Yuji,
I haven't had time to go through your entire talk, but there is one point that I would like to raise.
You are suggesting that the coordinate frame can be omitted under
certain consitions.
I think that is a bad idea, for the same reasons why you were arguing
that a table alias should always be specified: users get confused when
it is sometimes needed, sometimes not. And it is a very small effort
to just include it to begin with, especially as I suspect most users
will not fashion the queries themselves, but through an interface. I
have no problems with the interface presenting the user with defaults,
but it should include the frame explicitly in the query.
The larger picture is that we hope to include more than galactic and extra-galactic astronomers to the VO. In the past week we have had discussions with solar people on coordintes. Invariably, if you allow defaults in queries, people are going to assume that the default is what *they* think is the most "natural" choice. That has the potential for large-scale confusion and it is much better to state from the beginning that a frame needs to be specified.
Yuji SHIRASAKI wrote:
>
> Dear VOQLers,
>
> I have uploaded a slide that will be presented at the
> VOQL meeting. Please look at the following URL:
>
> http://www.ivoa.net/internal/IVOA/InterOpMay2006VOQL/VOQL-YujiShirasaki-ver1.pdf
>
> It is still under preparation, but I wellcome your comments and/or
> questions on the contents, especially from those who cannot attend
> the meeting.
>
> It is worthwhile to start the discussion even before the meeting.
>
> I also uploaded update versions of ADQL and ADQL-Core schema.
>
> See you soon.
>
> Yuji Shirasaki.
>
Arnold H. Rots Chandra X-ray Science Center Smithsonian Astrophysical Observatory tel: +1 617 496 7701 60 Garden Street, MS 67 fax: +1 617 495 7356 Cambridge, MA 02138 arots-at-head.cfa.harvard.edu USA http://hea-www.harvard.edu/~arots/ --------------------------------------------------------------------------Received on 2006-05-14Z15:10:10