Oracle outstanding alerts

Since Oracle 10g you can configure alerts for database events like tablespace size (and a lot more), and by default the instance issues alerts about tablespace size, therefore you can check all the alerts and also database block corruption with this sentences:

SQL> column REASON           format A35
SQL> column SUGGESTED_ACTION format A35
SQL> column TIME_SUGGESTED   format A35

SQL> select REASON, SUGGESTED_ACTION, TIME_SUGGESTED from dba_alert_history union
select REASON, SUGGESTED_ACTION, TIME_SUGGESTED from dba_outstanding_alerts
order by TIME_SUGGESTED;

REASON                              SUGGESTED_ACTION                    TIME_SUGGESTED
----------------------------------- ----------------------------------- -----------------------------------
Tablespace [UNDO] is [76 percent] f Add space to the tablespace         07-MAY-11 01.47.40.716220 AM -05:00
           ull

Tablespace [UNDO] is [73 percent] f Add space to the tablespace         07-MAY-11 03.07.46.785262 AM -05:00
           ull

SQL> SELECT * FROM V$DATABASE_BLOCK_CORRUPTION;

no rows selected

Needless to say, if you have data in the V$DATABASE_BLOCK_CORRUPTION view you might have serious problems with your database.