in Oracle

Database Flashback — 4

Continuing my series on Oracle Database Flashback.

[oracle@localhost Hemant]$ sqlplus '/ as sysdba'

SQL*Plus: Release 11.2.0.2.0 Production on Tue Feb 17 22:30:53 2015

Copyright (c) 1982, 2010, Oracle. All rights reserved.


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 sysdate from dual;

SYSDATE
---------
17-FEB-15

SYS>show parameter db_flashback_retention_target

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_flashback_retention_target integer 1440
SYS>select * from v$flashback_database_log;

OLDEST_FLASHBACK_SCN OLDEST_FL RETENTION_TARGET FLASHBACK_SIZE ESTIMATED_FLASHBACK_SIZE
-------------------- --------- ---------------- -------------- ------------------------
14573520 15-FEB-15 1440 190971904 0

SYS>

After my last post on 15/16-Feb (midnight), I had generated some transactions. The Flashback Size has grown from 24.576MB to 190.972MB.

Question : Does Database Flashback always apply to the whole database ? Can we exclude a selected tablespace ?

SYS>create tablespace TEST_NOFB;

Tablespace created.

SYS>alter tablespace TEST_NOFB flashback OFF;

Tablespace altered.

SYS>

So, it is possible to set FLASHBACK OFF for a tablespace ! What are the implications ? Oracle does NOT save Flashback information for this tablespace. If I need to Flashback the Database, this tablespace or all the datafiles in this tablespace must be taken OFFLINE or DROPped.

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