[CATALOGUE]Starting Data Model Subgroup

[Arnold Rots]

That's correct, it's a set of derived data - often in the past, for
practical reasons, printed as a table.
But now that we are much more flexible in choosing our publication
forms, there may be links to data objects from which parameter values
may be derived on the fly and according to the user's specifications.
Or, for that matter, the publication form may be graphical, or a
spreadsheet.  In other words, we now have the ability to create truly
interactive catalogs and it would be a pity to constrain ourselves by
what a catalog(ue) used to look like.
And, by the way, STC contains space-time coordinate metadata elements
specifically intended for catalog records.

  - Arnold

Kirk Borne wrote:
> A catalogue is not a table, generally speaking.  It can be expressed 
> as a table or as a set of many tables, but that is not the point.  
> A catalogue is a set of derived data: derived from imaging, spectral, 
> event lists, time series, interferometric, or other types of data.
> The data model must describe not only the structure of the "table", 
> including attributes and values, but also inheritance, provenance,
> semantics, error columns, and more (units, formats, column-column 
> relationships, table-table relationships).  
> 
> We will *not* have to rebuild all this stuff that we already have,
> if we simply recognize the work of the former-ADC group, which started 
> building the catalogue model already, as expressed in "dataset"...
> 
>     http://xml.gsfc.nasa.gov/#dataset
> 
> Furthermore, UCDs already provide the semantics.
> 
> - Kirk
> 
> 
> > From owner-dm at eso.org  Mon Jul 26 14:51:05 2004
> > From: "Roy Williams" <roy at caltech.edu>
> > To: "Jonathan McDowell" <jcm at head.cfa.harvard.edu>, <dm at ivoa.net>
> > Subject: Re: [CATALOGUE]Starting Data Model Subgroup
> > Date: Mon, 26 Jul 2004 11:37:34 -0700
> > 
> > > The VOTable
> > > is a serialization of a simple table, but an astronomical catalog
> > > is more than a table - it will have extra standard metadata linking
> > > the sources to their parent observations and extraction algorithms,
> > > for instance.
> > 
> > You will use inheritance, I hope. Not just build everything from scratch?
> > 
> > We already have a simple example. A ConeSearchResponse inherits from the
> > VOTable model. It is a VOTable that must have RA, Dec, and ID attributes.
> > 
> > We can also inherit curatedTable from Table by adding the VOResource
> > curation information.
> > 
> > Please tell me you are not going to rebuild all this stuff that we already
> > have....?
> > 
> > Roy
> > 
> > 
> 
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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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