The system table <DATABASE_SYSTEM_ADMINISTRATOR>.SYSCHECKSTATISTICSLOG logs all calls of the database procedure SYSCHECKSTATISTICS.
EXECUTIONSTART |
TIMESTAMP |
Start time of SYSCHECKSTATISTICS execution |
EXECUTIONEND |
TIMESTAMP |
End time of SYSCHECKSTATISTICS excution |
CALLER |
CHAR(32) |
Name of the user calling SYSCHECKSTATISTICS |
TABLECOUNT |
FIXED(10) |
Number of tables with an entry in the system table SYSUPDSTATWANTED This number can be smaller than QUALIFIEDTABLECOUNT if there were requests for some of the qualified tables in SYSUPDSTATWANTED already |
RETURNCODE |
FIXED(10) |
Returncode of SYSCHECKSTATISTICS call |
SCHEMAMASK |
CHAR(32) |
Value of SCHEMAMASK parameter used during SYSCHECKSTATISTICS execution |
CHANGETHRESHOLD |
FIXED(3) |
Value of CHANGETHRESHOLD parameter used during SYSCHECKSTATISTICS execution |
QUALIFIEDTABLECOUNT |
FIXED(10) |
Number of tables for which outdated statistics were detected |
The database procedure SYSCHECKSTATISTICS checks the growth of all tables owned by the current database user. If the current size of a table differs more than CHANGETHRESHOLD percent from the table size at last update statistics run, the database procedure SYSCHECKSTATISTICS inserts for this table the relevant information into the system table SYSUPDSTATWANTED. If the database procedure SYSCHECKSTATISTICS is called by the database system administrator the described check is performed for all tables in the database system.
Database Administration, SQL Optimizer Statistics
SQL Reference Manual, UPDATE STATISTICS Statement