9. PROCESSING › 9.3 Data Integrity Considerations

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9.3 Data Integrity Considerations


The section of the DB2 Analyzer that reads the DB2
accounting and statistical records from the SMF file
incorporates a number of provisions for validating the
integrity of the SMF data:

o  Record length checks
o  Missing data checks
o  Duplicate data checks
o  Improper data combination checks

Messages are written to the SAS log if the DB2 Analyzer
detects any of these conditions.

In addition, the DB2 Analyzer detects the restart of DB2.
This is required for the proper calculation of data in the
DB2 System Activity and Data Base Activity files.  The
procedure involves checking the sequence number of each DB2
SMF record.

It should be remembered that DB2 SMF data is not checkpointed
and is not preserved over a DB2 restart.  If a restart
occurs, some data may be lost.