Enabling Flashback
Hi,
when I enable flashback using the following -
define the FRA ( db_recovery_file_dest_size and db_recovery_file_dest )
ensure the DB is in archive log mode
set the flashback_rentention_target
alter database flashback on;
what exactly am I enabling ?
Is it the underlying requirements for all the flashback tools ( eg flashback query, table, database ) ?
What about flashback table drop ?
I have a database that does not have the FRA defined and has not enabled flashback, yet I am able to issue
flashback table <name> to before drop;
why can I do this if flashback is not enabled ?
I think you are enabling the flashback logs, which allow you to issue the 'flashback database' command. Flashback Drop uses the recycle bin. The other ones use UNDO data.
Edited by: marcusrangel on Feb 10, 2012 2:37 PM
Similar Messages
-
A new question on how to Enable Flashback Database on the standby database?
Best Practice document said:
Enable Flashback Database on the standby database to minimize downtime for logical corruptions.
I would like to know where to find document or anybody already had experience for this topic?
Also I would like to know what is the best practice for backup/recovery of the Physcial standby database?
Thanks in advance.Hello;
Just an opinion but I like the book "Oracle Data Guard 11g Handbook" as both the document and the answers to the second question.
Chapter 12 covers the A to Z of RMAN with Data Guard.
This book sold me on Flashback since Flashback allows a former Primary database to be reinstated after a failover operation with being restored ( provided sufficient flashback logs are available)
My own experience is I tried a failover test without it and trash my test Primary.
I did a simple failover test a few weeks ago, here are my notes.
http://www.visi.com/~mseberg/Data_Guard_Failover_Test_using_SQL.pdf
Best Regards
mseberg -
Query on administration tasks required for enabling flashback feature
Hi All,
I would like to enable FLASHBACK on 4 tables in a schema.
I know that the RETENTION GUARANTEE clause needs to be set on the UNDO TABLESPACE. But as flashback is required only on few tables, setting RETENTION GUARANTEE will cause a lot of pressure on the tablespace in terms of space.
Can anyone suggest a solution for this?
Thanks in advance,
AnnieAudit information will appear in the 'Output' panel in the Test View and the Query Plan View after executing if the application is Audit enabled and the audit 'Severity (threshhold) Level' is set such that audit events are generated. (i.e. if you have the Severity Level set to Failure, then audit events will not be generated for events that specify 'Info')
There is no 'Audit Console' for DSP. -
Cannot enable flashback database??
I am using 10gR2 10.2.0.1
Under EM Home: it shows under " High Availability ":
Last Backup Apr 14, 2007 8:03:33 PM
Usable Flash Recovery Area (%) 92.35
Flashback Logging Disabled
When I get to the "recovery settings", I have make sure I have turned on Archivelogmode, however, the "enable flashback database" section was missing.
What's wrong about my database settings?
I have tried to explicitly do the standard code and have got the following errors:
SQL> SHUTDOWN IMMEDIATE;
SQL>STARTUP MOUNT EXCLUSIVE;
//report: obsolete/deprecated parameter specified"
SQL> ALTER SYSTEM SET DB_FLASHBACK_RETENTION_TARGET=2800 SCOPE=BOTH;
//no error
SQL>ALTER DATABASE FLASHBACK ON;
//error: ORA-00439: feature not enabled, flashback database
Message was edited by:
gilbert.laiDear Satish,
The results of v$version:
BANNER
Oracle Database 10g Release 10.2.0.1.0 - Production
PL/SQL Release 10.2.0.1.0 - Production
CORE 10.2.0.1.0 Production
TNS for 32-bit Windows: Version 10.2.0.1.0 - Production
NLSRTL Version 10.2.0.1.0 - Production
The results of v$option:
PARAMETER VALUE
Partitioning FALSE
Objects TRUE
Real Application Clusters FALSE
Advanced replication FALSE
Bit-mapped indexes FALSE
Connection multiplexing TRUE
Connection pooling TRUE
Database queuing TRUE
Incremental backup and recovery TRUE
Instead-of triggers TRUE
Parallel backup and recovery FALSE
Parallel execution FALSE
Parallel load TRUE
Point-in-time tablespace recovery FALSE
Fine-grained access control FALSE
Proxy authentication/authorization TRUE
Change Data Capture FALSE
Plan Stability TRUE
Online Index Build FALSE
Coalesce Index FALSE
Managed Standby FALSE
Materialized view rewrite FALSE
Materialized view warehouse refresh FALSE
Database resource manager FALSE
Spatial FALSE
Visual Information Retrieval FALSE
Export transportable tablespaces FALSE
Transparent Application Failover TRUE
Fast-Start Fault Recovery FALSE
Sample Scan TRUE
Duplexed backups FALSE
Java TRUE
OLAP Window Functions TRUE
Block Media Recovery FALSE
Fine-grained Auditing FALSE
Application Role FALSE
Enterprise User Security FALSE
Oracle Data Guard FALSE
Oracle Label Security FALSE
OLAP FALSE
Table compression FALSE
Join index FALSE
Trial Recovery FALSE
Data Mining FALSE
Online Redefinition FALSE
Streams Capture FALSE
File Mapping FALSE
Block Change Tracking FALSE
Flashback Table FALSE
Flashback Database FALSE
Data Mining Scoring Engine FALSE
Transparent Data Encryption FALSE
Backup Encryption FALSE
Unused Block Compression FALSE
The strange thing is that whenever I issued
startup force;
or
startup mount exclusive;
with SYSDBA privileges, it reports: "obsolete / deprecate parameters specified ", is there sth wrong with the init parameters? -
Why Database should be in mount stage for enable Flashback
Oracle 11.1.0.6.0
Windows
Why database should be in mount stage for enabling flashback feature but we can disable this feature even in Open mode?
Kindly share your inputs .
Thanks,
Alok>
As per doc this is prerequisites that database should be in mount mode to enable flashback but we can disable flashback even in open mode.
I would like to know the concept behind this.
>
Only Oracle knows why and why, for 11g, you can now have the database open. Any 'guesses' would only be guesses.
You can get some possible clues from the DBA guide section for 10g 'Starting Up and Shutting Down' the database.
http://docs.oracle.com/cd/B19306_01/server.102/b14231/start.htm
Traditionally MOUNT mode (database closed) is used for administrative activities by the DBA that need to be done either when there is no user activity that might conflict with them.
>
Starting Up an Instance
•Start the instance and mount the database, but leave it closed. This state allows for certain DBA activities, but does not allow general access to the database.
>
Or this from the same doc a little later on
>
Starting an Instance and Mounting a Database
You can start an instance and mount a database without opening it, allowing you to perform specific maintenance operations. For example, the database must be mounted but not open during the following tasks:
•Enabling and disabling redo log archiving options. For more information, please refer to Chapter 7, "Managing Archived Redo Logs".
•Performing full database recovery. For more information, please refer to Oracle Database Backup and Recovery Basics
The following command starts an instance and mounts the database, but leaves the database closed:
STARTUP MOUNT
>
Perhaps part of the flashback enable process required exclusive access to ALL tablespaces or datafiles; meaning you can't have users modifying them.
Perhaps the enable process for 10g needed to perform simultaneous updates to all datafile headers, the controlfiles and undo or cache or data dictionary entries; meaning you can't have users getting in the way.
Dont' know. -
Is there any step by step procedure to enable flashback in oracle9i?
Friends,
I am in a situation to enable the flashback option in oracle9iR2.
I didnt find anywhere....
i saw this....
http://download-uk.oracle.com/docs/cd/B10501_01/appdev.920/a96590/adg08sql.htm#10851
even though its not step by step.
can anybody point me the document which is having a step by step setup?
or anybody is having a self document to enable flashback in oracle9iR2.
thanks
sathyguyhere is the result....
SQL> SELECT * FROM EMP;
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
7369 SMITH CLERK 7902 17-DEC-1980 800 20
7499 ALLEN SALESMAN 7698 20-FEB-1981 1600 300 30
7521 WARD SALESMAN 7698 22-FEB-1981 1250 500 30
7566 JONES MANAGER 7839 02-APR-1981 2975 20
7654 MARTIN SALESMAN 7698 28-SEP-1981 1250 1400 30
7698 BLAKE MANAGER 7839 01-MAY-1981 2850 30
7782 CLARK MANAGER 7839 09-JUN-1981 2450 10
7788 SCOTT ANALYST 7566 19-APR-0087 3000 20
7839 KING PRESIDENT 17-NOV-1981 5000 10
7844 TURNER SALESMAN 7698 08-SEP-1981 1500 0 30
7876 ADAMS CLERK 7788 23-MAY-0087 1100 20
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
7900 JAMES CLERK 7698 03-DEC-1981 950 30
7902 FORD ANALYST 7566 03-DEC-1981 3000 20
7934 MILLER CLERK 7782 23-JAN-1982 1300 10
14 rows selected.
SQL> DELETE FROM EMP;
14 rows deleted.
SQL> COMMIT;
Commit complete.
SQL> SELECT * FROM EMP
2 AS OF TIMESTAMP to_timestamp('08-APR-2007','DD-MON-YYYY');
SELECT * FROM EMP
ERROR at line 1:
ORA-01466: unable to read data - table definition has changed[\pre]
i tried to enable flashback before the above statement like this....
SQL> EXEC DBMS_FLASHBACK.ENABLE_AT_TIME('08-APR-2007','DD-MON-YYYY')
BEGIN DBMS_FLASHBACK.ENABLE_AT_TIME('08-APR-2007','DD-MON-YYYY'); END;
ERROR at line 1:
ORA-06550: line 1, column 7:
PLS-00306: wrong number or types of arguments in call to 'ENABLE_AT_TIME'
ORA-06550: line 1, column 7:
PL/SQL: Statement ignored
so.....how can i enable this?
Thanks -
Could anyone explain me what is archive mode, and how to do it?
I tried to enable the Flashback Database in oracle 10g, or maybe you all can guide me how to enable flashback oracle.user10316225 wrote:
Let oracle docs be your friend,
http://download.oracle.com/docs/cd/E11882_01/server.112/e10595/archredo003.htm#i1106237
guess this link is for 11g. still there shouldnt be any change in the procedure i guess.No that's deliberately given for 11g as OP didn't mention any db version in the first line. For 2nd line, because 10g was mentioned that's why I gave 10g specific doc. You are correct though that the procedure is exactly same for both 10/11g to put a database in archivelog and in general as well that what is Archive log mode.
Aman.... -
Enabling flashback database adds unsupported spfile parameter
After enabling the flashback database I saw a new policy violation upon restart.
awrflush_threshold_metrics was set to true and added to the spfile. When I look that up, I get various dire warnings about using it.
If it's not supported, why does Oracle do this by default upon enabling the flashback database? And, is it necessary for the flashback database to work, or can I remove it?What's your OS and DB versions?
Since 10g R2 this parameter Enables/Disables Flushing AWR Workload Metrics.
You should not set this hidden parameter unless directed by Oracle Support. All parameters that start with underscore (_) are considered internal and unsupported, which means that only Oracle is authorized to set them.
~ Madrid -
Trying to enable flashback database on 11g Linux platform database
Hello,
SQL> ALTER DATABASE FLASHBACK ON;
ALTER DATABASE FLASHBACK ON
ERROR at line 1:
ORA-38759: Database must be mounted by only one instance and not open
Can any one help understand why I am getting this error while I have only one instance open?
Thanks
AlainAs Hemant asked, what's the status of the db, is it mounted or open? Issue,
select status from V$instance This would show the status to you. If it's open , you must bring it to the mount stage with a clean shutdown and then retry.
HTH
Aman.... -
What are the required configuration tasks to enable flashback feature?
Hi,
I want to use the flashback feature on a table. Can anyone tell me what are the configuration changes that needs to be done in order to use this feature?
Thanks in advance,
Anniehttp://www.oracle.com/technology/deploy/availability/htdocs/Flashback_Overview.htm
if you mean ...
Flashback Table
When a human or application error occurs, you want to be able to restore the state of one or more tables to a point in time before the problem occurred.
You have to set UNDO_RETENTION initialization parameter.
http://download-west.oracle.com/docs/cd/B19306_01/server.102/b14220/backrec.htm#i1015145
if you mean..
Flashback Drop
In Oracle Database 10g. When a user drops a table, Oracle automatically places it into the Recycle Bin.
By the way it can not use with table on SYSTEM tablespace. -
Best practice on using Flashback and Logical Standby
Hello,
I'm testing a fail-back scenario where I first need to activate a logical standby, then do some dummy transactions before I flashback this db and resme the redo apply. Here is what the steps look like:
1) Ensure logical standby is in-sync with primary
2) Enable flashback on standby
3) Create a flashback guaranteed restore point
4) Defer log shipping from primary
5) Activate the logical standby so it’s fully open to read-write
6) Dummy activities against the standby (which is now fully open)
7) Flashback the database to the guaranteed checkpoint
8) Resume log shipping on primary
9) Resume redo apply on secondary
In the end, i can see the log shipping is happening but the logical standby does not apply any of these..and there is no error in the alert log on Standby side. But the following query could explains why the standby is idle:
SELECT TYPE, HIGH_SCN, STATUS FROM V$LOGSTDBY;
TYPE HIGH_SCN STATUS
COORDINATOR ORA-16240: Waiting for log file (thread# 2, sequence# 0)
ORA-16240: Waiting for log file (thread# string, sequence# string)
Cause: Process is idle waiting for additional log file to be available.
Action: No action necessary. This informational statement is provided to record the event for diagnostic purposes.
I dont understand why it's looking for sequence #0 after the flashback.
Thanks for the help.Hello;
I hesitate to answer your question because you are not doing a good job of keeping the forum clean :
Total Questions: 13 (13 unresolved)
Please consider closing some of you old answered questions and rewarding those who helped you.
No action necessary.
Do you really have a thread 2? ( Redo thread number )
Quick check
select applied_scn,latest_scn from v$logstdby_progress;Use the DBA_LOGSTDBY_LOG View if you don't have a thread 2 then the sequence# is meaningless.
COLUMN DICT_BEGIN FORMAT A10;
SELECT FILE_NAME, SEQUENCE#, FIRST_CHANGE#, NEXT_CHANGE#,
TIMESTAMP, DICT_BEGIN, DICT_END, THREAD# AS THR# FROM DBA_LOGSTDBY_LOG
ORDER BY SEQUENCE#;Logical Standby questions are difficult, not a lot of them out there I'm thinking.
Check
http://docs.oracle.com/cd/E14072_01/server.112/e10700/manage_ls.htm
"Waiting On Gap State" ( However I still believe you don't have a 2nd thread# )
OR
http://psilt.wordpress.com/2009/04/29/simple-logical-standby/
Best Regards
mseberg
Edited by: mseberg on Apr 26, 2012 5:13 PM -
Flashback in dataguard environment
Hi,
We have dataguard environment with Sun OS & Oracle 10g, 11g. Now we want to enable flashback for the primary database as well as standby database (physical standby). NO RMAN. I did manage to configure the flashback for the primary database but confusion is:
-- Do I need to configure flashback at standby or recreate standby after enabling flashback at primary site?
-- Suppose if I use flashback database to restore point and open database with resetlogs, what would be the situation at standby site? Will it be in sync with primary or after resetlogs I need to make new standby database??
-- Is there any space requirement ratio for flashback recovery partition?
Thanks,
Amit.If you only enabled flashback on your Primary, your Standby is not affected. If you did actually a flashback database on your Primary, you need to address that on the Standby. See an example here:
http://uhesse.wordpress.com/oracle-database-ha-architecture/2010/08/06/using-flashback-in-a-data-guard-environment/
Kind regards
Uwe Hesse
http://uhesse.wordpress.com -
Deleting the flashback recovery area and the files (Oracle 10g on Solaris 8
Hi,
We have a dev. db which is small about 3 gb in all (crd files). for this I had enabled flashback and also put it in archivelog mode. then the db_recovery_file_dest_size grew to 3 gb. since space is an issue, I turned off the flashback feature. (by the command: ALTER DATABASE FLASHBACK OFF;)
Tomorrow I will also make it into noarchivelog mode. My question is: it is having lots of archived logs (may be 3 gb or more) in the flashback recovey area. What is the correct syntax to delete them? There is a warning in alert log which says that use RMAN delete command but I am not aware of exact syntax.
Thanks
NiravYou can use variations of delete. (As you say there are many files, incude noprompt)
Once the database goes into noarchivelog mode, the archived redo logs are essentially worthless. They would be useful/necessary if you wanted to restore the database to a point in time prior to going noarchive, but if you don't need that, the two ways you are looking at deleting (depending how you go about it) are at the OS level and within the database (what Oracle knows or remembers about the archived redo logs and where they were sent to via the arch process). The RMAN approach is cleaner, assuming you were using that.
http://download.oracle.com/docs/cd/B19306_01/backup.102/b14192/maint009.htm#sthref776
Delete unnecessary files from the flash recovery area using the RMAN DELETE command. (Note that if you use host operating system commands to delete files, then the database will not be aware of the resulting free space. You can run the RMAN CROSSCHECK command to have RMAN re-check the contents of the flash recovery area and identify expired files, and then use the DELETE EXPIRED command to remove missing files from the RMAN repository.) -
Reset to previous RESTORE POINT only possible with FLASHBACK ?
Ok, I can create a Restore Point (in v10g) by a command like:
CREATE RESTORE POINT foobar;
Actually I expected a symmetric command which reverts the whole database back
with a command like
RESET to RESTORE POINT foobar;
However I did not found such a (or similar) command.
Instead the only way I found was by a FLASHBACK command:
FLASHBACK DATABASE TO RESTORE POINT foobar;
Is this correct? Is there no other command for reverting back to a previous RESTORE POINT?
PeterHI
Well there is no such command "RESET to RESTORE POINT foobar".....its... "Flashback database to restore point"
now question is that why we use flashback database to restore point? for example we want to run some application on our database but we are not sure that it might create some unwanted changes in our database ...so we mount our database and enable flashback then we create restore point let say "create restore point beforeupgrade"....and then we run our application now if we find some unwanted changes in our database we will flashback database to created restore point.
here is the link to understand more......
http://arjudba.blogspot.com/2008/04/performing-flashback-database.html.. -
Standby database failover flashback restart as standby gap 1-100
Hi,
I have setup a physical standby database for a 3 node RAC primary database and configured the database to run in MAXIMUM AVAILABILITY mode. Both the primary and standby databases use ASM for managing the IO. I have enabled FLASHBACK ON on both the databases.
I did failover to standby database with primary db SHUTDOWN for doing some testing. After testing is done, I flashbacked the (standby, currently primary)database to the point when it became primary and start it as standby again and the old primary as primary.
Following are the steps:
Failover steps
.Shutdown the primary database
To finisish the recovery at standby
SQL>alter database recover managed standby database finish;
To start as primary
SQL>alter database commit to switchover to primary;
do some DML on the new primary
SQL>flashback database to scn <standby_became_primary_scn>;
SQL>alter database create standby controlfile as '/backup/standby.ctl';
Changed the spfile to point control_files to '/backup/standby.ctl';
Restarted the standby db in mount mode and
created the required stanbdy logs on it.
Then issued
SQL>alter database recover managed standby database using current logfile disconnect;
I have the following message in v$dataguard_status at standby db;
Fetching gap sequence in thread 1 branch(resetlogs_id) 653234404, gap seq 1-100
DBID 2651011616 branch 653234404
GAP - thread 1 sequence 1-100
FAL[client]: Failed to request gap sequence
FAL[client]: All defined FAL servers have been attempted.
The same error is found in alert log file also.
The status of the varioud managed standby db are as follows.
SQL> select process, status from v$managed_standby;
PROCESS STATUS
ARCH CLOSING
ARCH CLOSING
ARCH CLOSING
MRP0 WAIT_FOR_GAP
RFS IDLE
RFS IDLE
RFS IDLE
RFS IDLE
RFS IDLE
RFS IDLE
RFS IDLE
PROCESS STATUS
RFS IDLE
RFS IDLE
RFS IDLE
RFS IDLE
15 rows selected.
SQL>
Could you please help me how to resolve the above error.
Thanks,
SreekanthSreekanth,
I think your steps are right on for your requirement, except instead of
alter database create standby controlfile as '/backup/standby.ctl';
you can do this:
ALTER DATABASE CONVERT TO PHYSICAL STANDBY;
(although perhaps it achieves the same thing internally but you don't need to repoint to new controlfile).
So far as the GAP - thread 1 sequence 1-100
Let me guess, your current sequences are probably well ahead of this reported gap?
If so, this is a bogus gap in a sense that your standby has long ago applied them, but for some reason standby controlfile gets a little confused and starts asking for them again.
I have had this issue and opened multiple TAR's with Oracle since 10.2.0.1, got a few patches and advises to upgrade, but still occasionally get it now in 10.2.0.3
I strongly believe this is related to combination of RAC (i.e. multiple threads of redo) and dataguard.
It is also pretty hard to reproduce (I have not figured out how to reproduce this reliably, if you have, let me know), so I can understand why Oracle has so far been unable to fix this.
Anyway, the workaround is to re-create standby controlfile with a copy generated on primary, and move it in place of the existing (and confused) controlfiles on standby.
Maybe you are looking for
-
when I attempt to access iTunes, I receive a message reading, "this copy of iTunes is corrupted or installed improperly, please reinstall iTunes," How do I do this and not lose my existing music library?
-
How to change the GUI title of a standard SAP screen
Hi Gurus Could u pls help me on this I want to chnage the GUI title of a standard SAP screen without modifying the standard code. Thanks in advance Regards Swatantra
-
Converting ASCII characters to integer values
I'm trying to convert characters to ints in order to see if they are within the ASCII encoding set. Having trouble finding a method to do this.
-
I have installed visual studio express 2013 update 4 for windows 8 desktop but not getting console application template under visual c#.Please help me.............In am eager to work on it but stucked. A little help would be great.
-
Do I need put VALIDATE DATABASE in RMAN? I have crosscheck backup
Does the Crosscheck backup tell if a database has corruption? do I need run command validate database?