Re: log_buffer sizing

From: Venkat Krish <venkat.lear_at_gmail.com>
Date: Mon, 15 Aug 2011 15:37:44 -0400
Message-ID: <CAOV8h7sgiQBFe4DFPuXnzf-WMCa_GGzjAFu3ogxx_vJ-jsCaUA_at_mail.gmail.com>

what version? Hopefully you are employing batch commits.

from 11.2 docs<http://download.oracle.com/docs/cd/E11882_01/server.112/e16638/memory.htm#PFGRF94347>

*A reasonable first estimate for such systems is to the default value, which is:*
* *

*MAX(0.5M, (128K * number of cpus))*

• *

*On most systems, sizing the log buffer larger than 1M does not provide any performance benefit. Increasing the log buffer size does not have any negative implications on performance or recoverability. It merely uses extra memory.*

You definitely should look for more convincing evidence (redo related wait events) before you go ahead and start tuning log_buffer size

Regards,
Venkat

On Mon, Aug 15, 2011 at 3:22 PM, K R <kp0773_at_gmail.com> wrote:

> All ,
>
> my online redo logs are 3G . This is a batch intensive datawarehouse
> application. What should i be keeping my log_buffer .
>
> currently it is set at 29425664 and it just seems too low .
>
> thanks
> Kart
>

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Received on Mon Aug 15 2011 - 14:37:44 CDT