Parm Patram » FLASHBACK

Finding changed rows in a table

admin — Mon, 22 Sep 2008 21:32:05 +0000

select ename,sal, versions_xid,versions_startscn,versions_endscn
from scott.emp versions
between scn minvalue and maxvalue
/

SELECT UNDO_SQL
FROM FLASHBACK_TRANSACTION_QUERY
WHERE XID = ‘01000400D3110000′
/

Enabling flashback

admin — Mon, 22 Sep 2008 18:44:47 +0000

shutdown immediate;
startup mount;
alter database archivelog;
alter system set DB_FLASHBACK_RETENTION_TARGET=600; — time is in minutes (10 hours)
alter system set DB_RECOVERY_FILE_DEST_SIZE=2G;
alter system set DB_RECOVERY_FILE_DEST=’/recovery/flashback’;
alter database flashback on;
alter database open;

Recovering using flashback query

admin — Mon, 22 Sep 2008 17:22:03 +0000

select * from &&TABLE as of timestamp to_timestamp(’&&DD-&&MON-&&YY &HOUR:00:00′,’DD-MON-YY HH24: MI: SS’) minus select * from &&TABLE;
– this will allow you to browse backward to find the time when the change occurred
alter table &TABLE enable row movement;
– row movement must be enabled for flashback queries
flashback table &TABLE to timestamp to_timestamp(’&DD-&MON-&YY &HOUR:00:00′,’DD-MON-YY HH24:Mi:SS’);