Oracle – when was last time my index was rebuilt?
Taking a look at the LAST_DDL_TIME you can find the last time.
select OBJECT_NAME, timestamp, LAST_DDL_TIME from dba_objects where OBJECT_NAME=’IX_CARDBLOCKS’
SQL> alter index rebuild ix_cardblocks;
Run the first command again and you should see a change in time on LAST_DDL_TIME to current.