You are right. It is easy to broadcast the same query, but the
difficulty is to create different queries for different servers. When a
user can't create the right query because of the differences between
servers, it would be nice  when  servers that support additional
response blocks are able to  provide these to the user.

Theo


>>> [log in to unmask] 20-4-04 20:51:13 >>>
> Currently it is not easy with SRU/W to broadcast the same query to
many
> SRU/W servers because one has to take into account all the
differences
> between different servers. Especially in metasearching I think it
would

I disagree.

It's easy to send the same semantic search in SRW to servers because
of
the significantly better structure and ease of understanding at all
levels of CQL compared to RPN attribute vectors.

Any metasearch client will have to take into account differences
between
some servers because not everyone creates records and databases in the
same way.  This is to be expected and cannot be 'standardized'.
It has nothing to do with SRW/U and compared to metasearch using
Z39.50
(at the query level at least) CQL is a large step forwards.

One other point I'm going to make is that in terms of computational
resource usage, SRW servers will be much lighter weight than Z39.50.
Many
of the overload issues that content providers have now with Z will be
alleviated by exposing SRW instead.  Why?  Because, no offence to any
Z implementors and this applies to our server just the same, Z39.50
servers are not well written in terms of high load situations.
Apache/IIS
on the other hand -have- to stand up to hundreds or thousands of
concurrent users every day all over the web.
As Ralph said at the 2001 ZIG:  "I don't want to have to write another
server, I want to let the guys at Apache do it for me."

> 1) Who would support a proposal for extending SRU/SRW with such an
> operation?
> 2) Should this be done via a new x-parameter or via a new operation?

As ever, I don't think this is a useful extension, but you're welcome
to
do it in the privacy of your own implementation using the extension
mechanisms within SRW already.

Rob

And yes, I'll be at the meeting later this week.
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