Re: performance problems after increasing redolog size

From: Howard J. Rogers <howardjr2000_at_yahoo.com.au>
Date: Fri, 07 Mar 2003 06:17:09 +1100
Message-Id: <pan.2003.03.06.19.17.08.755996@yahoo.com.au>

On Thu, 06 Mar 2003 13:09:44 +0000, Niall Litchfield wrote:

> "Howard J. Rogers" <howardjr2000_at_yahoo.com.au> wrote in message
> news:pan.2003.03.05.19.36.59.512043_at_yahoo.com.au...

>> >> It can't be. Adding redo log groups will have absolute zero performance
>> >> impact, and something else is amiss.
>> >
>> > Could it be that ARCH is now failing to keep up? This should show up in

> the

>> > alert log.
>>
>> If his logs had increased to 100GB, I'd buy this! But if ARCH can't cope
>> with a 10MB log, something is seriously amiss...

>
> As indeed, now the information has trickled out it is.
>
> 1cpu machine, 1gb ram, 4 databases, all oracle software and databases on a
> single raid5 set. System is generating significant redo (at least
> 30mb/minute at peak times if I read the alert.log correctly). At which point
> archiving is switched on. You could probably design a worse performing
> system, bjut ikt would be fairly difficult to do.
>

;-)

Agree completely!

Still, it's impressive. I can't recall ever being able to demonstrate so effectively that turning on archiveing can cause performance problems. 2 hours down to 24... that's quite some change!!

Regards
HJR
>
> --
> Niall Litchfield
> Oracle DBA
> Audit Commission UK
Received on Thu Mar 06 2003 - 13:17:09 CST