Public Review Announcement for the new VTL language, allowing the definition and exchange of validation and transformation rules

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 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.

Posted on 21 September 2014

Next SDMX Global Conference in September 2015

The next SDMX Global Conference will be held from 28 to 30 September 2015 at the United Nations Conference Centre in Bangkok. Beside the conference event itself, SDMX capacity building sessions will be organised. The conference agenda and the main topics of the conference will be announced latest at the beginning of 2015.

For any questions, please contact:
Posted on 16 September 2014

Public Review Announcement for new SDMX-JSON Data Exchange Format

The SDMX Technical Working Group (SDMX-TWG) has produced a new specification for the SDMX-JSON Data Message and submits it for public review.

JSON (JavaScript Object Notation) is a widely used standardised lightweight data-interchange format. The SDMX-JSON Data Message works together with the SDMX RESTful Web Services API. It will assist developers to write software that requests data responses in JSON from SDMX RESTful API and processes data and metadata in the JSON response. The current version of SDMX-JSON Data Message focuses on data visualisation and it supports all features of the SDMX RESTful API for data queries. SDMX RESTful API also supports reference metadata queries and structural metadata queries. These are not yet supported by the SDMX-JSON format.

The proposed format conforms to the JSON standard specification, and it supports the SDMX 2.1 Information Model. SDMX-JSON is streamable from a supporting web service in order to limit the amount of server resources. It should provide fast responses from a web service: few roundtrips, small message sizes and fast parsing. In addition, the format aims to ease the development of client applications with a simple but generic message structure that supports different types of data structures. The SDMX-JSON format may be used in a wide variety of programming languages and application programs. Testing and development of the format has focused on JavaScript applications running in web browsers.

Specification (authoritative): sdmx-json-data-message.pdf

HTML version of the specification, sample messages and informative JSON Schema:

The public review period for this specification extends until 31st October 2014 in order to allow time for implementation. Please send your comments to the SDMX Technical Working Group (SDMX-TWG) Each email message should contain only one comment. Feedback is welcome.

SDMX Expert Group Meeting 2014

The next SDMX Expert Group meeting will be held in Korea from 27 to 30 October 2014.

The meeting will focus on a number of areas, including:

  • exchange of statistical data and metadata actually taking place or being implemented between organisations;
  • work being carried out by the SDMX Technical and Statistical Working Groups;
  • software developments which take advantage of SDMX standards;
  • progress of SDMX standards, guidelines and tools, especially the content-oriented guidelines and the user guide. The role of the SDMX global registry, including use case examples;
  • the role of SDMX in standards-based modernisation of official statistics and related work being carried out by the High-Level Group for the Modernisation of Statistical Production and Services (HLG).

The meeting will also include a capacity building training session for statisticians and IT staff on how to implement an SDMX architecture for reporting and dissemination. The course will have a hands-on approach based on case studies related to the National Accounts and OECD STES (Short-Term Economic Statistics) data collections.

For more details, see

For further information and registration (registration form here) please contact