VO Data Modeling Language Specification

Current WD:

• VO-DML: a consistent modelling language for IVOA data models (docx, pdf)

Schema files providing normative definitions vor valid VO-DML/XML files can be found here:

• XML schema (XSD) for main structure of document: https://volute.googlecode.com/svn/trunk/projects/dm/vo-dml/xsd/vo-dml.xsd
• Schematron for extra rules that cannot be (easily) implemented in XSD: https://volute.googlecode.com/svn/trunk/projects/dm/vo-dml/xsd/vo-dml.sch.xml

[GL 2014-04-25: I will try to keep track of comments from the mailing list on this page

A set of data models created according to the specification can be found on volute as well in the dm/vo-dml/models folder. Of special relevance for this specification are

• ivoa: a core model defining various primitive types as well as quantity types. This model should be reused by all other models.
• photdm-alt: a versison of the PhotDM data model, should be synchronized with that spec.
• source: TOY model for describing astronomical sources. ONLY used in the VO-DML and UTYPE specs for illustrating the various modelling and mapping concepts, NOT proposed as a real source data model!

We have made a first superficial pass at porting other IVOA data models to VO-DML, in particular characteriation, stc, simdm. These can be used as starting points for a more formal IVOA DM effort to create VO-DML representations for all models, but such an effort MUST include domain experts for those models, i.e. likely the original modellers.

Many of these models have been created from a UML definition using an XSLT script available in the xslt sub-folder. For each model an HTML documentation file has been generated from the vo-dml/xml representation using another xslt script. These can be executed using appopriate ttargets in the ant build.xml file. This also contains a target for validating vo-dml/xml files, which is especially useful for such files written by hand.

Please read the README.txt for a first draft of a documentation of the structure of the vo-dml folder on volute and and hints how to use the ant build.xml script for the various XSLT scripts. This documentation will be copied on this page over time.