Checking data consistency with internal integrity reports

For application programs, you can record any Db2 return codes that indicate possible data integrity problems, such as inconsistency between index and table information, physical errors on database disk, and so on. All programs must check the SQLCODE or the SQLSTATE for the return code that is issued after an SQL statement is run. Db2 records, on SMF, the occurrence (but not the cause) of physical disk errors and application program abends. The program can retrieve and report this information; the system log (SYSLOG) and the Db2 job output also have this information. However, in some cases, only the program can provide enough detail to identify the exact nature of problem.

You can incorporate these integrity reports into application programs, or you can use them separately as part of an interface. The integrity report records the incident in a history file and writes a message to the operator's console, a database administrator's TSO terminal, or a dedicated printer for certain codes. The recorded information includes the following:

• Date
• Time
• Authorization ID
• Terminal ID or job name
• Application
• Affected view or affected table
• Error code
• Error description

When a Db2 utility reorganizes or reconstructs data in the database, it produces statistics to verify record counts and to report errors. The LOAD and REORG utilities produce data record counts and index counts to verify that no records were lost. In addition to that, keep a history log of any Db2 utility that updates data, particularly REPAIR. Regularly produce and review these reports, which you can obtain through SMF customized reporting or a user-developed program.