Surprising Performance Changes with Oracle 11.2.0.1 (Long Post)

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.



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