RE: Arch log files sizes

From: Yavor Ivanov <Yavor_Ivanov_at_stemo.bg>
Date: Fri, 14 Nov 2008 14:47:56 +0200
Message-ID: <BD17E2E69E17C64A9684C940EB580E0301102BC75047@stemodc1.stemo.local>

                I've seen this (even discussed it on the list)  a month or two ago. It was 10.2.0.4 + RAC on Solaris. The log switches ware very frequent - archive log file sizes were 1-5 MB, while online redo logs were 512 MB each. I could not determine the reason (there was no archive_lag_target set), but after adding some more log groups everything became normal (archive logs as big as 95-100% of the size of online redo logs).
                Two things are sure



-          You archive logs will never be bigger than the online redo logs




-          The total size of archive logs will be always the same (the size of your redo information for given period), no matter the frequency of log stitches. If you have frequent log switches, you simply get more but smaller archivelogs. Of course, there may be a problem with too fast switching, but this does not concern your case.

So you should size your log destination depending the redo generation rate. Regards,
Yavor Ivanov

From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Prabhu, Krishnaswamy Sent: Wednesday, November 12, 2008 8:33 AM To: oracle-l_at_freelists.org
Subject: Arch log files sizes

List,

We are running 10204 instances, recently the arch log destination got filled up 100% and we noticed few arch logs files sizes are varying, the sizes are twice larger than the average file size, archive_lag_target is set to 0. Can anyone please throw more insight on this.

Thanks
Prabhu

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Received on Fri Nov 14 2008 - 06:47:56 CST