[Ops] Test queries from registry

[Markus Demleitner]

Dear Ops,

First: Thanks, Mark, for pointing out the SimpleDALRegExt test
queries, which, as you say, are what out to be used to construct test
queries for S*AP (including SIAv2) services...

On Tue, Jun 08, 2021 at 11:12:53AM +0100, Mark Taylor wrote:
> The relevant information is in the "testQuery and the Query Type"
> subsections of SimpleDALRegExt
> (https://www.ivoa.net/documents/SimpleDALRegExt/)
> which explains what test query information is registered for SCS/SIA/SSA,
> and in Appendix A of RegTAP (https://www.ivoa.net/documents/RegTAP/)
> which gives (the non-obvious) details of how to extract this
> information from the rr.res_detail table.

...and in particular for the RegTAP queries (apologies for making it
a bit tricky to pick them out of the various tables).


But because we're talking about test queries and authors of
validators (who might want to chime on when such protocols are
designed) read this, let me mention that *future* protocols allowing
GET requests should preferably use the per-interface testQueryString
that was introduced in VOResource 1.1 (cf.
https://ivoa.net/documents/VOResource/20180625/REC-VOResource-1.1.html#tth_sEc3.2.2,
the vr:Interface type).  

The advantage here is mainly that no registry extension is required
to define test queries (and that per-interface test queries
potentially allow finer-grained validation).  The next version of
RegTAP will also map this information into rr.interface in order to
make it easily accessible.

Again, this is for future protocols; I do not expect that the
existing SimpleDALRegExt registry extensions will move this way, so
looking up test queries for them in the way shown by Mark will
certainly remain the Right Thing for a long time to come.

            -- Markus