table metadata and the registry

[Doug Tody]

On Tue, 8 May 2007, Tony Linde wrote (responding to Ray):

> 1. You've proposed returning a limited subset but in the same format as 
> VOResource table schema. Why do you stop at that level? Surely everything 
> within Capability describes the service. If we're going to pick an arbitrary 
> level, why not Capability or, better, VOResource? What is the issue with the 
> service returning *all* its metadata?

As noted earlier, for services there are at least four major classes
of "metadata" (resource, service, data collection including table,
dataset (which can also include table instances)).  Table metadata
is not service metadata, at the registry level my understanding is
that it is part of the description of a data collection.  A service
should be able to return table metadata, and this could be cached
in a fine-grained registry, but this will need to be done using
the database/table metadata query capabilities of the service.
Probably at the service level this will still resolve to a simple
static URL, however it is a distinct form of metadata and would
require a separate query.

 	- Doug