Monitor redo log (archiving )

hi guys,
not too sure how should i go about monitoring the archiving if i am doing a great amount of DML that will generate lots of archive redo log.
I am concern about the space consume and cpu. Is that any other thing i miss out / or need to look out for.

Mustafa KALAYCI wrote:
don't you sure how much dml will you execute ? you can query V$LOGHISTORY.
also you can check statistics
select sid, name, value
from V$SESSTAT join v$statname using(statistic#)
where name like 'redo size'
and sid = 99999; -- SID hereEdited by: Mustafa KALAYCI on 17.Ağu.2012 01:04erm, updates of about 1M records on a table.

Similar Messages

The file structure online redo log, archived redo log and standby redo log

I have read some Oracle documentation for file structure and settings in Data Guard environment. But I still have some doubts. What is the best file structure or settings in Oracle 10.2.0.4 on UNIX for a data guard environment with 4 primary databases and 4 physical standby databases. Based on Oracle documents, there are 3 redo logs. They are: online redo logs, archived redo logs and standby redo logs. The basic settings are:
1. Online redo logs --- This redo log must be on Primary database and logical standby database. But it is not necessary to be on physical standby database because physical standby is not open. It doesn't generate redo log. However, if don't set up online redo log on physical standby, when primary failover and switch standby as primary. How can standby perform without online redo logs? In my standby databases, online redo logs have been set up.
2. Archived redo logs --- It is obviously that primary database, logical and physical standby database all need to have this log file being set up. Primary use it to archive log files and ship to standby. Standby use it to receive data from archived log and apply to database.
3. Standby redo logs --- In the document, it says A standby redo log is similar to an online redo log, except that a standby redo log is used to store redo data received from another database. A standby redo log is required if you want to implement: The maximum protection and maximum availability levels of data protection and Real-time apply as well as Cascaded destinations. So it seems that this standby redo log only should be set up on standby database, not on primary database. Am my understanding correct? Because I review current redo log settings on my environment, I have found that Standby redo log directory and files have been set up on both primary and standby databases. I would like to get more information and education from experts. What is the best setting or structure on primary and standby database?

FZheng:
Thanks for your input. It is clear that we need 3 type of redo logs on both databases. You answer my question.
But I have another one. In oracle ducument, it says If you have configured a standby redo log on one or more standby databases in the configuration, ensure the size of the current standby redo log file on each standby database exactly matches the size of the current online redo log file on the primary database. It says: At log switch time, if there are no available standby redo log files that match the size of the new current online redo log file on the primary database. The primary database will shut down
My current one data gurard envirnment setting is: On primary DB, online redo log group size is 512M and standby redo log group size is 500M. On the standby DB, online redo log group size is 500M and standby redo log group size is 750M.
This was setup by someone I don't know. Is this setting OK? or I should change Standby Redo Log on standby DB to 512M to exactly meatch with redo log size on primary?
Edited by: 853153 on Jun 22, 2011 9:42 AM

Multiplexing Online redo logs, archive logs, and control files.

Currently I am only multiplexing my control files and online redo logs, My archive logs are only going to the FRA and then being backed up to tape.
We have to replace disks that hold the FRA data. HP says there is a chance we will have to rebuild the FRA.
As my archive logs are going to the FRA now, can I multiplex them to another disk group? And if all of the control files, online redo logs and archive logs are multiplexed to another disk group, when ASM dismounts the FRA disk group due to insufficient number of disks, will the database remain open and on line.
If so then I will just need to rebuild the ASM volumes, and the FRA disk group and bring it to the mount state, correct?
Thanks!

You can save your online redo logs and archive logs anywhere you want by making use of of init params create_online_log_dest and log_archive_dest_n. You will have to create new redo log groups in the new location and drop the ones in the FRA. The archive logs will simply land wherever you designate with log_archive_dest_n parameters. Moving the control files off FRA is a little trickier because you will need to restore your controlfile to a non-FRA destination and then shutdown your instance, edit the control file param to reflect changes and restart.
I think you will be happier if you move everything off the FRA diskgroup before dismounting it, and not expecting the db to automagically recover from the loss of files on the FRA.

How do I manually archive 1 redo log at a time?

The database is configured in archive mode, but automatic archiving is turned off.
For both Oracle 901 and 920 on Windows, when I try to manually archive a single redo log, the database
archives as many logs as it can up to the log just before the current log:
For example:
SQL> select * from v$log order by sequence#;
GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM
1 1 14 104857600 1 NO INACTIVE 424246 19-JAN-05
2 1 15 104857600 1 NO INACTIVE 425087 28-MAR-05
3 1 16 104857600 1 NO INACTIVE 425088 28-MAR-05
4 1 17 512000 1 NO INACTIVE 425092 28-MAR-05
5 1 18 512000 1 NO INACTIVE 425100 28-MAR-05
6 1 19 512000 1 NO CURRENT 425102 28-MAR-05
6 rows selected.
SQL> alter system archive log next;
System altered.
SQL> select * from v$log order by sequence#;
GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM
1 1 14 104857600 1 YES INACTIVE 424246 19-JAN-05
2 1 15 104857600 1 YES INACTIVE 425087 28-MAR-05
3 1 16 104857600 1 YES INACTIVE 425088 28-MAR-05
4 1 17 512000 1 YES INACTIVE 425092 28-MAR-05
5 1 18 512000 1 NO INACTIVE 425100 28-MAR-05
6 1 19 512000 1 NO CURRENT 425102 28-MAR-05
See - instead of only 1 log being archive, 4 of them were. Oracle behaves the same way if I use the "sequence" option:
SQL> select * from v$log order by sequence#;
GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM
1 1 14 104857600 1 NO INACTIVE 424246 19-JAN-05
2 1 15 104857600 1 NO INACTIVE 425087 28-MAR-05
3 1 16 104857600 1 NO INACTIVE 425088 28-MAR-05
4 1 17 512000 1 NO INACTIVE 425092 28-MAR-05
5 1 18 512000 1 NO INACTIVE 425100 28-MAR-05
6 1 19 512000 1 NO CURRENT 425102 28-MAR-05
6 rows selected.
SQL> alter system archive log next;
System altered.
SQL> select * from v$log order by sequence#;
GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM
1 1 14 104857600 1 YES INACTIVE 424246 19-JAN-05
2 1 15 104857600 1 YES INACTIVE 425087 28-MAR-05
3 1 16 104857600 1 YES INACTIVE 425088 28-MAR-05
4 1 17 512000 1 YES INACTIVE 425092 28-MAR-05
5 1 18 512000 1 NO INACTIVE 425100 28-MAR-05
6 1 19 512000 1 NO CURRENT 425102 28-MAR-05
Is there some default system configuration property telling Oracle to archive as many logs as it can?
Thanks,
DGR

Thanks Yoann (and Syed Jaffar Jaffar Hussain too),
but I don't have a problem finding the group to archive or executing the alter system archive log command.
My problem is that Oracle doesn't work as I expect it.
This comes from the Oracle 9.2 online doc:
http://download-west.oracle.com/docs/cd/B10501_01/server.920/a96540/statements_23a.htm#2053642
"Specify SEQUENCE to manually archive the online redo log file group identified by the log sequence number integer in the specified thread."
This implies that Oracle will only archive the log group identified by the log sequence number I specify in the alter system archive log sequence statement. However, Oracle is archiving almost all of the log groups (see my first post for an example).
This appears to be a bug, unless there is some other system parameter that is configured (by default) to allow Oracle to archive as many log groups as possible.
As to the reason why - it is an application requirement. The Oracle db must be in archive mode, automatic archiving must be disabled and the application must control online redo log archiving.
DGR

Offline redo log history list.....??

Im looking for a way how to determine offline redo log frequency for past days eventualy longer period of time and also the list of redo logs archived with creation time stamp. As far as Ive been able to check probably it could be mantaned by V$LOG_HISTORY or V$ARCHIVED_LOG.
Any suggestion for best way ?
DB: Oracle 10
Tks

Hi,
Your can use following statement to check the log switching frequency. This statement i found somewhere from internet but don't remember the source, apology for that
set lines 200
select to_date(to_char(first_time,'DD-MM-YYYY'),'DD-MM-YYYY') day,
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'00',1,0)),'999') "00",
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'01',1,0)),'999') "01",
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'02',1,0)),'999') "02",
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'03',1,0)),'999') "03",
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'04',1,0)),'999') "04",
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'05',1,0)),'999') "05",
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'06',1,0)),'999') "06",
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'07',1,0)),'999') "07",
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'08',1,0)),'999') "08",
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'09',1,0)),'999') "09",
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'10',1,0)),'999') "10",
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'11',1,0)),'999') "11",
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'12',1,0)),'999') "12",
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'13',1,0)),'999') "13",
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'14',1,0)),'999') "14",
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'15',1,0)),'999') "15",
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'16',1,0)),'999') "16",
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'17',1,0)),'999') "17",
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'18',1,0)),'999') "18",
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'19',1,0)),'999') "19",
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'20',1,0)),'999') "20",
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'21',1,0)),'999') "21",
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'22',1,0)),'999') "22",
to_char(sum(decode(substr(to_char(first_time,'HH24'),1,2),'23',1,0)),'999') "23",
sum(1) "TOTAL_IN_DAY"
from v$log_history
group by to_date(to_char(first_time,'DD-MM-YYYY'),'DD-MM-YYYY')
order by day
/Salman

Urgent: Huge diff in total redo log size and archive log size

Dear DBAs
I have a concern regarding size of redo log and archive log generated.
Is the equation below is correct?
total size of redo generated by all sessions = total size of archive log files generated
I am experiencing a situation where when I look at the total size of redo generated by all the sessions and the size of archive logs generated, there is huge difference.
My total all session redo log size is 780MB where my archive log directory size has consumed 23GB.
Before i start measuring i cleared up archive directory and started to monitor from a specific time.
Environment: Oracle 9i Release 2
How I tracked the sizing information is below
logon as SYS user and run the following statements
DROP TABLE REDOSTAT CASCADE CONSTRAINTS;
CREATE TABLE REDOSTAT
AUDSID NUMBER,
SID NUMBER,
SERIAL# NUMBER,
SESSION_ID CHAR(27 BYTE),
STATUS VARCHAR2(8 BYTE),
DB_USERNAME VARCHAR2(30 BYTE),
SCHEMANAME VARCHAR2(30 BYTE),
OSUSER VARCHAR2(30 BYTE),
PROCESS VARCHAR2(12 BYTE),
MACHINE VARCHAR2(64 BYTE),
TERMINAL VARCHAR2(16 BYTE),
PROGRAM VARCHAR2(64 BYTE),
DBCONN_TYPE VARCHAR2(10 BYTE),
LOGON_TIME DATE,
LOGOUT_TIME DATE,
REDO_SIZE NUMBER
TABLESPACE SYSTEM
NOLOGGING
NOCOMPRESS
NOCACHE
NOPARALLEL
MONITORING;
GRANT SELECT ON REDOSTAT TO PUBLIC;
CREATE OR REPLACE TRIGGER TR_SESS_LOGOFF
BEFORE LOGOFF
ON DATABASE
DECLARE
PRAGMA AUTONOMOUS_TRANSACTION;
BEGIN
INSERT INTO SYS.REDOSTAT
(AUDSID, SID, SERIAL#, SESSION_ID, STATUS, DB_USERNAME, SCHEMANAME, OSUSER, PROCESS, MACHINE, TERMINAL, PROGRAM, DBCONN_TYPE, LOGON_TIME, LOGOUT_TIME, REDO_SIZE)
SELECT A.AUDSID, A.SID, A.SERIAL#, SYS_CONTEXT ('USERENV', 'SESSIONID'), A.STATUS, USERNAME DB_USERNAME, SCHEMANAME, OSUSER, PROCESS, MACHINE, TERMINAL, PROGRAM, TYPE DBCONN_TYPE,
LOGON_TIME, SYSDATE LOGOUT_TIME, B.VALUE REDO_SIZE
FROM V$SESSION A, V$MYSTAT B, V$STATNAME C
WHERE
A.SID = B.SID
AND
B.STATISTIC# = C.STATISTIC#
AND
C.NAME = 'redo size'
AND
A.AUDSID = sys_context ('USERENV', 'SESSIONID');
COMMIT;
END TR_SESS_LOGOFF;
Now, total sum of REDO_SIZE (B.VALUE) this is far less than archive log size. This at time when no other user is logged in except myself.
Is there anything wrong with query for collecting redo information or there are some hidden process which doesnt provide redo information on session basis.
I have seen the similar implementation as above at many sites.
Kindly provide a mechanism where I can trace which user is generated how much redo (or archive log) on a session basis. I want to track which all user/process are causing high redo to generate.
If I didnt find a solution I would raise a SR with Oracle.
Thanks
[V]

You can query v$sess_io, column block_changes to find out which session generating how much redo.
The following query gives you the session redo statistics:
select a.sid,b.name,sum(a.value) from v$sesstat a,v$statname b
where a.statistic# = b.statistic#
and b.name like '%redo%'
and a.value > 0
group by a.sid,b.name
If you want, you can only look for redo size for all the current sessions.
Jaffar

Select from .. as of - using archived redo logs - 10g

Hi,
I was under the impression I could issue a "Select from .. as of" statement back in time if I have the archived redo logs.
I've been searching for a while and cant find an answer.
My undo_management=AUTO, database is 10.2.0.1, the retention is the default of 900 seconds as I've never changed it.
I want to query a table as of 24 hours ago so I have all the archived redo logs from the last 48 hours in the correct directory
When is issue the following query
select * from supplier_codes AS OF TIMESTAMP
TO_TIMESTAMP('2009-08-11 10:01:00', 'YYYY-MM-DD HH24:MI:SS')
I get a snapshot to old ORA-01555 error. I guess that is because my retention is only 900 seconds but I thought the database should query the archive redo logs or have I got that totally wrong?!
My undo tablespace is set to AUTOEXTEND ON and MAXSIZE UNLIMITED so there should be no space issues
Any help would be greatly appreciated!
Thanks
Robert

If you want to go back 24 hours, you need to undo the changes...
See e.g. the app dev guide - fundamentals, chapter on Flashback features: [doc search|http://www.oracle.com/pls/db102/ranked?word=flashback&remark=federated_search].

Hoping for a quick response : EXP and Archived REDO log files

I apologize in advance if this question has been asked and answered 100 times. I admit I didn't search, I don't have time. I'm leaving on vacation tomorrow, and I need to know if I'm correct about something to do with backup / restore.
we have 10g R2 running a single instance on a single server. The application vendor has "embedded" oracle with their application. The vendor's backup is a batch file using EXP - thus:
exp system/xpwdxx@db full=y file=D:\Orant\admin\db\EXP\db_full.dmp log=D:\Orant\admin\db\EXP\db_full.txt direct=y compress=y
This command is executed nightly at midnight. The files are then backed up by our nightly backup to offsite storage media.
Te database is running in autoarchive mode. The problem is, the archived redo files filled the drive they were being stored on, and it is the drive the database is on. I used OS commands to move 136G of archived redo logs onto other storage media to free the drive.
My question: Since the EXP runs at midnight, when there is likely NO activity, do I need to run in AutoArchive Mode? From what I have read, you cannot even apply archived redo log files to this type of backup strategy (IMP) Is that true? We are ok losing changes since our last EXP. I have read a lot of stuff about restoring consistent vs. inconsistent, and just need to know: If my disk fails, and I have to start with a clean install of Oracle and nothing else, can I IMP this EXP and get back up and running as of the last EXP? Or do I need the autoarchived redo log files back to July 2009 (136G of them).
Hoping for a quick response
Best Regards, and thanks in advance
Bruce Davis

Bruce Davis wrote:
Amardeep Sidhu
Thank you for your quick reply. I am reading in the other responses that since I am using EXP without consistent=y, I might not even have a backup. The application vendor said that with this dmp file they can restore us to the most recent backup. I don't really care for this strategy as it is untested. I asked them to verify that they could restore us and they said they tested the dmp file and it was OK.
Thank you for taking the time to reply.
Best Regards
BruceThe dump file is probably ok in the sense it is not corrupted and can be used in an imp operation. That doesn't mean the data in it is transactionally consistent. And to use it at all, you have to have a database up and running. If the database is physically corrupted, you'll have to rebuild a new database from scratch before you can even think about using your dmp file.
Vendors never understand databases. I once had a vendor tell me that Oracle's performance would be intolerable if there were more than 5 concurrent connections. Well, maybe in HIS product ..... Discussions terminated quickly after he made that statement.

Problem while archiving the redo Log

Hi all,
I m having few issues in my server...
I get the following error in the alert log of oracle..
There are many errors
1) No space left on device
2) ARC0: I/O error 19502 archiving log 1 to
'/oracle/admin/SNM/arch/arch_1_393_668727286.arc'
ARCH: Archival stopped, error occurred. Will continue retrying
3) ORA-16014: log 1 sequence# 393 not archive*d, no available destinations*
Also please find the v$log file query
SQL> select * from v$log;
GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS
FIRST_CHANGE# FIRST_TIM
1 1 405 1073741824 1 NO CURRENT
60275455 20-OCT-09
2 1 403 1073741824 1 NO INACTIVE
59987366 19-OCT-09
3 1 404 1073741824 1 NO INACTIVE
60125083 20-OCT-09
Also the diskspace is almost 97%.
Can anyone let me know whether archival of redo log files is causing the issue here?
If so if i stop the archival of logs ,will it solve the problem?
Can anyone help me on this?
Mon Oct 19 09:54:39 2009
Errors in file /oracle/admin/SNM/bdump/snm_arc0_23831.trc:
ORA-19502: write error on file
"/oracle/admin/SNM/arch/arch_1_393_668727286.arc", blockno
577537 (blocksize=512)
ORA-27063: number of bytes read/written is incorrect
SVR4 Error: 28: No space left on device
Additional information: -1
Additional information: 1048576
ORA-19502: write error on file
"/oracle/admin/SNM/arch/arch_1_393_668727286.arc", blockno
559105 (blocksize=512)
Mon Oct 19 09:54:39 2009
Errors in file /oracle/admin/SNM/bdump/snm_arc0_23831.trc:
ORA-19502: write error on file
"/oracle/admin/SNM/arch/arch_1_393_668727286.arc", blockno
577537 (blocksize=512)
ORA-27063: number of bytes read/written is incorrect
SVR4 Error: 28: No space left on device
Additional information: -1
Additional information: 1048576
ORA-19502: write error on file
*"/oracle/admin/SNM/arch/arch_1_393_668727286.arc", blockno*
*559105 (blocksize=512)*
ARC0: I/O error 19502 archiving log 1 to
'/oracle/admin/SNM/arch/arch_1_393_668727286.arc'
ARCH: Archival stopped, error occurred. Will continue retrying
Mon Oct 19 09:54:40 2009
ORACLE Instance SNM - Archival Error
Mon Oct 19 09:54:40 2009
ORA-16038: log 1 sequence# 393 cannot be archived
ORA-19502: write error on file "", blockno (blocksize=)
ORA-00312: online log 1 thread 1: '/oracle/oradata/SNM/redo01.log'
Mon Oct 19 09:54:40 2009
Errors in file /oracle/admin/SNM/bdump/snm_arc0_23831.trc:
ORA-16038: log 1 sequence# 393 cannot be archived
ORA-19502: write error on file "", blockno (blocksize=)
ORA-00312: online log 1 thread 1: '/oracle/oradata/SNM/redo01.log'
Mon Oct 19 09:54:40 2009
ARCH: Archival stopped, error occurred. Will continue retrying
Mon Oct 19 09:54:40 2009
ORACLE Instance SNM - Archival Error
Mon Oct 19 09:54:40 2009
ORA-16014: log 1 sequence# 393 not archived, no available destinations
ORA-00312: online log 1 thread 1: '/oracle/oradata/SNM/redo01.log'
Mon Oct 19 09:54:40 2009
Errors in file /oracle/admin/SNM/bdump/snm_arc1_23833.trc:
ORA-16014: log 1 sequence# 393 not archive*d, no available destinations*
ORA-00312: online log 1 thread 1: '/oracle/oradata/SNM/redo01.log'
Mon Oct 19 10:00:16 2009
ARC0: Encountered disk I/O error 19502
Mon Oct 19 10:00:16 2009
ARC0: Closing local archive destination LOG_ARCHIVE_DEST_1:
'/oracle/admin/SNM/arch/arch_1_393_668727286.arc' (error
19502)
(SNM)

yes it is the production server.
Also the arch folder contains 2 GB file - arc file....
Does disable of archival will solve the issue?
I am try to clear the space or move to some other location..But the thing is my application files is of 3 to 4 GB.remaining thing is of dbf files.
6564 drwxr-x--- 2 oracle oinstall 512 Oct 21 2008 .
6563 drwxr-x--- 3 oracle oinstall 512 Oct 21 2008 ..
6568 -rw-r----- 1 oracle oinstall 7061504 Sep 30 11:58 control01.ctl
6569 -rw-r----- 1 oracle oinstall 7061504 Sep 30 11:58 control02.ctl
6570 -rw-r----- 1 oracle oinstall 7061504 Sep 30 11:58 control03.ctl
9283 -rw-r----- 1 oracle oinstall 5128192 Sep 30 10:21 mfxpima.dbf
6600 -rw-r----- 1 oracle oinstall 17179877376 Sep 30 11:50 muse0.dbf
6572 -rw-r----- 1 oracle oinstall 1073742336 Sep 30 08:10 redo01.log
6573 -rw-r----- 1 oracle oinstall 1073742336 Sep 30 10:16 redo02.log
6574 -rw-r----- 1 oracle oinstall 1073742336 Sep 30 11:58 redo03.log
6578 -rw-r----- 1 oracle oinstall 19293806592 Sep 30 11:58 sysaux01.dbf
6576 -rw-r----- 1 oracle oinstall 1698701312 Sep 30 11:56 system01.dbf
6579 -rw-r----- 1 oracle oinstall 2147491840 Sep 30 11:04 temp01.dbf
6577 -rw-r----- 1 oracle oinstall 4084211712 Sep 30 11:58 undotbs01.dbf
6580 -rw-r----- 1 oracle oinstall 5251072 Sep 30 10:21 users01.dbf
What as to be done....in this case....
Help me out...
I have no other option ....
SRinivasan

Where RFS exactly write redo data ? ( archived redo log or standby redo log ) ?

Good Morning to all ;
I am getting bit confused from oracle official link . REF_LINK : Log Apply Services
Redo data transmitted from the primary database is received by the RFS on the standby system ,
where the RFS process writes the redo data to either archived redo log files or standby redo log files.
In standby site , does rfs write redo data in any one file or both ?
Thanks in advance ..

Hi GTS,
GTS (DBA) wrote:
Primary & standby log file size should be same - this is okay.
1) what are trying to disclose about largest & smallest here ? - You are confusing.
Read: http://docs.oracle.com/cd/E11882_01/server.112/e25608/log_transport.htm#SBYDB4752
"Each standby redo log file must be at least as large as the largest redo log file in the redo log of the redo source database. For administrative ease, Oracle recommends that all redo log files in the redo log at the redo source database and the standby redo log at a redo transport destination be of the same size."
GTS (DBA) wrote:
2) what abt group members ? should be same as primary or need to add some members additionally. ?
Data Guard best practice for performance, is to create one member per each group in standby DB. on standby DB, one member per group is reasonable enough. why? to avoid write penalty; writing to more than one log files at the standby DB.
SCENARIO 1: if in your source primary DB you have 2 log member per group, in standby DB you can have 1 member per group, additionally create an extra group.
primary
standby
Member per group
2
1
Number of log group
4
5
SCENARIO 2: you can also have this scenario 2 but i will not encourage it
primary
standby
Member per group
2
2
Number of log group
4
5
GTS (DBA) wrote:
All standby redo logs of the correct size have not yet been archived.
- at this situation , can we force on standby site ? any possibilities ?
you can not force it , just size your standby redo files correctly and make sure you don not have network failure that will cause redo gap.
hope there is clarity now
Tobi

Recover Database is taking more time for first archived redo log file

Hai,
Environment Used :
Hardware : IBM p570 machine with P6 processor Lpar of .5 CPU and 2.5 GB Ram
OS : AIX 5.3 ML 07
Cluster: HACMP 5.4.1.2
Oracle Version: 9.2.0.4 RAC
SAN : DS8100 from IBM
I have used flash copy option to copy the database from production to test machine. Then tried to recover the database to an consistent state using the command "recover automatic database until cancel". System is taking long time and after viewing the alert log it was found that, for the first time, if it is reading all the datafiles and it is taking 3 seconds for each datafile. Since i have more than 500 datafiles, it is nearly taking 25 mins for applying the first archived redo log file. All other log files are applied immeidately without any delay. Any suggession to improve the speed will be highly appreciated.
Regards
Sridhar

After chaning the LPAR settings with 2 CPU and 5GB RAM, the problem solved.

Db restore non archive mode lost redo log file..restore from controlfile tr

i have a db 11g I had taken non archive backup but failed to take redo log files backup...
so while i restored the db ... after formatting the machine ..the oracle instance wont start.
I create a controlfile trace but when i run it i get errors.
since i dont have the older log files.. how do i get around with this issue
Thanks
Following is the sample of control file trace ..Note i cannot create the redo log file
since db wont be mounted at most it shall be in nonmount mode
and below is my created controlfile ....
CREATE CONTROLFILE REUSE DATABASE "XE" NORESETLOGS NOARCHIVELOG
MAXLOGFILES 16
MAXLOGMEMBERS 3
MAXDATAFILES 100
MAXINSTANCES 8
MAXLOGHISTORY 292
LOGFILE
GROUP 1
'C:\ORACLEXE\APP\ORACLE\FLASH_RECOVERY_AREA\XE\ONLINELOG\O1_MF_1_80L7C259_.LOG'
SIZE 50M BLOCKSIZE 512,
GROUP 2
'C:\ORACLEXE\APP\ORACLE\FLASH_RECOVERY_AREA\XE\ONLINELOG\O1_MF_2_80L7C375_.LOG'
SIZE 50M BLOCKSIZE 512
-- STANDBY LOGFILE
DATAFILE
'C:\ORACLEXE\APP\ORACLE\ORADATA\XE\SYSTEM.DBF',
'C:\ORACLEXE\APP\ORACLE\ORADATA\XE\UNDOTBS1.DBF',
'C:\ORACLEXE\APP\ORACLE\ORADATA\XE\SYSAUX.DBF',
'C:\ORACLEXE\APP\ORACLE\ORADATA\XE\USERS.DBF'
CHARACTER SET AL32UTF8
I dont have these 2 files ..what do i do to get around this situation
'C:\ORACLEXE\APP\ORACLE\FLASH_RECOVERY_AREA\XE\ONLINELOG\O1_MF_1_80L7C259_.LOG'
SIZE 50M BLOCKSIZE 512,
GROUP 2
'C:\ORACLEXE\APP\ORACLE\FLASH_RECOVERY_AREA\XE\ONLINELOG\O1_MF_2_80L7C375_.LOG'
SIZE 50M BLOCKSIZE 512
-- STANDBY LOGFILE
DATAFILE
Edited by: zycoz100 on Feb 27, 2013 10:57 PM

If you have a cold backup (database shutdown properly) without the redo logs, change this :
CREATE CONTROLFILE REUSE DATABASE "XE" NORESETLOGS NOARCHIVELOGto
CREATE CONTROLFILE REUSE DATABASE "XE" RESETLOGS NOARCHIVELOGYou have to change the NORESETLOGS to RESETLOGS for Oracle to recreate the online redo logs.
Hemant K Chitale

Delete old and unused Archived Redo Log Files

Hello forum!
My db was in ARCHIVELOG mode and It created 9GB of archived redo log files.
Now I put the db in NOARCHIVELOG mode, can I delete all the ARLF? am I sure that the DB never need those files in the future?
If yes, how can I delete them? I will use 'del' operative system command?
In addition, I found this command:
SQL>alter database open resetlogs;
is it useful for my purpose?
thank you!

You are safe to remove those archivelog files if you altered your database to no archive log mode. Just remove them from OS level
Please bear in mind that database in no archivelog mode will lost data in the event of disaster.
SQL>alter database open resetlogs;Doesn't help in your situation, it's use to bring up database after incomplete recovery.

Manual archiving of redo log files....

Hi ,
If the database is running in NOARCHIVELOG mode , is it possible to archive the redo log files manually.... and how..????
Note: I use Oracle 10g v.2
Many thanks,
Simon

Having issued the command , i noticed that the USE_DB_RECOVERY_FILE_DEST is the destination of LOG_ARCHIVE_DEST_10:
SQL> select dest_id,dest_name,status,destination from V$ARCHIVE_DEST;
   DEST_ID DEST_NAME                                                                        STATUS    DESTINATION
         1 LOG_ARCHIVE_DEST_1                                                               VALID     C:\oracle\product\10.2.0\flash_recovery_area\EPESY\ARCHIVELOG\
         2 LOG_ARCHIVE_DEST_2                                                               INACTIVE
         3 LOG_ARCHIVE_DEST_3                                                               INACTIVE
         4 LOG_ARCHIVE_DEST_4                                                               INACTIVE
         5 LOG_ARCHIVE_DEST_5                                                               INACTIVE
         6 LOG_ARCHIVE_DEST_6                                                               INACTIVE
         7 LOG_ARCHIVE_DEST_7                                                               INACTIVE
         8 LOG_ARCHIVE_DEST_8                                                               INACTIVE
         9 LOG_ARCHIVE_DEST_9                                                               INACTIVE
        10 LOG_ARCHIVE_DEST_10                                                              VALID     USE_DB_RECOVERY_FILE_DESTBut... i have set the LOG_ARCHIVE_DEST parameter not ...._10.
How the system will point to the directory i've set in my previous alter system command...- when i use the archive log list???
Many thanks,
Simon

Archived redo log size more less than online redo logs

Hi,
My database size around 27 GB and redo logs sizes are 50M. But archive log size 11M or 13M, and logs are switching every 5-10min. Why?
Regards
Azer Imamaliyev

Azer_OCA11g wrote:
1) Almost all archive logs sizes are 11 or 13M.. But sometimes 30, 37M.
2)
select to_char(completion_time, 'dd.mm.yyyy HH24:MI:SS')
from v$archived_log
order by completion_time desc;
10.02.2012 11:00:26
10.02.2012 10:50:23
10.02.2012 10:40:05
10.02.2012 10:29:34
10.02.2012 10:28:26
10.02.2012 10:18:07
10.02.2012 10:05:04
10.02.2012 09:55:03
10.02.2012 09:40:54
10.02.2012 09:28:06
10.02.2012 09:13:44
10.02.2012 09:00:17
10.02.2012 08:45:04
10.02.2012 08:25:04
10.02.2012 08:07:12
10.02.2012 07:50:06
10.02.2012 07:25:05
10.02.2012 07:04:50
10.02.2012 06:45:04
10.02.2012 06:20:04
10.02.2012 06:00:12
3) There arent any serious change at DB level.. almost these messages show in alert log since creating DB..Two simple thoughts:
1) Are you running with archive log compression - add the "compressed" column to the query above to see if the archived log files are compressed
2) The difference may simply be a reflection of the number and sizes of the public and private redo threads you have enabled - when anticipating a log file switch Oracle leaves enough space to cater for threads that need to be flushed into the log file, and then doesn't necessarily have to use it.
Here's a query (if you can run as SYS) to show you your allocation of public and private threads
select
     PTR_KCRF_PVT_STRAND           ,
     FIRST_BUF_KCRFA               ,
     LAST_BUF_KCRFA                ,
     TOTAL_BUFS_KCRFA              ,
     STRAND_SIZE_KCRFA             ,
     indx
from
     x$kcrfstrand
;Regards
Jonathan Lewis
http://jonathanlewis.wordpress.com
Author: <b><em>Oracle Core</em></b>

Monitor redo log (archiving )

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