On Wednesday 07 March 2007 08:07, Doug Tody wrote:
> I do think we should distinguish between service metadata and dataset
> metadata. Also; didn't we already discuss this issue in telecon #1,
> and agree that querying table metadata is a function of the TAP interface,
> not the registry?
It came up as an issue in meeting #1, and FO posted some materials later on, but we did not come to a decision on whether metadata would be TAP-specific or simply VOResource(s).
Given the VOSI work, it seems pretty clear that the minimum effort for service metadata is to implement VOSI and return a VOResource for the service and it would be a shame to add a redundant TAP-specific service metadata mechanism,
As KA has reminded us, VOResource includes the capability to describe tables/datasets in some detail. I can't recall off hand if a service can have "child" tables/datasets. The "service for" does not (at least within UIs for creating registry entries) allow a single service to be the service for multiple dataset resources... but in any case, client software that access TAP services will already have to understand VOResource for the service metadata, so it again seems a shame to start thinking about other formats for table metadata.
As for table metadata itself being tabular, yeah that's probably true, but that's just another way of saying that one element type in the VOResource schema could be used for every table. I don't see it as a compelling reason to actually use a tabular format. Specifically, a table is just a way to look at a list of things where all the things have more or less the same structure (in this case list of some subtype of VOResource). We gain nothing by flattening that into a table.
bright and early tomorrow AM!!
-- Patrick Dowler Tel/Tél: (250) 363-6914 | fax/télécopieur: (250) 363-0045 Canadian Astronomy Data Centre | Centre canadien de donnees astronomiques National Research Council Canada | Conseil national de recherches Canada Government of Canada | Gouvernement du Canada 5071 West Saanich Road | 5071, chemin West Saanich Victoria, BC | Victoria (C.-B.)Received on 2007-03-07Z21:06:03