After you perform a backup, or if you experience hardware or operating system failure, you can use the SYSCS_UTIL.SYSCS_CHECK_TABLE system function to verify that the database is still consistent.
It is recommended that you run SYSCS_UTIL.SYSCS_CHECK_TABLE on all the tables in a database offline after you back it up. Do not discard the previous backup until you have verified the consistency of the current one. Otherwise, check consistency only if there are indications that such a check is needed, because a consistency check can take a long time on a large database.
See the Derby Reference Manual for details about this system function.