Configuring Flashback Database

Step 1: Check whether the database is in archive log mode.
Step 2: Enable the FRA.
Step 3: Set the init parameter. It specifies how far back you can flashback your database.

SQL> Alter System set DB_FLASHBACK_RETENTION_TARGET=1440 Scope=both;
Step 4: Shutdown and restart the database in Mount mode.

SQL> Shutdown Immediate;
SQL> Startup Mount;

Step 5: Enable the Flashback Database Feature

SQL> Alter Database Flashback ON;

Step 6: Open the database and confirm the status.

SQL> Alter Database open;
SQL> Select flashback_on from v$database;

Step 7: Disable the Flashback Database Feature.

SQL> Shutdown Immediate;
SQL> Startup Mount;
SQL> Alter database flashback off;

Step 8: Disable the Flashback Database for certain Tablespaces.

SQL> Alter Tablespace users FLASHBACK OFF;

Step 9: Enable the Flashback Database for the Tablespace.

SQL> Alter Tablespace users FLASHBACK ON;

Thanks