Re: Surprising Performance Changes with Oracle 11.2.0.1 (Long Post)
From: Mladen Gogala <gogala.mladen_at_bogus.email.invalid>
Date: Thu, 10 Sep 2009 11:20:48 +0000 (UTC)
Message-ID: <h8aneg$lsi$3_at_solani.org>
Na Thu, 10 Sep 2009 02:20:49 -0700, Gerard H. Pille napisao:
>
> Why do you ask this? Charles clearly states that it was not. Will you
> believe him next time??
Date: Thu, 10 Sep 2009 11:20:48 +0000 (UTC)
Message-ID: <h8aneg$lsi$3_at_solani.org>
Na Thu, 10 Sep 2009 02:20:49 -0700, Gerard H. Pille napisao:
> On 10 sep, 10:26, Mladen Gogala wrote:
>
>
>> Question: was direct I/O enabled here? If not, the blocks may have been >> in the system buffer cache in which case oracle would still report them >> as "physical reads" but blocks would be coming from memory instead. >> >>
>
> Why do you ask this? Charles clearly states that it was not. Will you
> believe him next time??
Because this was the new execution and I lost track of the other conditions. If direct I/O was disabled, Linux buffer cache would have contained the cached blocks and that would explain the difference in performance.
-- http://mgogala.freehostia.comReceived on Thu Sep 10 2009 - 06:20:48 CDT