Scope of registry

[Clive Page]

On Wed, 5 Feb 2003, Arnold Rots wrote:

> So, it becomes a matter of degree.

Yes.  And I think the question of the granularity of information in the
Registry is a matter of debate.  It could be that different registries
have different policies.  The AstroGrid project has decided in principle
that a fine-grained registry is something to aim for (but maybe not in
version 1.0).  Others may have different aims.

It is clear that any query can be answered more definitively by firing
actual queries to each resource around the world, but the number of such
resources is getting quite large.  And we already know what happens when
you try that even on a limited scale: just use Astrobrowse to query the
set of sites they currently have listed and you find that even after a
minute or so not all the replies have come in.   A fine-grained registry
could, in principle, reduce the number of queries you need to send out
by quite a considerable factor (few observatories have observed more than
a tiny fraction of the sky, unless they have done systematic surveys).  I
think that would be nice to have, but I fully accept that it is not easy
to provide, so must be a matter for debate.  At least the debate has now
started.


-- 
Clive Page,
Dept of Physics & Astronomy,
University of Leicester,    Tel +44 116 252 3551
Leicester, LE1 7RH,  U.K.   Fax +44 116 252 3311