Changes for page 12 Validation and Transformation Language (VTL)
Last modified by Helena on 2025/09/10 11:19
Summary
-
Page properties (1 modified, 0 added, 0 removed)
Details
- Page properties
-
- Content
-
... ... @@ -255,7 +255,10 @@ 255 255 At observation / data point level, calling Cj (j=1, … n) the j^^th^^ Code of the MeasureDimension: 256 256 257 257 * The set of SDMX observations having the same values for all the Dimensions except than the MeasureDimension become one multi-measure VTL Data Point, having one Measure for each Code Cj of the SDMX MeasureDimension; 258 -* The values of the SDMX simple Dimensions, TimeDimension and DataAttributes not depending on the MeasureDimension (these components by definition have always the same values for all the observations of the set above) become the values of the corresponding VTL (simple) Identifiers, (time) Identifier and Attributes. 258 +* The values of the SDMX simple Dimensions, TimeDimension and DataAttributes not depending on the MeasureDimension (these components by definition have always the same values for all the observations of the set above) become the values of the corresponding VTL (simple) 259 + 260 +Identifiers, (time) Identifier and Attributes. 261 + 259 259 * The value of the Measure of the SDMX observation belonging to the set above and having MeasureDimension=Cj becomes the value of the VTL Measure Cj 260 260 * For the SDMX DataAttributes depending on the MeasureDimension, the value of the DataAttribute DA of the SDMX observation belonging to the set above and having MeasureDimension=Cj becomes the value of the VTL Attribute DA_Cj 261 261 ... ... @@ -348,7 +348,7 @@ 348 348 The mapping table is the following: 349 349 350 350 (% style="width:689.294px" %) 351 -|(% style="width:344px" %) **VTL**|(% style="width:341px" %)**SDMX**354 +|(% style="width:344px" %)VTL|(% style="width:341px" %)SDMX 352 352 |(% style="width:344px" %)(Simple) Identifier|(% style="width:341px" %)Dimension 353 353 |(% style="width:344px" %)(Time) Identifier|(% style="width:341px" %)TimeDimension 354 354 |(% style="width:344px" %)Some Measures|(% style="width:341px" %)Measure ... ... @@ -408,16 +408,22 @@ 408 408 409 409 SDMX Dataflow having INDICATOR=//INDICATORvalue //and COUNTRY=// COUNTRYvalue//. For example, the VTL dataset ‘DF1(1.0.0)/POPULATION.USA’ would contain all the observations of DF1(1.0.0) having INDICATOR = POPULATION and COUNTRY = USA. 410 410 411 -In order to obtain the data structure of these VTL Data Sets from the SDMX one, it is assumed that the SDMX DimensionComponents on which the mapping is based are dropped, i.e. not maintained in the VTL data structure; this is possible because their values are fixed for each one of the invoked VTL Data Sets{{footnote}}If these DimensionComponents would not be dropped, the various VTL Data Sets resulting from this kind of mapping would have non-matching values for the Identifiers corresponding to the mapping Dimensions (e.g. POPULATION and COUNTRY). As a consequence, taking into account that the typical binary VTL operations at dataset level (+, -, *, / and so on) are executed on the observations having matching values for the identifiers, it would not be possible to compose the resulting VTL datasets one another (e.g. it would not be possible to calculate the population ratio between USA and CANADA).{{/footnote}}. After that, the mapping method from SDMX to VTL specified for the Dataflow DF1(1.0.0) is applied (i.e. basic, pivot …).414 +In order to obtain the data structure of these VTL Data Sets from the SDMX one, it is assumed that the SDMX DimensionComponents on which the mapping is based are dropped, i.e. not maintained in the VTL data structure; this is possible because their values are fixed for each one of the invoked VTL Data Sets{{footnote}}If these DimensionComponents would not be dropped, the various VTL Data Sets resulting from this kind of mapping would have non-matching values for the Identifiers corresponding to the mapping Dimensions (e.g. POPULATION and COUNTRY). As a consequence, taking into account that the typical binary VTL operations at dataset level (+, -, *, / and so on) are executed on the observations having matching values for the identifiers, it would not be possible to compose the resulting VTL datasets one another (e.g. it would not be possible to calculate the population ratio between USA and CANADA).{{/footnote}}. After that, the mapping method from SDMX to VTL specified for the Dataflow DF1(1.0.0) is applied (i.e. 412 412 413 - In the example above, forall the datasets of the kind ‘DF1(1.0.0)///INDICATORvalue//.//COUNTRYvalue//’,the dimensions INDICATOR and COUNTRY would be dropped so that the data structure of all the resulting VTL Data Sets would havetheidentifier TIME_PERIOD only.416 +basic, pivot …). 414 414 418 +In the example above, for all the datasets of the kind 419 + 420 +‘DF1(1.0.0)///INDICATORvalue//.//COUNTRYvalue//’, the dimensions INDICATOR and COUNTRY would be dropped so that the data structure of all the resulting VTL Data Sets would have the identifier TIME_PERIOD only. 421 + 415 415 It should be noted that the desired VTL Data Sets (i.e. of the kind ‘DF1(1.0.0)/// INDICATORvalue//.//COUNTRYvalue//’) can be obtained also by applying the VTL operator “**sub**” (subspace) to the Dataflow DF1(1.0.0), like in the following VTL expression: 416 416 417 417 ‘DF1(1.0.0)/POPULATION.USA’ := 425 + 418 418 DF1(1.0.0) [ sub INDICATOR=“POPULATION”, COUNTRY=“USA” ]; 419 419 420 420 ‘DF1(1.0.0)/POPULATION.CANADA’ := 429 + 421 421 DF1(1.0.0) [ sub INDICATOR=“POPULATION”, COUNTRY=“CANADA” ]; 422 422 423 423 … … … ... ... @@ -433,6 +433,7 @@ 433 433 This is equivalent to the application of the VTL “sub” operator only to the identifier //INDICATOR//: 434 434 435 435 ‘DF1(1.0.0)/POPULATION.’ := 445 + 436 436 DF1(1.0.0) [ sub INDICATOR=“POPULATION” ]; 437 437 438 438 Therefore the VTL Data Set ‘DF1(1.0.0)/POPULATION.’ would have the identifiers COUNTRY and TIME_PERIOD. ... ... @@ -463,8 +463,11 @@ 463 463 ‘DF2(1.0.0)/GDPPERCAPITA.USA’ <- expression11; ‘DF2(1.0.0)/GDPPERCAPITA.CANADA’ <- expression12; 464 464 465 465 … … … 476 + 466 466 ‘DF2(1.0.0)/POPGROWTH.USA’ <- expression21; 478 + 467 467 ‘DF2(1.0.0)/POPGROWTH.CANADA’ <- expression22; 480 + 468 468 … … … 469 469 470 470 As said, it is assumed that these VTL derived Data Sets have the TIME_PERIOD as the only identifier. In the mapping from VTL to SMDX, the Dimensions INDICATOR and COUNTRY are added to the VTL data structure on order to obtain the SDMX one, with the following values respectively: