Re: Limiting a Search by URL

I don't agree with Mike.

Two points:

(1)The original semantics of bib-1 use attribute 1032 was: "A persistent identifier,
or     Doc-ID, assigned by a server, that uniquely identifies a document on that server."
That was amended however (1997) to "An identifier or Doc-ID, assigned by a server, that
uniquely identifies a document on that server. May or may not be persistent. May be, for
example, a URL."  The notable change is the last sentence. (The other change is from
"persistent" to "may or may not be persistent" but that's not relevant to this
discussion.) It explicitly allows urls.

(2) The Z39.50 url definition is very explicit that the doc-id is to be used with a
structure attribute of Urx; when this combination is used, the 1032 semantics becomes:
"The term is a document identifier, for example, an identifier extracted from a Z39.50
URL."  Thus the local indentifier interpretation holds when Urx is supplied as a structure
attribute, but doesn't necessarily hold otherwise.

So I don't think we need another attribute, I think 1032 is suitable for your purpose,
particularly so if we're limiting this to bib-1. If we were crafting a solution based on
attribute architecture we'd surely come up with something better, but if we're confined to
bib-1 then we have to live with its limitations.

--Ray



Chris Peterson/Amigos wrote:

> So . . . should I ask the ZIG for another use attribute specifically for
> URLs?  All ideas and comments are appreciated.
>
> Chris
>
> ----- Forwarded by Chris Peterson/Amigos on 02/05/2003 11:53 AM -----
>
>                       Mike Taylor
>                       <mike@seatbooker.n        To:       peterson@amigos.org
>                       et>                       cc:       ldix@loc.gov,
>                       Sent by: Mike             Subject:  Re: Limiting a Search by URL
>                       Taylor
>                       <mike@basingstoke.
>                       tecc.co.uk>
>
>
>                       01/28/2003 09:45
>                       AM
>
>
>
> > Date: Mon, 27 Jan 2003 12:06:33 -0600
> > From: "Chris Peterson/Amigos" <peterson@amigos.org>
> >
> > At first, I did think about using 1209 for this search.  I checked
> > with Ray to see what he thought.  He said that 1209 was added
> > specifically for searching URNs, not URLs.  Ray can probably provide
> > more detail on this if you want.  But he suggested that 1032 might
> > be a better choice.
>
> Sorry to butt in to this one so late in the day, but 1032 is
> absolutely NOT a suitable access point for this.  It is intended for
> opaque identifiers generated by the database itself, and supplied (for
> example) in the localControlNumber (1,14) element of GRS-1 record so
> that the application can retrieve the same record again later.  Its
> use for this purpose is explicitly described in RFC 2056 (Uniform
> Resource Locators for Z39.50) which is available at
>  http://lcweb.loc.gov/z3950/agency/defns/rfc2056.html
>
> I quote from section 2 ("Some Basic Concepts") of that document:
>
>  A special case of a Z39.50 search is a "known-item"
>  search, when a client intends that a search identify a
>  single, known database record, or "document" (for
>  purposes of illustration, assume that a database
>  record corresponds to a document), and further, the
>  client knows an identifier for the document that can
>  be used to effect this known-item search.  In this
>  case, this identifier is often referred to as a
>  document identifier, or "docid".
>
> And from section 4 ("The Z39.50 Retrieval URL"):
>
>  The Z39.50 Retrieval URL is intended to allow a Z39.50
>  session to be used as a transparent transfer mechanism
>  to retrieve a specific information object.  A Z39.50
>  client uses information in the URL to formulate a
>  Search Request.
>  [...]
>  -  The docid is placed into a type-1 query, as the
>     single term, in the general format (tag 45), using
>     the Bib-1 attribute set, with a Use attribute value
>     of docid, and a structure attribute of URx.  The
>     docid string is server-defined and completely
>     opaque to the client.
>
> And from the appendix "Examples of Z39.50 URLs":
>
>  z39.50r://melvyl.ucop.edu/mags?elecworld.v30.n19
>
> (in which the docId is "elecworld.v30.n19")
>
>  _/|_  _______________________________________________________________
> /o ) \/  Mike Taylor   <mike@miketaylor.org.uk>   www.miketaylor.org.uk
> )_v__/\  "Christianity is not about having all the answers, but
>   knowing someone who does" -- Harvey Thompson.
>
> --
> Now available: _Child's Play_, my wife Fiona's CD of kids' music.
> Download free sample tracks; buy on-line or by mail-order.
>  http://www.pipedreaming.org.uk/childsplay/

Received on Thursday, 6 February 2003 15:52:45 UTC