Date:         Wed, 10 Jul 2002 15:59:24 -0400
Reply-To:     "Z39.50 Next-Generation Initiative" <[log in to unmask]>
Sender:       "Z39.50 Next-Generation Initiative" <[log in to unmask]>
From:         "LeVan,Ralph" <[log in to unmask]>
Subject:      Re: multiple schemas
Comments: To: "Z39.50 Next-Generation Initiative" <[log in to unmask]>
Content-Type: text/plain; charset="iso-8859-1"

The simplest solution would be for the diagnostic to say what schemas might
work.

Ralph

> -----Original Message-----
> From: Ray Denenberg [mailto:[log in to unmask]]
> Sent: Wednesday, July 10, 2002 3:50 PM
> To: [log in to unmask]
> Subject: Re: multiple schemas
>
>
> Suppose a server has a default schema, say its DC, and many records
> are available in DC, but a few records are not available in DC but
> are available in other schemas.
>
> So a client asks for 3  records, gets back record 1 in DC, record 2
> in DC, and a surrogate for record 3, because it's not available in
> DC. Suppose that client really wants that third record.  What does he
> do?  Explain will tell you the default schema, and it may tell you
> other supported schemas, but it won't tell you schemas supported for
> that record.
> Should SRW provide a solution to this scenario?
>
> Perhaps we can develop a simple "record Metadata" schema, RMS, that
> would include all the schemas supported for a record, maybe recordId
> and date of last update, etc.  Then a client could specify RMS as the
> schema, get metadata for the requested records, and then request the
> desired record in one of the supported schemas.
>
> Would this be a good idea?
>
> --Ray
>
>
> "LeVan,Ralph" wrote:
>
> > But (a) is not amenable to explain.  It says that the behavior is
> > unpredictable, learn to like it.  I don't.
> >
> > Ralph
> >
> > > -----Original Message-----
> > > From: Ray Denenberg [mailto:[log in to unmask]]
> > > Sent: Wednesday, July 10, 2002 10:46 AM
> > > To: [log in to unmask]
> > > Subject: multiple schemas
> > >
> > >
> > > "LeVan,Ralph" wrote:
> > >
> > > > I'm unhappy with the opinion that not specifying a schema
> > > might result in
> > > > records from multiple schemas being returned.  Servers
> > > should be expected to
> > > > specify their default schema (through explain) and return
> > > all records in
> > > > that schema when an explicit schema has not been specified.
> > >
> > > What are the semantics of omitting the schema name in a
> > > request? Is it:
> > >
> > > (a) give me each record in whatever schema is available (or
> > > the best, if there
> > > is more than one), or;
> > > (b) I don't know what's the default schema but give me all
> > > records in that
> > > schema; or
> > > (c) I know what your default schema is; I'm omitting it
> > > because I'm lazy. But I
> > > want all the records in that schema.
> > >
> > > If it's (c) then you're right.  (b) doesn't make sense -- it
> > > assumes that the
> > > client is prepared for multiple schemas so why limit it to
> > > one.  If it's (a)
> > > then I dissagree.
> > >
> > > --Ray
> > >
>