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    Record Match/Overlay for OCLC records

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    • Article Type: General
    • Product: Aleph
    • Product Version: 17.01

    Description:
    We have just begun loading records from OCLC and find that, if we update or correct a bib record in OCLC that had previously been imported into Aleph, when we import the updated record it creates a new Aleph record rather than overlaying the old Aleph record. I think I must have one or more tables set up incorrectly, but I can't see where the problem lies. I do notice that, while we have tables called tab_match_script and tab_match_script_rlin, there is no table tab_match_script_oclc though there is a program argument tab_match_script_oclc in tab_match. I was unable to find a tab_match_script_oclc in a17_1.

    Resolution:
    It appears that your OCLC matching routine is not doing what you need it to do. In your $data_tab/tab_match, you have two live entries for OCLC matching. Most likely, the first one is the only one being used. It specifies a match on the 010 or LCCN field. That's a pretty shaky match point, as many records, particularly for specialized collections, don't have LCCNs in them. The second OCLC match entry, which is probably not being used, specifies to use the tab_match_script_oclc script for matching, but that file doesn't exist. There is also an OCLC2 entry, but I don't think that would be used at all.

    So, I recommend that you eliminate (either comment out or delete) the first live OCLC entry (for T-010) and use the second one. To use it, you need to create a file named tab_match_script_oclc. The following is one from another site, and I think it has pretty good logic. It matches first on the 035 field, which is the OCLC number. If that fails, it tries to match on the ISBN or the ISSN if either is present. You could add a line for the 010 if wanted to do that, but probably the other three are sufficient in themselves. Once you have the file in place and have made the changes to tab_match, you'll need to restart at least the oclc_server, and possibly the pc_server as well, using util w. The tab_match_script_oclc looks like this:

    01 match_doc_gen 1 stop TYPE=IND,TAG=035##,SUBFIELD=a,CODE=035
    01 1+ goto 02
    01 0 goto 02
    02 match_doc_gen 1 stop TYPE=IND,TAG=020##,SUBFIELD=a,CODE=ISBN
    02 1+ goto 03
    02 0 goto 03
    03 match_doc_gen 1 stop TYPE=IND,TAG=022##,SUBFIELD=a,CODE=ISSN
    03 1+ goto 05
    03 0 goto 05
    05 1+ stop
    05 0 stop

    • Article last edited: 10/8/2013