DanBrother的部落格

In Oracle11gR2, the behavior of FLASHBACK_TRANSACTION_QUERY view changes slightly.

select operation,undo_sql from flashback_transaction_query where table_name = 'test_tb';
>>
OPERATION                UNDO_SQL
----------------               ----------------------
UNKNOWN

=> it is because database supplemental logging is not enabled.  (which is by default)

To enable supplemental logging, type:
SQl> ALTER DATABASE ADD SUPPLEMENTAL LOG DATA;

SQl> select supplemental_log_data_min from v$database;
SUPPLEMENTAL_LOG_DATA_MIN
-----------------------------------------------------
YES