a high level language

[Kirk Borne]

Tony:  thanks for clarifying distinctions between workflow and query,
and between data services and functional services.  This is in fact
a distinction that Ed, Brian, and I discussed, but somehow I mangled
it in my example.  It is perhaps appropriate and prudent therefore
to keep those "functional" workflow actions separate from the VOQL's
query actions.

- Kirk


> From: "Tony Linde" <ael at star.le.ac.uk>
> To: <voql at ivoa.net>
> Subject: RE: a high level language
> Date: Mon, 24 Feb 2003 09:42:34 -0000
> 
> Hi Kirk,
> 
> Thanks for the reply.
> 
> > This query involves 
> > multi-wavelength data and multi-modal data (catalogs, spectra), and 
> > thereby the query must be parsed and distributed to 
> > appropriate data centers and maybe the data need to be 
> > shipped to some service (e.g., to generate line lists from 
> > optical spectra). 
> 
> This is what I assumed from Ed & Brian's document and why I raised the
> question. I can see that a *query* language might cover more than a
> simple single-dataset query, eg selecting from a join of distributed
> datasets with sub-selects etc. - the sort of thing you can do at the
> moment using SQL on the more advanced databases (though without the
> distributed bit).
> 
> However, when it comes to shipping intermediate data to another service
> for analysis, reduction etc., I would consider this to be *workflow*,
> requiring a separate description using a workflow language (as in the
> commercial world with the recent development of BPEL4WS).
> 
> > VOQL is a standardized language to capture scientist's 
> > queries to the distributed heterogeneous collections that 
> > comprise the VO. 
> 
> There I would agree. But the VO comprises more than data services, it
> includes functional services such as those to 'generate line lists'.
> Pushing the results of a query to such services, or using the results of
> a query in another, later, query amount to workflow construction.
> 
> There is a danger that, in trying to combine queries and workflow in a
> single language, we will overcomplicate the matter and reduce the chance
> of using or extending existing efforts in the development of query and
> workflow languages.
> 
> Cheers,
> Tony. 
> 
> > -----Original Message-----
> > From: Kirk Borne [mailto:borne at rings.gsfc.nasa.gov] 
> > Sent: 23 February 2003 22:01
> > To: ael at star.le.ac.uk
> > Cc: voql at ivoa.net
> > Subject: Re: a high level language
> > 
> > ...

+------------------------------------+-------------------------------------+
| Dr. Kirk D. Borne                  | mailto:Kirk.Borne at gsfc.nasa.gov     |
| Institute for Science & Technology, Raytheon (IST at R)                     |
| NASA Goddard Space Flight Center   |                                     |
| Astrophysics Data Facility         | Phone: 301-286-0696                 |
| Code 631                           |     or 301-286-2772:Kathy Starling  |
| Greenbelt, MD  20771               | FAX:   301-286-1771                 |
+------------------------------------+-------------------------------------+
  US Virtual Observatory:  http://us-vo.org/
  Staff page:     http://rings.gsfc.nasa.gov/~borne/bio_borne_kirk.html