Re: Redo size vs. archived logs size

From: Mark Bole <makbo_at_pacbell.net>
Date: Tue, 24 May 2005 15:01:30 GMT
Message-ID: <elHke.20713$J12.20453@newssvr14.news.prodigy.com>

Frank van Bortel wrote:

> Dusan Bolek wrote:
> 

>>Hello,
>>
>>during weekend I have been doing stress testing of an archived logs
>>destination on one of our systems here. [...]
>>During a test output analyse phase I realised that the amount of
>>archived logs generated is about ten times bigger than amount of redo
>>size generated taken either from v$mystat or statspack report. Can
>>anyone explain this behaviour? [...]
>>--
>>Dusan Bolek
>>

> 
> Thomas Kyte had some comments about this, and came up with an
> explanation of why the files would be larger, but not by a
> factor 10, just a little over three, iirc.
> It's on asktom.
> 

One possibility would be a tablespace(s) in BACKUP mode (ALTER ... BEGIN BACKUP). But you have probably already eliminated that possibility...

Are you doing commits in your testing? Transaction rollbacks would also take up space in your redo.

-Mark Bole Received on Tue May 24 2005 - 10:01:30 CDT