Database Flashback -- 1

A first post on Database Flashback.

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

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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.