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 2\.1.Validation and transformation language.WebHome]] (simple) Identifiers, (time) Identifier and [[Attributes>>doc:sdmx:Glossary 2\.1.Attribute.WebHome]].
@@ -272,22 +272,22 @@
  The Basic_A2M and Pivot_A2M behaves respectively like the Basic and Pivot methods, except that the final [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] [[components>>doc:sdmx:Glossary 2\.1.Component.WebHome]], which according to the Basic and Pivot methods would have had the role of [[Attribute>>doc:sdmx:Glossary 2\.1.Attribute.WebHome]], assume instead the role of [[Measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]].
--Proper [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] features allow changing the role of specific [[attributes>>doc:sdmx:Glossary 2\.1.Attribute.WebHome]] even after the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] (% style="color:#e74c3c" %)mapping(%%): they can be useful when only some of the DataAttributes need to be managed as [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] [[Measures>>doc:sdmx:Glossary 2\.1.Measure.WebHome]].
++Proper [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] features allow changing the role of specific [[attributes>>doc:sdmx:Glossary 2\.1.Attribute.WebHome]] even after the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary 2\.1.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 2\.1.Validation and transformation language.WebHome]] [[Measures>>doc:sdmx:Glossary 2\.1.Measure.WebHome]].
  === 12.3.4 Mapping from VTL to SDMX data structures ===
  ==== 12.3.4.1 Basic Mapping ====
--The main (% style="color:#e74c3c" %)mapping(%%) method **from [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] to [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]]** is called **Basic **(% style="color:#e74c3c" %)mapping(%%) as well.
++The main mapping method **from [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] to [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]]** is called **Basic **mapping as well.
  This is considered as the default (% style="color:#e74c3c" %)mapping(%%) method and is applied unless a different method is specified through the VtlMappingScheme and VtlDataflowMapping classes.
--The method consists in leaving the [[components>>doc:sdmx:Glossary 2\.1.Component.WebHome]] unchanged and maintaining their names and roles in [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]], according to the following (% style="color:#e74c3c" %)mapping(%%) table, which is the same as the basic (% style="color:#e74c3c" %)mapping(%%) from [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]], only seen in the opposite direction.
++The method consists in leaving the [[components>>doc:sdmx:Glossary 2\.1.Component.WebHome]] unchanged and maintaining their names and roles in [[SDMX>>doc:sdmx:Glossary 2\.1.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 2\.1.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]], only seen in the opposite direction.
--(% style="color:#e74c3c" %)Mapping(%%) table:
++Mapping table:
  (% style="width:470.294px" %)
--|(% style="width:262px" %)**[[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]]**|(% style="width:205px" %)**[[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]]**
++|(% style="width:262px" %)**VTL**|(% style="width:205px" %)**SDMX**
  |(% style="width:262px" %)(Simple) Identifier|(% style="width:205px" %)[[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]]
  |(% style="width:262px" %)(Time) Identifier|(% style="width:205px" %)TimeDimension
  |(% style="width:262px" %)[[Measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]]|(% style="width:205px" %)[[Measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]]
@@ -295,21 +295,21 @@
  If the distinction between simple identifier and time identifier is not maintained in the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] environment, the [[classification>>doc:sdmx:Glossary 2\.1.Statistical Classification.WebHome]] between [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] and TimeDimension exists only in [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]], as declared in the relevant DataStructureDefinition.
--Regarding the [[Attributes>>doc:sdmx:Glossary 2\.1.Attribute.WebHome]], because [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] considers all of them "at observation (% style="color:#e74c3c" %)level(%%)", the corresponding [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] DataAttributes should be put "at observation (% style="color:#e74c3c" %)level(%%)" as well, unless some different information about their AttributeRelationship is otherwise available.
++Regarding the [[Attributes>>doc:sdmx:Glossary 2\.1.Attribute.WebHome]], because [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] considers all of them "at observation level", the corresponding [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] DataAttributes should be put "at observation level" as well, unless some different information about their AttributeRelationship is otherwise available.
--Note that the basic mappings in the two directions (from [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] and vice-versa) are (almost completely) reversible. In fact, if a [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] structure is (% style="color:#e74c3c" %)mapped(%%) to a [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] structure and then the latter is (% style="color:#e74c3c" %)mapped(%%) back to [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]], the resulting data structure is like the original one (apart for the AttributeRelationship, that can be different if the original [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] structure contains DataAttributes that are not at observation (% style="color:#e74c3c" %)level(%%)). In reverse order, if a [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] structure is (% style="color:#e74c3c" %)mapped(%%) to [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] and then the latter is (% style="color:#e74c3c" %)mapped(%%) back to [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]], the original data structure is obtained.
++Note that the basic mappings in the two directions (from [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] to [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] and vice-versa) are (almost completely) reversible. In fact, if a [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] structure is mapped to a [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] structure and then the latter is mapped back to [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]], the resulting data structure is like the original one (apart for the AttributeRelationship, that can be different if the original [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] structure contains DataAttributes that are not at observation level). In reverse order, if a [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] structure is mapped to [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] and then the latter is mapped back to [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]], the original data structure is obtained.
  As said, the resulting [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] definitions must be compliant with the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] consistency rules. For example, the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] [[DSD>>doc:sdmx:Glossary 2\.1.Data structure definition.WebHome]] must have the AttributeRelationship for the DataAttributes, which does not exist in [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]].
  ==== 12.3.4.2 Unpivot Mapping ====
--An alternative (% style="color:#e74c3c" %)mapping(%%) method from [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] to [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] is the **Unpivot **(% style="color:#e74c3c" %)mapping(%%).
++An alternative mapping method from [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] to [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] is the **Unpivot **mapping.
--Although this (% style="color:#e74c3c" %)mapping(%%) method can be used in any case, it makes major sense in case the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] data structure has more than one [[measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] [[component>>doc:sdmx:Glossary 2\.1.Component.WebHome]] (multi-[[measures>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] structure). This is used to support the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] 2.1 case of a MeasureDimension or any other [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] acting as a list of [[Measures>>doc:sdmx:Glossary 2\.1.Measure.WebHome]], under the assumptions explained in section “Pivot (% style="color:#e74c3c" %)Mapping(%%)”.
++Although this mapping method can be used in any case, it makes major sense in case the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] data structure has more than one [[measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] [[component>>doc:sdmx:Glossary 2\.1.Component.WebHome]] (multi-[[measures>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] structure). This is used to support the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] 2.1 case of a MeasureDimension or any other [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] acting as a list of [[Measures>>doc:sdmx:Glossary 2\.1.Measure.WebHome]], under the assumptions explained in section “Pivot Mapping”.
  The multi-[[measures>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] structures are converted to [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] [[Dataflows>>doc:sdmx:Glossary 2\.1.Dataflow.WebHome]] having an added MeasureDimension, which disambiguates the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] multiple [[Measures>>doc:sdmx:Glossary 2\.1.Measure.WebHome]], and a new [[Measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] in place of the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] ones, containing the values of the [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] [[Measures>>doc:sdmx:Glossary 2\.1.Measure.WebHome]].
--The **unpivot** (% style="color:#e74c3c" %)mapping(%%) behaves like follows:
++The **unpivot** mapping behaves like follows:
  * like in the basic (% style="color:#e74c3c" %)mapping(%%), a [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] (simple) identifier becomes a [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] [[Dimension>>doc:sdmx:Glossary 2\.1.Dimension.WebHome]] and a [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] (time) identifier becomes a [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] TimeDimension (as said, a [[measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] identifier cannot exist in multi-[[measure>>doc:sdmx:Glossary 2\.1.Measure.WebHome]] [[VTL>>doc:sdmx:Glossary 2\.1.Validation and transformation language.WebHome]] structures);
  * a MeasureDimension [[component>>doc:sdmx:Glossary 2\.1.Component.WebHome]] called "measure_name" is added to the [[SDMX>>doc:sdmx:Glossary 2\.1.Statistical data and metadata exchange.WebHome]] DataStructure;