Obstap / about optional fields

[Juande Santander Vela]

Am 18/03/2011 um 05:06 schrieb Douglas Tody:

> TAP_SCHEMA.columns should fully describe the actual table, which *must*
> include all mandatory ObsCore fields, and which *may* include optional
> ObsCore fields or additional custom fields as defined by the data provider.

What about:

TAP_SCHEMA.columns should fully describe the actual table, which *must*
include all mandatory ObsCore fields, and which *may* include optional
ObsCore fields or additional custom fields as defined by the data provider.
A query using optional or custom fields has no guarantee of interoperability,
and ObsTAP services *must* return an error when columns not in 
TAP_SCHEMA.columns are referenced in the query.

I know it is redundant with the TAP protocol working, but because we are making an emphasis on interoperability in this document, I think it has to be stated.

--
Juande Santander Vela
Software Engineer, ALMA Archive Subsystem
Data Flow Infrastructure Department, Software Development Division
European Southern Observatory (Germany)

Denis Diderot: El primer paso hacia la filosofía es la incredulidad.