I forgot to send to the voql list.
Forwarded by Yuji SHIRASAKI <yuji.shirasaki-at-nao.ac.jp>
----------------------- Original Message ----------------------- From: Yuji SHIRASAKI <yuji.shirasaki-at-nao.ac.jp> To: Arnold Rots <arots-at-head.cfa.harvard.edu>Date: Sun, 14 May 2006 09:17:44 -0700 Subject: Re: slide of my talk
Dear Arnold,
Thank you your comments,
My suggestion on the coordinate frame is
You are saying that to include the frame in a query is a very small effort, but it is a little verbose for a user who know which frame is a defualt as he/she uses the table very frenquently.
And it is possible to inform at the user interface level which frame is a default, so user will no be confused if he/she uses the smart user interface.
In case of the simulation data, data might be queried based on the cartesian coordinate. The query might be someting like this:
Select *
From table
Where Region('CIRCLE 0 0 10')
This is a query searching data on XY plane withradius of 10 (arbitrary unit). In this case specifying the frame is almost meaningless.
Yuji Shirasaki
> 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.
>
> - Arnold
>
> 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/
> --------------------------------------------------------------------------
>
>
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-- Yuji SHIRASAKI <yuji.shirasaki-at-nao.ac.jp> __________ NOD32 1.1537 (20060514) Information __________ This message was checked by NOD32 antivirus system. http://canon-sol.jp/product/nd __________ NOD32 1.1537 (20060514) Information __________ This message was checked by NOD32 antivirus system. http://canon-sol.jp/product/nd --------------------- Original Message Ends -------------------- -- Yuji SHIRASAKI <yuji.shirasaki-at-nao.ac.jp>Received on 2006-05-14Z19:44:03