On Thu, 2005-11-24 at 13:55 +0000, Mike Taylor wrote:
> > Date: Thu, 24 Nov 2005 14:03:02 +0000
> > From: Rob Sanderson <[log in to unmask]>
> > If you want others to search your database, then how will they know
> > what your 999 field means? Equally, how will they know if your
> > database is UKMARC, USMARC, FINMARC etc with all of their cute
> > little variations? How are they going to know that you've put notes
> > in 521a and 520d, but not 500a?
>
> Pish tish. These are merely problems to be solved, not reasons to
> declare the whole enterprise pointless. The bottom line is that we
> can't predict what people will want to use this for, so we shouldn't
> try to prescribe. "Mechanism, not policy".
> > How do I know that any given SRU interface is to a MARC database?
>
> Explain? Out-of-band agreement?
Let me rephrase my objections :)
There's nothing -wrong- with creating a marc format specific context set
with n thousand possible indexes corresponding to field + subfield, and
if there is an out-of-band agreement as to marc bibliographic profiles
(which there obviously are) then it's quite possible to use the context
set in the community where the agreement holds.
My objection is that it would be better to work out what is actually
wanted, rather than how it is stored, and create a context set that
would be useful outside of searching databases of marc records.
Then the answer to the original question is Yes, not only do we make it
easier, we make it that your users don't need to lug around a copy of
the marc bibliographic tables just to work out what to put in the search
field.
> > Also, SRU doesn't allow for the concept of a MARC database any more
> > than it allows for the concept of an XML database, a PDF database, a
> > JPG database or any other format.
>
> Sure it does. SRU doesn't say anything one way or the other on the
> subject, and nor it should.
The SRW/U model is that there is a collection of records, and the search
takes place over that collection. The format of those records is not
something which SRW/U cares about, so long as they can be expressed in
XML for retrieval. So my point is that as SRU doesn't have the concept
of a <format> database, it can't let the searcher know that it is a
<format> database.
Now you COULD have a database that conforms to a MARC profile, which
says that marcxml record schema and the marc context set must be
supported. But that doesn't preclude records being stored internally as
JPGs, OCRed and interpreted on the fly, then returned as marcxml, for an
extreme example.
Rob
--
Dr Robert Sanderson
Dept of Computer Science, University of Liverpool
Home: http://www.csc.liv.ac.uk/~azaroth/
Cheshire: http://www.cheshire3.org/
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