Re: Performance issues when running in archive redo log mode

From: Frank van Bortel <f.van.bortel_at_vnl.nl>
Date: Wed, 03 Nov 1999 13:15:30 -0800
Message-ID: <3820A5F2.CD891B4@vnl.nl>

Birsan wrote:

> One of the consultants that we are working with claims that their tests have
> consistently shown that there is a significant performance hit when ORACLE 7
> (running on UNIX, different flavors, one of them being NCR UNIX), is set to
> operate in archive redo log, as oposed to non archive redo log, mode (the
> performance hit is said to be 30-40%). This confuses me, because I had the
> obvious misconception that the only difference (as long as you do not
> actually issue "alter tablespace begin backup") is that you do not re-use
> the redo logs, but "archive" them, so that they can be used later in the
> recovery process. I certainly did not expect such a big hit, which basically
> stops us from using normal on-line backup procedures, even though
> availability has to be 7x24. For performance reasons as well, the consultant
> recommends not using replication either, which leaves us with the only
> choice of a proprietary application replication scheme, in order to provide
> high availability and database maintenance capabilities (provided by the
> consultant). Can anyone confirm that these claims make sense?
> Thank you for your response!

Eh? You're sure it's a technical consultant, not a sales consultant? What is this performance hit is he talking about? Of course there's a trade off, as the OS needs more processes, memory, disks to write to, etc. Wonder if they got their db structure right... Probably got all of it on one disk. No wonder.

Try it for yourself, that's the nest advice I can give you. For free, too ;-)
--
Met vriendelijke groet/kind regards,

Frank van Bortel
Technical consultant Oracle

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053-4341500 Received on Wed Nov 03 1999 - 15:15:30 CST