Subject: [CODE4LIB] exploiting z39.50

From: Eric Lease Morgan <[email-masked]>
Date: Fri, 8 May 2009 14:12:39 -0400

How might I go about exploiting Z39.50 to extract specific MARC  
records from a library catalog?

More precisely, I am trying to download sets of MARC records from  
remote library catalogs destined for a sort of union catalog. I see  
each of these records being identified with a specific string in a  
local note or local subject field. This string might be "CRRA", and my  
question is three-fold:

   1. What MARC field/subfield might I put this string?
   2. How would I go about getting the string indexed?
   3. How might I go about querying the server for records with this  
string?

For example, I might put CRRA in 599 $a. I would cross my fingers  
hoping this field gets indexes, and I might be able to search for it  
like this [1]:

  @attr 1=63 2=3 3=3 4=2 5=100 6=1 CRRA

Am I on the right track?

[1] http://www.collectionscanada.gc.ca/bath/tp-bath2.23-e.htm#b

-- 
Eric Morgan

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From: "Ray Denenberg, Library of Congress" <[email-masked]>
Date: Fri, 8 May 2009 14:46:55 -0400

From: "Eric Lease Morgan" <[email-masked]>
>   3. How might I go about querying the server for records with this 

I can at least talk about the third question.  There was work on a marc 
attribute set, though not completed.  If you look at the oid register at 
http://www.loc.gov/z3950/agency/defns/oids.html you'll see that the latest 
work on it (second draft) was in 2000, 
http://www.nlc-bnc.ca/iso/z3950/MARC_attribute_set_2.doc. So if someone 
actually wanted to put it to use it would have to be completed.

For SRU there is a complete marc context set, 
http://www.loc.gov/standards/sru/resources/marc-context-set.html.

--Ray

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From: Jonathan Rochkind <[email-masked]>
Date: Fri, 8 May 2009 15:08:37 -0400

I wonder how xID handles superceded OCLCnums, if it'll still succesfully 
find the right matches for you?

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From: Xiaoming Liu <[email-masked]>
Date: Fri, 8 May 2009 15:18:32 -0400

> find the right matches for you?

This is documented in
http://xisbn.worldcat.org/xisbnadmin/xoclcnum/api.htm#deleted

"Worldcat uses OCLC Control Number Cross-Reference to track deleted OCLC
numbers. When an OCLC number is deleted, it's still search-able from this
service. In the response, we use presentOclcnum to specify present OCLC
number. For example 2416076 was merged into 24991049, a request of the
deleted number 2416076 will return:

      <rsp xmlns="http://worldcat.org/xid/xoclcnum/" stat="ok">
      <oclcnum lccn="34025476" presentOclcnum="24991049">2416076</oclcnum>
      </rsp>

The presentOclcnum field is omitted when an OCLC number is active, so
request to current OCLC number 24991049 returns:

      <rsp xmlns="http://worldcat.org/xid/xoclcnum/" stat="ok">
      <oclcnum lccn="34025476" >24991049</oclcnum>
      </rsp>

Xiaoming

>> http://www.loc.gov/z3950/agency/defns/oids.html you'll see that the
>> latest work on it (second draft) was in 2000,

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From: Dana Pearson <[email-masked]>
Date: Sat, 9 May 2009 06:29:01 -0500