RE: .: How to track logfile switch

From: M Rafiq <>
Date: Fri, 3 Oct 2008 12:23:39 -0400
Message-ID: <BAY107-W47B33419311F8EF47F4CEFA13C0@phx.gbl>

It suggests to increase sizes of your redo log files and/or add some more groups and observe how it goes.  


From: Yavor_Ivanov_at_stemo.bgTo:; oracle-l_at_freelists.orgDate: Fri, 3 Oct 2008 18:35:53 +0300Subject: .: How to track logfile switch

 The value of ARCHIVE_LAG_TARGET is 0  

Unfortunately the message "Thread X cannot allocate new log, sequence XXXX" is sometimes followed by "Checkpoint not complete". So I cannot ignore it easily. Yesterday there was a short but noticeable database hang at the same time when this happened.  

Yavor Ivanov  

: Bobak, Mark []: 03 2008 . 17:11: Yavor Ivanov; oracle-l: RE: How to track logfile switch

Whats the value of ARCHIVE_LAG_TARGET?  

--Mark J. BobakSenior Database Administrator, System & Product TechnologiesProQuest789 E. Eisenhower, Parkway, P.O. Box 1346Ann Arbor MI 48106-1346+1.734.997.4059 or +1.800.521.0600 x 4059mark.bobak_at_proquest.comwww.proquest.comwww.csa.comProQuest...Start here.

From: [] On Behalf Of Yavor IvanovSent: Friday, October 03, 2008 9:59 AMTo: oracle-lSubject: FW: How to track logfile switch  

                Forgot to say the version. It is

Yavor Ivanov
Oracle Certified Master  

From: [] On Behalf Of Yavor IvanovSent: Friday, October 03, 2008 4:50 PMTo: oracle-lSubject: How to track logfile switch  

                Hello, gurus
                I have a strange problem. I am auditing a  system with 2 node Oracle RAC on Solaris. I found in the alert log the following ugly message:
Thread  cannot allocate new log, sequence 
                It happens may times. I started to dig inside the problem. I found that the system is setup with 2 redo logs per thread, each of them is 512 MB. I do not think this is wise, but this is not the problem. I noticed in v$archived_log that the size of archived logs (BLOCKS * BLOCK_SIZE) is somewhere between 1 and 3 MB (!), far less than 512 MB. Log switch is happening every 1-5 minutes.
                Am I missing something? It is Friday afternoon here, and everything seems to me so strange that I started to think I am missing something very major. I am using the following query to get the size of the files generated for some period:
select l.THREAD#, l.SEQUENCE#, l.FIRST_TIME, l.NEXT_TIME, l.BLOCKS * l.BLOCK_SIZE / 1024 / 1024   from v$archived_log l
 where round(next_time, 'HH24') = to_date('03.10.2008 10:00', 'DD.MM.YYYY HH24:MI')  
                Also I was hoping to catch who is making all this log switches using AFTER DDL ON DATABASE trigger, but the trigger does not fire for alter system switch logfile. Maybe this statement is not DDL. Can somebody see what am I missing?

Yavor Ivanov  

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-- Received on Fri Oct 03 2008 - 11:23:39 CDT

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