Table of Contents
PLP: Special rules
PLP: Special Match Rule exceptions
There are several special exceptions that might be used in PLP during matching to prevent certain types of records from being needlessly directed to No Match or to XC Fail.
All of these exceptions are in addition to any of the various options that are used to configure how record matching functions in PLP 1).
If crosschecks fail … the following special exceptions are checked:
1. If the only crosschecks that fails is X245H, and that is because one record has a GMD and the other does not, and XLGPR is in the match rules for the run and passes, then redirect the records to Match.
The purpose of this exception is to avoid failing large print matches when the arbitrary '[text (large print]) GMD is present in one record but not the other.
2. If the only crosschecks that fails are X245H and XFORM, and X245H fails because one record has a GMD and the other does not, and XFORM fails because one record is coded 'd' and the other is coded '#' (blank), and XLGPR is in the match rules for the run and passes, then redirect the records to Match.
The purpose of this exception is to avoid failing large print matches when the arbitrary '[text (large print]) GMD is present in one record but not the other, and the Form Code has been coded in one record and left out in the other 2).
PLP: Order of precedence when records do not match
When records are compared and do not match, PLP then has to decide what to do with the records, and there often competing options at play during this decision-making process.
Here is the logic, in order of precedence, that the program uses in the case of a no match, to determine which of the myriad options in PLP should be given the upper-hand:
- If the number of DB hits > 'maximum hits', redirect the record to the TooManyHits file.
- If the number of failed crosschecks is > 'max xc fails', redirect the record to the NoMatch file.
- If a “force Nomatch” flag has been set, redirect the record to the NoMatch file3)
- If a crosscheck redirection rule matches, output the record(s) to the Destination set in the matching XCR rule.
- If all crosschecks fail, and exceptions 1-4 do not apply, output the library record and the DB hits to XCFails
- If there are absolutely no hits, the record is output to the NoMatch File (noHitsOnAnyQuery=True)
