Re: log buffer size (again)

Hello Neil,

The problem is that it increases the average 'log file sync' wait time. That is the wait that users get when they press COMMIT. DBWn also waits on 'log file sync' when checkpointing, and at other times.

The issues are explained fully on my web site (1st URL below) in the tip "Tuning the Log Buffer Size".

Hope this helps,
Regards,
Steve Adams

http://www.ixora.com.au/

http://www.oreilly.com/catalog/orinternals/

http://www.christianity.com.au/

On Fri, 5 Nov 1999 14:18:00 -0000, "Neil" <nc1967_at_hotmail.com> wrote:

>Hi,
>
>I seem to remember this being discussed before - but I am still having
>problems understanding it. The majority of the tuning manuals will suggest
>increasing LOG_BUFFERS until log space requests are (close to) zero.
>However, I think someone (Thomas kyte) gave reasons why this is not a good
>idea.
>As I understand it, the log buffer gets flushed when either it is a third
>full (or as defined by the _log_io_size parameter), or every 3 seconds or on
>a commit.
>What is the problem then with large log buffer if you have sufficient memory
>etc to support it ?
>
>Thanks in advance
>
>Neil
>
>
Received on Fri Nov 05 1999 - 08:23:48 CST