oracle flashback 2

Flashback  database

     After oracle 10g, oracle can rollback to an prior time by flashback database when there is a error operation or careless operation. In order to come true this target, oracle add another log file group "flashback logs" which records the oracle database's prior operations.

     It can recover database to a specific time by the snapshot which is equal or less prior time of the specified time.

     It can recover database to a specific time by archive log file.

     In order to use the flashback database tool, you need configure the parameter that: db_recover_file_dest  db_recover_file_dest_size 

For oracle 10g, you need to engine the flashback database tool in the mount mode as the sql:

     alter database flashback on

     or 

     alter tablespace ts_name flashback on

To close the flashback database, just change on to off.

Syntac:

          flashback database to time to_date();

          flashback database to time to timestamp();

          flashback database to scn xxx;

          flashback database to sequence xxx thread 1;

          flashback database to timestamp(sysdate - 1/24);