[TABLE] Re: TAP1.0 Comments

[Guy Rixon]

On 12 Aug 2009, at 09:45, Alberto Micol wrote:

>
> On 12 Aug 2009, at 00:16, Doug Tody wrote:
>
>> On Tue, 11 Aug 2009, Alberto Micol wrote:
>>>
>>> Regarding the above described symmetry, there might be a problem  
>>> in par 2.3.5.
>>>
>>> In par 2.3.5 there is a table upload example to specify how a  
>>> multi-position search might work using PQL.
>>> (btw, it is a pity there is no dedicated paragraph to the multi- 
>>> position search topic).
>>>
>>> The last sentence of 2.3.5, regarding multi-position queries, reads:
>>> "it is up to the service to pick up suitable position column(s)  
>>> from the uploaded tables",
>>>
>>> What if the uploaded table has got multiple positions (as in the  
>>> case of a result of a TAP join)?
>>> Wouldn't that  break the ability to upload a TAP result to another  
>>> TAP service?
>>>
>>> It would be much better to allow the user to specify which  
>>> coordinate pair to use.
>>
>> The issue of multi-position queries is really a PQL issue;
>
> mmmh... are you saying that I cannot upload my table of favourite  
> objects to search for,
> and use the full power of ADQL to specify more constraints?
>
> Alberto

You can, but you would then have to express the position constraints  
in ADQL too.

You can't mix PQL and ADQL in the same query. At least, TAP makes no  
stipulation that
all implementations support this, so you can't assume it for an  
arbitrary service, and
doesn't specify a way to denote support in a capability.

Of course, if POS, SIZE and REGION were defined to be part of TAP  
rather than part of PQL then
we could have more freedom and function.

Cheers,
Guy