If this property is set to true, the thread that updates index cardinality statistics during query compilation will write messages to the Derby system log (derby.log) every time it performs a task. The log entries should help you to diagnose problems with the automatic updating of index statistics.
The derby.storage.indexStats.trace property can be used to provide more detailed information and to specify where the trace output should appear.
To disable the automatic updating of index statistics, set the database property derby.storage.indexStats.auto to false.
For more information about index statistics, see "Working with cardinality statistics" in Tuning Derby.
-- system-wide property derby.storage.indexStats.log=true
-- database-level property CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY( 'derby.storage.indexStats.log', 'true')
Static. For system-wide properties, you must reboot Derby for the change to take effect. For database-wide properties, you must reboot the database for the change to take effect.