> -----Original Message-----
> From: Alan Kent [mailto:[log in to unmask]]
> Sent: Sunday, September 22, 2002 10:11 PM
> To: [log in to unmask]
> Subject: Re: index definitions
> This may be what this list agrees to, but personally I disagree
> with this point. To me one of the main potential benefits of SRW
> is to get away from the current vagueness of Bib-1 etc attributes.
> I think SRW should define clear semantics that should be possible
> for different implementations to map on to Bib-1 etc. But not
> everyone agrees on what Bib-1 attributes mean, so how can you
> come up with a single SRW definition if mandates Bib-1 bindings?
> Hence I prefer mandating semantics of the SRW queries, then
> providing *suggested* Bib-1 etc bindings. Maybe the new attribute
> set stuff is better here, but SRW relying on agreement as to
> what Bib-1 means is doomed to failure I suspect.
There are a number of issues being raised here, so lets try to untangle
First, it is critical that we have some mechanism to transmit the semantics
of the indexes. When I say that I have a SubjectHeading index, what does
that mean? Is there some way that I can clue a client in that it is a MeSH
subject index? The new attribute architecture was about just that. It
provides the mechanism to explain the rich semantics of an index. I want to
use that mechanism somehow. There is no point in having all these tools and
then miscommunicate that the Title index in my heraldry database doesn't
have document titles in it.
Our IndexSet definitions must find some way to use this mechanism to explain
the database. But, IndexSets only get defined once and then reused by the
rest of us.
The next problem is for a local site to define what subset of the IndexSet
it supports. I've been building a trivial variant of my IndexSet schema
called IndexSubset. It is identical to IndexSet, with an attribute on the
IndexSubset root element that points to the IndexSet that it subsets. The
rest of the IndexSubset just lists the indexes that are locally supported.
I am also using the IndexSubset to provide the mapping from Indexes to
z39.50 attributes. That mapping should not be mandatory in the schema and
can be ignored by any client that wants to. I do that so that I can use the
file to configure my code, not to provide semantics to the client. It can
get the semantics of the indexes from the original IndexSet.
Hopefully, with these clarifications, we can stop talking about the admitted
weaknesses of Bib-1.