Re: Qualifier Combinations in CQL (Was: Bib-2 and the DC-Lib)

> Date: Tue, 23 Apr 2002 15:07:35 -0400
> From: "LeVan,Ralph" <levan@oclc.org>
> 
> Mike, you're scaring me!

Why, thank you!

> > 	util:creator,bib2:personal,dclib:agentDetail=Kernighan
> 
> We've not agreed to any syntax like that and the sense at the ZIG
> meeting was to not allow it.  But, what that would mean in SRW and
> what I think you think it means are two different things.
>
> I think you mean for that to be a combination of attributes from
> multiple Attribute Sets to generate an access point.  We don't do
> that in SRW.

Ah -- I see.  Well you've got me there.

But doesn't this point up a fundamental shortcoming in CQL as
currently conceived, namely, that it's not benefitted from the lessons
of the attribute architecture in terms of refining an access point
from one set with qualifiers from another?  That's the thing that
makes interoperability between cross-domain and bibliographic servers
and clients possible in the AA world -- surely CQL doesn't want to
discard that?

> We use indexes which are externally predefined combinations of
> attributes from any attribute sets.

We should perhaps take this over the ZING list if it's not of general
interest, but this concerns me.  For all that Z39.50 in general, and
the attribute architecture in particular, has real complexity, that
complexity gives rise to real power.  I very much understand and
sympathise with the drive to simplify, but there are two kinds of
complexity: real and apparent.  SRW and CQL more surely should slice
of apparent complexity whenever it can, but when it starts to slice of
"real complexity", so that interoperability functionality goes with
it, then we need to be very very sure that we're not compromising the
result.

(Sorry if this has all been gone over before, BTW.)

> The only possible interpretation of that query in SRW is that you
> want Kernighan as either a util:creator or a bib2:personal (huh?) or
> a dclib:agentDetail (huh?).

:-)

 _/|_	 _______________________________________________________________
/o ) \/  Mike Taylor   <mike@miketaylor.org.uk>   www.miketaylor.org.uk
)_v__/\  "What's it like?" -- Eric Idle, Monty Python's Flying Circus.

Received on Wednesday, 24 April 2002 06:24:04 UTC