In that case you can return the records with a few selected fields, but
still do it in a standard record schema. I'd recommend simple Dublin
Core http://www.loc.gov/standards/sru/resources/dc-schema.html
e.g.

<srw_dc:dc xmlns:srw_dc="info:srw/schema/1/dc-v1.1" xmlns:dc="http://purl.org/dc/elements/1.0" id="gb133engms93">
    <dc:title>My Title</dc:title>
    <dc:creator>My Author</dc:creator>
</srw_dc:dc>

You could make this the default so that it is what gets returned by a
first search, and only carry out mapping to marcxml when explicitly
requested to (i.e. when recordSchema=marcxml is in the parameters)

Hope this helps
John


On Wed, 2009-10-14 at 10:44 +0100, Eran gi wrote:
> Hmmm... I might have messed up with the terms. Please bear with me,
> making my first steps here.
>
>
> The protocol is actually SRU, not the old style z39.50. Sorry...
>
> > Date: Wed, 14 Oct 2009 10:01:26 +0100
> > From: [log in to unmask]
> > Subject: Re: Returning a "preview" of the searchRetrieve results,
> instead of the full items
> > To: [log in to unmask]
> >
> > The standard way to do this is using element-sets. When you want to
> > show a list of summary records, request element-set "b" (brief), and
> > when you want to display a detailed record, request element-set "f"
> > (full).
> >
> > (By the way, Z39 is a working group within ANSI/NISO. There are
> other
> > Z39 standards, including Z39.2, MARC, and Z39.88, OpenURL. So it's a
> > very bad abbreviation to use for Z39.50.)
> >
> > 2009/10/14 Eran gi <[log in to unmask]>:
> > > Hello,
> > >
> > > In our application's built-in search engine, the search process
> includes 3
> > > steps:
> > > 1. The user executes a query
> > > 2. A "preview" of the results is presented, containing the items'
> titles,
> > > authors etc.
> > > 3. When an item is selected, the complete record is presented to
> the user.
> > > This way, the system does the relatively expensive task of
> gathering the
> > > complete item record only upon demand.
> > >
> > > The z39.50 protocol consist of only two steps: searching and
> getting a list
> > > of complete records. Due to the way our database is designed,
> converting our
> > > native format to marcxml, for instance, requires an export
> operation, which
> > > is quite heavy. Having to go through with that before the user can
> even be
> > > sure the results are indeed what she was looking for could be
> quite a
> > > burden.
> > >
> > > The only solution I could think of is supplying a non-standard
> record schema
> > > in which only a few selected fields would be returned. Then, if
> the user
> > > would like to get the complete records, one of the standard
> schemas would be
> > > used. Does this comply with the spirit of z39? will the average
> client
> > > understand the idea? is there a better way?
> > >
> > > Thanks,
> > > Eran
> > >
>
>
>
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