Re: log_buffer sizing

From: ORA600 <panandrao_at_gmail.com>
Date: 27 May 2006 03:54:34 -0700
Message-ID: <1148727274.382555.226580@u72g2000cwu.googlegroups.com>

It all depends on your redo rate. Jaffar has given you an example of one of the most common issues with large sized log buffers.

50M is as big waste of memory. If you have large batch DML as opposed to short 'OLTP' type of transactions, then you could use a 2MB or more. We sometimes use a 5MB just to ensure that we don't have to wait for log buffer space...and our application needs it.

a good starting point is 640K or 1MB, most generic applications can make do with this size.

look at the statistic "Redo size" at the top of your Statspack report. That will give you an idea of how much redo you are generating every second and per transaction.

Load Profile

~~~~~~~~~~~~       Per Second       Per Transaction
                  ---------------       ---------------
 Redo size:          1,013,633.11             15,327.16

that should help you size your log buffer.

cheers
anand Received on Sat May 27 2006 - 05:54:34 CDT