Re: Tuning 'log file sync'

From: Mark Bole <makbo_at_pacbell.net>
Date: Mon, 05 Sep 2005 01:45:22 GMT
Message-ID: <SqNSe.352$JN5.328@newssvr13.news.prodigy.com>

Mladen Gogala wrote:

> On Fri, 02 Sep 2005 09:43:57 +0200, Sybrand Bakker wrote:
>
>

>>I frequently observed log file sync problems when increasing
>>log_buffer.
>>This is logical as the log buffer is locked by LGWR when LGWR flushes
>>the buffer to the online redo log file.
>>IMO, you should decrease log_buffer to anything below 1M and you are
>>shooting yourself in your foot now.

>
>

[...]
> In version 8, transactions would wait for the LGWR to flush the entire
> buffer, but that is no longer the case. Transactions now wait until
> only their data has been written to disk. So, large buffer is no longer an
> obstacle. [...]

I don't follow your logic here. What if the transaction's data is at the end of a large buffer?

-Mark Bole Received on Sun Sep 04 2005 - 20:45:22 CDT