JSON type in ADQL and TAP

[Molinaro, Marco]

Dear all,

(I try to add a few bits, despite the discussion
already has some complexity and it might sound a
repetition)

Il giorno lun 11 set 2023 alle ore 09:39 Pierre Le Sidaner <
pierre.lesidaner at obspm.fr> ha scritto:

> On 11/09/2023 09:05, Markus Demleitner wrote:
> > On Fri, Sep 08, 2023 at 05:28:39PM +0200, Gregory MANTELET wrote:
> >> This topic could probably be discussed in more details during a DAL
> running
> >> meeting or during an interop meeting.
> >
> > I think a discussion session on this -- specifically, JSON in
> > VOTable, not JSON in ADQL, which I consider much less problematic --,
> > perhaps with one or two 5-minute introductory talks, would be a
> > great thing at this or the next interop.  If it doesn't fit in
> > Tucson, perhaps we can have a smaller side meeting during ADASS time?
>

I'm fully in for whatever solution for the discussion
gets decided upon. It can also be a pre-Interop
plus a multiple-joined-group session at the
Interop.

The only point I disagree a bit is: seeing
'JSON in ADQL less problematic', but I'd be
happy if it's so.


> > So, for now I'd be in favour of inline JSON (if at all).  But I'm
> > afraid it won't be just an xtype; I'm sure we'll have to define at
> > least to some extent what clients are expected to do with the
> > list/dict structures they'd be parsing out of such columns.
>

I agree with this.

W.r.t. "weak column metadata" I have a similar issue
in a project I'm working on.
There, multiple sets of tabular data are being stored
as JSONB in higher abstraction level table cells.
Having clients consume those structures (that PostgreSQL
can easily access) requires some pre-knowledge of the
context/content and, so far, no way to do that in our
standards.

So, I'd be happy to start discussion there, I welcomed
Igor's emails since it reports similar concerns.


> I know that JSON IN/INSTEAD of VOTable is a recurrent discussion in
> IVOA. At least in Apps
>

JSON & VO is really multi-faceted.
I considere "JSON in VOTable" quite different w.r.t.
"JSON instead of VOTable".

I feel Igor's question falls more on the first area.

It seem that you propose a more generic subject, and if I understand the
> apps part of what you proposed. There is that idea to have vectors
> objects and how to handle them.
> If JSON format is a good non binary format, it should fit in discussion
> at Interop Apps.
> We have to clearly start with simple case.
>

I do feel this would be better in an Apps managed
but DAL participated session (DALI at least is involved).

Should we make it a plenary?
Or keep it more technical (i.e. also a parallel can work)?
Up to coordinators to discuss this.

For me, personally, I'd like to see discussion
on 3 aspects (at least):
- JSON in VOTable
- JSON binding for VOTable as a model
- JSON for "non-data" responses (e.g. UWS request/responses)

Of course, not all in one session.

Cheers
    Marco


>
> Regards
> Pierre
> --
> -------------------------------------------------------------------------
>                            Pierre Le Sidaner
>                       Observatoire de Paris - PSL
>
> Directeur de la Direction Informatique de l'Observatoire
> Directeur technique de Paris Astronomical Data Centre
> tel : 01 40 51 20 82
> 77 Av Denfert Rochereau 75014 Paris
>
> mailto:pierre.lesidaner at observatoiredeparis.psl.eu
> http://dio.obspm.fr  http://padc.obspm.fr
>
> --------------------------------------------------------------------------
>
>

-- 
Marco Molinaro
INAF - Istituto Nazionale di AstroFisica
Osservatorio Astronomico di Trieste
email marco.molinaro at inaf.it
tel. [+39] 333 33 20 564 [also Telegram]
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