TAPVizieR

[LANDAIS Gilles (OBS)]

Hello IVOA members ,

Following the interop meeting discution about TAP 1.1.
VizieR expects some arrangements on the TAP protocol concerning the tapschema output. 

Due to the important volumetry (~25,000 table , ~ 300,000 columns), the web resource /tables of TAPVizieR provides the schema without the columns descriptions.
This output enables web applications like TAPHandle to work with TAPVizieR with a reasonable size of VOTable.

Currently, TAPVizieR provides a non-standard REST URL to get the full table description (with columns). The output URL uses the same XML schema than the standard resource /tables (VODataService/1.1).

Example:
http://tapvizier.u-strasbg.fr/TAPVizieR/tap/tables
http://tapvizier.u-strasbg.fr/TAPVizieR/tap/tables/II/246/out

Currently, only TAPHandle works with this proposal.

The TAPVizieR tables TAP_SCHEMA.tables and TAP_SCHEMA.columns are queriable and fully compliant with the standard. However the common way to retrieve the schema using the /tables URL is required for VO-software which connect different TAP services.

We agree with the proposal (Markus Demleitner) which consists to accept empty tables (without columns) and to provide another URL dedicated by table to have the full description (and this is the precisely what VizieR provides today).

However, if this proposal isn't endorsed; we could imagine something (more clean?) like to add a <url>http://....</url> in the <table> description.

For example: (not implemented today in VizieR)
<table type="base_table">
  <name>vbig.J/AJ/139/1808/refs</name>
  <url>http://tapvizier.u-strasbg.fr/TAPVizieR/tap/tables/J/AJ/139/1808/refs</url>
  <description>References</description>
</table>


Gilles landais