less required ADQL support [TAP-1.1]

[Marco Molinaro]

Hi all,
relaxing language on TAP data-side (i.e non TAP_SCHEMA) arose as an idea to
let people deploy TAP service in compliance with the spec but having
problems with ADQL for two main reasons:
- no SQL-like backends
- in-ADQL-geometry issues

However, apart from the technical problems discussed by Pat's and Markus'
mails yesterday, removing the ADQL recommendation from the TAP tableset
access will leave us with a spes where only the discovery of the tablesets
description is standard and afterwards, clients will require, possibly,
service-ad-hoc query building for each service deployed. I have to say I
don't like this at all.

So probably the "ADQL with respect to no SQL (whatever this means) and
geometry wrt various backends" should be moved out of TAP-1.1 way. I agree
with Markus and Pat that implementation should lead the way to this change.

Cheers,
    Marco

2015-09-29 21:24 GMT+02:00 Patrick Dowler <patrick.dowler at nrc-cnrc.gc.ca>:

>
> NoSQL was an example of the kind of thing this is about... and you could
> be right that the status quo is sufficient.
>
> My impression was that this was something that people outside the ivoa
> looking in were interested in and that it could make it clear that TAP was
> the solution they needed even without a RDBMS. Realising that you can get
> away with a subset of ADQL and do something valuable is something people
> usually discover by committing to TAP and then just trying to do it... but
> the big projects that CSP is interested in satisfying are maybe not likely
> to do that.
>
> Pat
>
>
> On 29/09/15 10:57 AM, Walter Landry wrote:
>
>> Patrick Dowler <patrick.dowler at nrc-cnrc.gc.ca> wrote:
>>
>>> I'm not very familiar with NoSQL query syntax, havig only hacked
>>> around with ElasticSearch in the context of log analysis... but the
>>> query language wouldn't be in TAP and it would surely take some time
>>> to make it a standard rather than custom lang...
>>>
>> What I am wondering is if there is a simple mapping from this NoSQL
>> query syntax to ADQL.  My impression is that the NoSQL syntax can be
>> expressed as a subset of ADQL.  In that case, you are not looking so
>> much for extension as for a way to subset.  I already have to subset
>> ADQL for my services.  When I gave a talk about this at Sesto, the
>> consensus was to let unsupported queries fail.  So I am not sure that
>> anything needs to be done now.
>>
>> Cheers,
>> Walter Landry
>>
>>
>>
>
> --
> Patrick Dowler
> Canadian Astronomy Data Centre
> National Research Council Canada
> 5071 West Saanich Road
> Victoria, BC V9E 2E7
>
> 250-363-0044 (office) 250-363-0045 (fax)
>
>
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