TAP and the Data Models
2021-10-28, 08:00–09:30, Grand Ballroom

TAP is one of the big achievements of the VO. This protocol gives any relational database a high level of interoperability thanks to several IVOA standards:
- The TAP_SCHEMA : a description of the tables, their columns and the way they can be joined.
- ADQL: a query language, subset of SQL, with some astronomy-specific features
- UWS: a specification for a REST API to be used to handle service requests
These features provide a common way to discover the content of TAP services and to query them.
This works very well with relational data and we propose to investigate the possibility for TAP services to map searched data on data models. Indeed several data models have been developed by IVOA in order to tackle the complexity of the relationships between astronomical data features. Among those we can quote Photometry Data Model, Coordinates, Measurements, Transforms or MANGO that is well suited to describe source properties and relations to some datasets representing these sources. TAP services are able to host complex data bound with joins but the standard still misses important features to serve real model instances:
- A meta-data endpoint telling which models are available per table
- Storage of model meta-data into the TAP_SCHEMA
- Storage of coordinate frames in the TAP service
- Mechanism specifying the model on which the requested data must be mapped
- Mechanism returning multi-table responses for complex objects
- Preservation of model annotations in uploaded tables
The purpose of the BoF is to discuss the relevance of enabling TAP services to deal with Data Models and to refine the functionalities required to implement such a capability.

We will be able to present a proof of concept based on the VOLLT framework that can annotate on the fly query responses on two archive tables using the MANGO data model. Any other contribution and point of view on this topic will be is welcome and helpful to lift up and enrich the debate .


Building accessible and friendly user interfaces, Other

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