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Re: How to tune "redo log space request"?

From: Connor McDonald <connor_mcdonald_at_yahoo.com>
Date: Sat, 21 Oct 2000 11:12:23 +0800
Message-ID: <39F10997.7263@yahoo.com>

Michael Bialik wrote:
>
> Hi.
> Try increasing log_buffer to 1048576 ( 1Mb ).
>
> HTH. Michael.
>
> In article <01c03ae1$35d9e960$239e15c2_at_w95luca>,
> "Luca Minudel" <luca.minudel_at_nline.it> wrote:
> > I've got a problem with an Oracle instance.
> > The instance has a "redo log space request" (and a consequent "redo
 log=20
> > space wait time") every time there is a redo log file switch.
> >
> > The redo log files are huge (32MB) and are many (12 redo log groups
 of 1 =
> >
> > file each). They are on 2 different fast disks/controllers/channels.
> > The log_buffer is set to 262144.
> >
> > As I know there should not be "redo log space requests". Isn't it?
> > How can I avoid them?
> > How can I find theyr cause?
> >
> > TIA
> > ___________________________________________________
> > Luca Minudel software designer
> > Italy Conegliano (TV)
> > e-mail luca.minudel_at_nline.it
> > http://www.geocities.com/SiliconValley/Vista/4041
> >
> >
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.

Whilst this lower the redo space statistics, it will probably increase log file sync times as well as making the performance of the LGWR much more sporadic...

You're always going to get some space waits during a log switch - speeding up your log switches may be a better option...

HTH

-- 
===========================================
Connor McDonald
http://www.oracledba.co.uk (mirrored at
http://www.oradba.freeserve.co.uk)

"Early to bed and early to rise, 
 makes a man healthy, wealthy and wise." - some dead guy
Received on Fri Oct 20 2000 - 22:12:23 CDT

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