A first post on Database Flashback.
Enabling Database Flashback in 11.2 non-RAC
So, the above output shows that the database is OPEN but Flashback is not enabled.
Let me enable Flashback now.
Immediately after enabling Flashback, Oracle shows usage of the FRA for Flashback Logs. Note : Although 11.2 allows you to enable Flashback in an OPEN Database, I would suggest doing so when the database is not active.
Enabling Database Flashback in 11.2 non-RAC
SQL*Plus: Release 11.2.0.2.0 Production on Sun Feb 1 23:13:17 2015
Copyright (c) 1982, 2010, Oracle. All rights reserved.
Enter user-name: / as sysdba
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
SYS>select version, status, database_status
2 from v$instance;
VERSION STATUS DATABASE_STATUS
----------------- ------------ -----------------
11.2.0.2.0 OPEN ACTIVE
SYS>select flashback_on, database_role
2 from v$database;
FLASHBACK_ON DATABASE_ROLE
------------------ ----------------
NO PRIMARY
SYS>
SYS>show parameter db_recovery_file
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest string /home/oracle/app/oracle/flash_
recovery_area
db_recovery_file_dest_size big integer 3852M
SYS>
SYS>select * from v$flash_recovery_area_usage;
FILE_TYPE PERCENT_SPACE_USED PERCENT_SPACE_RECLAIMABLE NUMBER_OF_FILES
-------------------- ------------------ ------------------------- ---------------
CONTROL FILE 0 0 0
REDO LOG 0 0 0
ARCHIVED LOG .95 .94 5
BACKUP PIECE 28.88 .12 5
IMAGE COPY 0 0 0
FLASHBACK LOG 0 0 0
FOREIGN ARCHIVED LOG 0 0 0
7 rows selected.
SYS>
So, the above output shows that the database is OPEN but Flashback is not enabled.
Let me enable Flashback now.
SYS>alter database flashback on;
Database altered.
SYS>select flashback_on from v$database;
FLASHBACK_ON
------------------
YES
SYS>select * from v$flash_recovery_area_usage;
FILE_TYPE PERCENT_SPACE_USED PERCENT_SPACE_RECLAIMABLE NUMBER_OF_FILES
-------------------- ------------------ ------------------------- ---------------
CONTROL FILE 0 0 0
REDO LOG 0 0 0
ARCHIVED LOG .95 .94 5
BACKUP PIECE 28.88 .12 5
IMAGE COPY 0 0 0
FLASHBACK LOG .41 0 2
FOREIGN ARCHIVED LOG 0 0 0
7 rows selected.
SYS>
Immediately after enabling Flashback, Oracle shows usage of the FRA for Flashback Logs. Note : Although 11.2 allows you to enable Flashback in an OPEN Database, I would suggest doing so when the database is not active.
