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CUNY Aleph Catalog Optimization Projects: Duplicate Bib Records

Project Documentation

Resolving Duplicate Bibliographic Records


In Alma, holdings and item (inventory) information of the second and subsequent duplicate bibliographic records from the same institution will not be visible in the Network Zone and in Primo. Below is the information related to duplicate records from Alma migration documentation.

There may be multiple matches of records (with a same OCLC# in 035) within the source file of a single institution when duplicate records with different source bibliographic IDs exist in the legacy system. This type of duplication within a single institution is not handled by migration, and in such cases, the duplicate (second and subsequent) matches will not show in the local IZ holdings list - only the first matched record will show up.

In other words, all of the duplicated records in the IZ are linked to the NZ record, but only one of the duplicate records show holdings in the NZ.

IZ -> NZ: all of the duplicate records in IZ link up to the NZ appropriately – that is, you can search for a record in the IZ and click up to the correct NZ record.

NZ -> IZ: if you search in the NZ for this title, the holdings from the first duplicate IZ record shows only as being held by that institution. The only way that all of the holdings for the institution to be shown from the NZ is if all IZ holdings are on a single bibliographic record.


It is strongly recommended that CUNY institutions resolve duplicate bibliographic records before the migration to avoid hidden holdings in NZ and in Primo.  OLS has identified duplicate bibliographic records. Lists of duplicate bibliographic records are posted on this LibGuide page. Each list contains Aleph IDs, Title (from 245) and OCLC# (from 035). Please note in most lists, only two Aleph ids are provided indicating there are at least two duplicate records for each title. Additional duplicate records might be found. We suggest you retrieve your duplicate records by using title search in Aleph to identify any additional duplicate records.


To resolve duplicate bibliographic records in Aleph, you’ll choose one record as target record and move holdings from other duplicate records (source record(s)) to the target record. When all the holdings and item records are moved to the target record, the source duplicate records should be deleted.

Here are the steps:

  1. Determine the record(s) (among duplicate records) to be the source record(s) and the record to be the target record.
  2. Unlink item(s) from holding on source record.
  3. Move holding from source record to target record by replacing the Aleph bib ID of the source HOL record in the LKR field $b with the bib ID of the target record.
  4. Move unlinked items from source to target by using the overview tree to drag the item(s) from the source record and drop them to the target record.
  5. Relink item(s) to holding of the target record.
  6. If merged item(s) are for the same location, then link the item to the original target holding record. Delete the holding record from the source.
  7. If source record has no holdings, items, orders, or subscription, source record should be deleted. Please use “total delete” where possible. Do not set STA=OLSDELETE for records to be deleted for this project. OLSDELETE status will later trigger holding cancelation from WorldCat which we want to avoid.
  8. If a bibliographic record has transaction history (acquisitions or circulation records), then the item record should not be deleted. The item can be moved or suppressed. If the item record is moved, then the Bibliographic record should be manually deleted.
  9. If source has suppressed holdings, items, orders or subscriptions, then suppress the source record with at least one dummy item and holdings record.
  10. Please note when evaluating whether or not a title is a duplicate, sometimes it is necessary to examine the physical item(s). If the items are different editions or have different publishers, publication dates, they are not considered duplicate. A different bibliographic record should to be used. In this case, replace the bibliographic record with an appropriate copy. Do not move items or delete bib records.
  11. The files named xx_duplicate_bibs.xlsx (where xx is your library's OWN code) are listings of Bibliographic records with the same OWN code and the same OCLC number. These may be duplicates, or one of the bibliographic records has an incorrect OCLC number. Please review the file for your library.


Recommended deadline:  May 31, 2020