PLP/MCU Overview

PLP/MCU is a software package designed to reduce the number of duplicate records in union catalogs, and additionally, provide tools for effectively dealing with duplicates and 'near-matches' in these catalogs.

PLP (Pre-Load Processor) reads a file of records that is to be loaded into the union catalog. For each record in the file, PLP sends one or more queries to the database in an attempt to determine whether that record is already present.

MCU (MARC Compare Utility) is a companion utility for viewing matching groups of records that PLP determined to be 'Possible' matches, and quickly making decisions about what to do with these records.

Each PLP query, in general, has three possible results:

  • Match–the record is already present in the database
  • NoMatch–the record is not present in the database
  • Possible Match–One or more DB records matched the incoming record, but failed crosschecks

With these results from PLP, the user may then:

  • Load the records in the 'Match' file to the system using an Add-item-only or Overlay profile
  • Load the 'NoMatch' record to the system using a Add-as-new-record profile
  • Review the possible matches in MCU and decide how the records that failed crosschecks will be loaded on a case-by-case basis

Using sophisticated and precise rule-driven parameters, PLP is designed to prevent both duplicates and bad matches from being added to the database, while MCU is designed to make the process of human review as efficient as possible.


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PLP Pre-processing

The purpose of PLP-processing is to ensure that there are no problems in the file–particularly in the SysId and Holdings code fields–before database matching/merging begins.

For each record in the incoming file, the following actions are performed:

  • Run OSMOSIS1) Global Fixes on the file
  • Dedupe and map (or create) the holdings codes used by the library
  • Normalize and map the library's System Id

PLP-Preprocessing is always the first task performed whenever PLP is run.

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Also included in PLP/MCU is a module, which, for lack of a better name, we call 'Self-PLP'. Instead of searching a file against the database, Self-PLP compares all the records in a file against one another.

When matching records are found, Self-Plp performs the same basic actions as PLP:

  • Records that match and pass crosschecks can be merged together
  • Records that match but fail crosschecks can be queued for review in the MCU
  • Records that do not match can be output to a separate 'NoMatch' file, etc.

Whereas PLP requires SQL access to an Oracle database, Self-PLP requires only a file of MARC records.

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More Details

1) OSMOSIS is the TMQ product used by libraries to identify Adds and Deletes in their database for batchloading to the union catalog
start.txt · Last modified: 2013/10/22 02:57 (external edit)
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