Re: very impressed by 11g
From: Matthias Hoys <matthias.hoys_at_gmail.com>
Date: Tue, 24 Apr 2012 13:41:56 -0700 (PDT)
Message-ID: <1758185.535.1335300116311.JavaMail.geo-discussion-forums_at_vbmi19>
On Tuesday, April 24, 2012 9:50:44 PM UTC+2, Gerard H. Pille wrote:
> Months ago we upgraded our main database to 11g, and after tuning a number of selects, we were
> running happily along. A couple of weeks ago, we noticed we'd forgotten to change the
> compatible parameter to 11.2 or something, so, yesterday we set that straight.
>
> And brought that system to it's knees.
>
> There was nothing to be done about it, we didn't find any specific queries that were
> responsible, but the system kept hitting 100% cpu.
>
> Finally, we doubled the number of processors, and that solved it. Now and then, the system
> still reaches 50%, but mostly it stays way below it.
>
> That parameter can not be set back, it appears, so we were very lucky we had spare processing
> power, or we would still be struggling.
Date: Tue, 24 Apr 2012 13:41:56 -0700 (PDT)
Message-ID: <1758185.535.1335300116311.JavaMail.geo-discussion-forums_at_vbmi19>
On Tuesday, April 24, 2012 9:50:44 PM UTC+2, Gerard H. Pille wrote:
> Months ago we upgraded our main database to 11g, and after tuning a number of selects, we were
> running happily along. A couple of weeks ago, we noticed we'd forgotten to change the
> compatible parameter to 11.2 or something, so, yesterday we set that straight.
>
> And brought that system to it's knees.
>
> There was nothing to be done about it, we didn't find any specific queries that were
> responsible, but the system kept hitting 100% cpu.
>
> Finally, we doubled the number of processors, and that solved it. Now and then, the system
> still reaches 50%, but mostly it stays way below it.
>
> That parameter can not be set back, it appears, so we were very lucky we had spare processing
> power, or we would still be struggling.
What was the compatible parameter set to originally? 10.2.0.5? Must be that the change activated some new Oracle 11g optimizer features...
Matthias Received on Tue Apr 24 2012 - 15:41:56 CDT