RE: JW11: single scope

OK, I can live with this.  I think the specification should explicitly
mention that multiple search scopes are intentionally not supported.

- Jim

> Jim Whitehead:
>
> "If I want to do a search only on the src/module2/ and src/module3/
> hierarchies, I would have to submit two DASL requests in the current
> proposal."
>
> Yes, that's correct. This will probably be generalized on
> the next release of DASL. The famous criterion "is it useful
> without this feature" applied to this situation resulted in
> limiting the scope list to one element.
>
> Your other comments below don't lead me to want to revise this
> version of the protocol draft.
>
> Alan Babich
>
> -----Original Message-----
> From: Jim Whitehead [mailto:ejw@ics.uci.edu]
> Sent: Tuesday, July 20, 1999 2:52 PM
> To: Babich, Alan; 'DASL'
> Subject: RE: JW11: single scope
>
>
>
> > If I remember correctly, we deliberately decided to limit the
> > scope list to one element for the first version to avoid defining and
> > debating three valued elimination -- the obvious
> straightforward extension
> > of three valued logic used in other industry standards to handle
> > cross-repository queries.
>
> I was thinking more in terms of performing a query on, say, multiple
> hierarchies on the same server, making the assumption that all of the
> hierarchies contained resources with the same properties.
>
> For example, if I have some resources set up as follows:
>
>         src/
>         src/module1/
>         src/module2/
>         src/module3/
>
> If I want to do a search only on the src/module2/ and src/module3/
> hierarchies, I would have to submit two DASL requests in the current
> proposal.
>
> > That is necessary, because the query
> > schemas of multiple repositories don't have to be identical, and
> > the issue of handling queries that are partially defined arises
> > immediately.
>
> I agree, but I don't see a query directed to a single DASL arbiter running
> into this problem.  Perhaps if a DASL search arbiter were sitting
> on top of
> a DMA interface this would occur...
>
> > First issue: Do you want your query to be defined on the intersection
> > of the query schemas, or their union? That must be specified.
> > The intersection may be too small to be useful, especially for
> > repositories that don't implement QSD. The union case must
> > obviously handle queries that are only partially defined on its
> > constituent repositories.
>
> Since all DAV resources have to support a known set of predefined
> properties, doing a search on the intersection can be quite useful.
>
> - Jim
>

Received on Monday, 16 August 1999 20:09:37 UTC