Re: Comments on V1.1 - Future of VOTable (flame bait sigh)

From: Martin Hill <mch-at-roe.ac.uk>
Date: Thu, 8 Apr 2004 16:27:21 +0100


Certainly VOTable will be around for a while.

We can and should continue to develop VOTable in minor ways to be more useful, particularly to improve the metadata section. We can and should insist that any VO-enabled service return results in VOTable form.

However let us please please not make it the long term defacto standard for astronomical data! Such a decision could easily kill the VO! All you will have at the end of it is a verbose, limited structure, VO-specific data metaformat - a bit like FITS but less well known, with less tools and libraries, and requiring more processor time, bandwidth and disk storage. The big advantage of VOTable over FITS is a well-defined metadata area and human-readability; the former necessary for the VO, the latter useful for debugging but let's face it, is mostly useful because of the lack of VOTable tools.

I'm not talking about a few minor problems with VOTable; I'm talking about some fundamental problems in taking a good first attempt at representing 2d astronomical tables in XML, and then trying to use it as the basic representation of all astronomical data.

We do not have to wait for the data modellers to produce a final, complex model before we can start building standard data formats around suitable parts. These new formats can be written with modern industry-standard XML tools in mind, instead of having to write our own. Indeed as I have said before, we could and should be building specific data models and formats for particular data sets *now* instead of following this particular dead end.

In summary: of course, keep tweaking VOTable to keep it up to date with UCD developments, registry resources, etc. But let's not start assuming it is suitable for general use for the long term, just because it's all anyone's managed to agree on so far. Instead let's focus on agreeing *suitable* data representations for data sets.

etc...

MC

(I expect you were all expecting this... :-)

On Thursday 08 April 2004 1:50 pm, Anita Richards wrote:
> > > * re 2: Data Model
> > > this section should begin with a note that the VOTable
> > > representation of a Data Model will be superseded by the work of the
> > > IVOA Data Model group.
> >
> > I basically disagree -- I do not see VOTable as a temporary patch
> > until the (necessarily complex) final data model comes up.
>
> I too think that VOTable is here to stay for a decade or so. The use of
> VOTable for metadata is being designed-in to major new instruments e.g.
> ALMA, and for the rest of us more modest data providers, not
> to mention tool-designers, it has been a major step forwards to get a
> large proportion of the community to go over to something as standard and
> useful as VOTable. It may not be perfect but sometimes you ahve to work
> with what you ahve got. The community is no better resourced than we are
> on average, probably worse; we should minmise the transoformations we
> require. It is vital that our prototypes can be turned into real global
> tools now and incrementally or we will not serve real needs.
>
> I realise that there are things which can only be done using VOTable
> alongside clunky fixes, and Tony's viewpoint is that using VOTable cuts us
> off from efficient applications of other functionality. However I think
> this is an 80:20 situation and VOTable solves the important 80%...
>
> Maybe this question should be posted to the dm mailing list? As an
> apprentice dm person, I think that we very much need unifying standards
> based on real models and I don't see anything which is better than
> VOTable, and real data providers certainly can't wait (or be given
> excuses to delay). Using the FITS analogy, for a long time FITS was
> nearly standard but people used the lack of formal agreement (now reached)
> to produce all kinds of abominations which ignorred the keywords which
> already did have general consensus. If we start dissing VOTable the
> practical consequence will be more sloppy metadata, not better, in the
> life-times of most of our projects. But am I just a paranoid
> conservative?
>
> cheers
> a
>
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
> Dr. Anita M. S. Richards, AVO Astronomer
> MERLIN/VLBI National Facility, University of Manchester,
> Jodrell Bank Observatory, Macclesfield, Cheshire SK11 9DL, U.K.
> tel +44 (0)1477 572683 (direct); 571321 (switchboard); 571618 (fax).

-- 
Martin Hill
Astrogrid/AVO, ROE
Tel: 07901 55 24 66
Received on 2004-04-08Z17:28:23