RE: Rapid Log Switching

From: Weatherman, John <>
Date: Wed, 20 Feb 2008 16:30:13 -0600
Message-ID: <>

Hmm, this looks intersesting. I have:

star_transformation_enabled string FALSE

transactions                         integer
transactions_per_rollback_segment    integer                          5

so if threads = 98 then reserved space could be could reserve up to 12M, but that doesn't explain why I would see a lot of these switches when only ~2M have been put in the logfile, or why this has changed in the last couple weeks (before AWR went nuts last week, I was getting maybe 3 switches a day...and I know that's bad but I can't get damagement to approve smaller logs)

-----Original Message-----
[] On Behalf Of Jonathan Lewis Sent: Wednesday, February 20, 2008 4:19 PM To:
Subject: Re: Rapid Log Switching


Thanks - Brain didn't catch up with last post there.


I recall Tanel Poder making some comments about "private threads" having space reserved in the log file - do you have a very large value for the 'transactions' parameter: which would require a lot of private threads, which possibly might pre-empt a lot of space in the logs then not use it. (10.2, 64Bit - private threads can take 128Kb each, and threads = ceil(transactions / 10)


Jonathan Lewis

Author: Cost Based Oracle: Fundamentals

The Co-operative Oracle Users' FAQ

  • Original Message ----- From: "Rich Jesse" <> To: <> Sent: Wednesday, February 20, 2008 10:00 PM Subject: Re: Rapid Log Switching

> Hey Jonathon,
> I think he's saying the logs switch when they grow to only 2-to-6
> -- not every 2-to-6 minutes. In other words, "why aren't the logs
> before switching?"
> Rich

>> 20M in 2 to 6 minutes isn't really very much - I assume the
>> puzzle is why have things changed.


Received on Wed Feb 20 2008 - 16:30:13 CST

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