[Koha-devel] Solr and Z3950 server some news.

[Thomas Dukleth]

Reply inline:


On Tue, February 8, 2011 09:29, LAURENT Henri-Damien wrote:
> Hi
> We are getting a pretty nice working z3950 server for solr there.
> We are parsing RPN queries quite generally using a perl module
> Regexp::Grammars::Z3950::RPN
> and  RPN2Solr
> It is working quite well for simple usage (no exp1 or gils queries).

Hooray.  I greatly appreciate the work which BibLibre are doing for
supporting a Z39.50/SRU server using Solr/Lucene.

I note that the tests for SimpleServer using Solr/Lucene,
http://wiki.koha-community.org/wiki/SimpleServer_as_a_Z39.50/SRU_Server_Test_Queries_for_Koha_with_Solr/Lucene
, are as underpopulated as I had left them when I had to return to working
on a non-library project.  I took the time to write this message but I do
not have the time to completely populate the tests presently.

An important point of the few tests which I had included is that useful
functionality such as stemming should not be activated for a Z39.50/SRU
query unless specifically specified in the query.  In the case of copy
cataloguing, avoiding matches not specifically specified in the query is
very important.  Copy cataloguing use might need the opposite defaults to
what may most often benefit OPAC users.  If providing or avoiding various
forms of query expansion cannot be specified at query time for
Solr/Lucene, then we will need separate indexes with different defaults to
which queries may be directed as appropriate to the query.

>
> But at the moment it is serving right only marcxml and not ISO2709. I
> think we may have to try and determine exactly what type of data the
> Z3950 server is supposed to send to yaz-client when serving "MARC" data.

YAZ can convert between MARCXML and ISO 2709.  YAZ can perform both server
and  client functions.  I have not investigated precisely how to pass
MARCXML to YAZ for returning ISO 2709 as a server side function, although,
I have implemented such conversions as client functionality.  I do not
have time to investigate presently.

A Z39.50/SRU server should return records in accordances whatever record
syntaxes are specified as supported in the explain record.

Universal practise for Z39.50 server support of record syntax differs from
the standard in that a single Z39.50 server database is only expected to
support one record syntax.  Support for different record syntaxes over
Z39.50 is obtained in practise by providing different database targets on
the server which may be specified by the server as different database
names or the same database name but running on a different port.  In the
case of SRU, it is common for a single database target to support multiple
record syntaxes and return the record syntax which is specified in the SRU
query.

We are still a long ways from an ISO 2709 free world, therefore, a server
which only returns MARCXML is insufficient.  I note that the default Zebra
Z39.50 server configuration in Koha seems to only return MARCXML, but that
is a configuration deficiency.  We should also not presume that a
Z39.50/SRU client is using YAZ, although, a YAZ based client would be best
as the primary client for testing.

[...]


Thomas Dukleth
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