A dedicated task-force of the SDMX Technical Working Group (TWG) submits the new specification of a Validation and Transformation Language (VTL) for public review. The review period extends until 8th November 2014 in order to allow time for consolidation of a final version at the end of 2014. Feedback is welcome.
At the end of 2012, the SDMX Secretariat requested the TWG to start a new work package on “Expressions and Calculations” aimed at allowing the definition and the exchange of validation and transformation rules, based on the generic framework for defining mathematical expressions already existing in the SDMX information model. To make such framework fully operational, a standard language for defining validation and transformation rules (set of operators, their syntax and semantics) should be adopted, while appropriate IT formats for exchanging such rules – and web services to store and retrieve them – should be designed.
The intention is to provide a language which is usable by statisticians to express logical validation rules and transformations on data, whether described as a dimensional table or as unit-record data. Although a work-product of SDMX, the VTL language is based on the GSIM data model and should be usable with other standards as well. The present draft for public review also provides (in its part 1) a formal description of data validation at business level against which information models can be mapped.
VTL – part 1: Validation and Transformation Language (General Description)
VTL – part 2: Validation and Transformation Language (Library of Operators)
Please send your comments to the SDMX Technical Working Group (SDMX-TWG) at twg@sdmx.org. Each email message should contain only a limited set of numbered – and possibly homogeneous – comments and should contain the elements indicated in the attached comment log.