Re: Measuring the impact of Redo Log change

From: Eagle Fan <>
Date: Wed, 10 Sep 2008 10:45:54 +0800
Message-ID: <>

I think the average wait time of "log file sync" is also a good statistics to look at.

On Tue, Sep 9, 2008 at 12:32 PM, Deepak Sharma <
> wrote:

> We recently (today) moved the redo logs from RAID5 to RAID1+0.
> The obvious reason of doing this is to make things better in terms of
> performance, as RAID1+0 is better suited for read/writes. Someone pls
> correct me if that's not true.
> What are different ways to measure the impact of this change?
> The platform is AIX, DB is and DB size is 55TB, and 2TB redo is
> generated each day. There are plans underway to reduce the redo generation
> using direct path etc. (so let's not get diverted by that).
> We can try measuring the wait event stats using AWR, session stats etc.,
> but what exactly to look for? 'log file switch completion', 'log file
> sync', are some things that come to mind - what else?
> Thanks,
> Deepak

Eagle Fan


Received on Tue Sep 09 2008 - 21:45:54 CDT

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