Re: V$SQLAREA
From: onedbguru <onedbguru_at_yahoo.com>
Date: Wed, 14 Dec 2011 17:46:18 -0800 (PST)
Message-ID: <1d1a3c68-0d72-4991-8f83-0f7f65db4eb5_at_z25g2000vbs.googlegroups.com>
On Dec 14, 3:57 pm, Mladen Gogala <gogala.mla..._at_gmail.com> wrote:
> On Wed, 14 Dec 2011 20:47:02 +0000, Mladen Gogala wrote:
> > In older versions of Oracle, there was a rule saying that V$SQLAREA is
> > evil because queries against it will hit library cache latch once for
> > every row. I was unable to confirm this in 11.2.0.3. The only latch it
> > seems to be hitting is SQL memory manager workarea list latch.
> > Did anyone else notice that? If my findings are right, that would make
> > V$SQLAREA view much more useful for monitoring and querying purposes.
>
> BTW, here is an old discussion from the Oracle-l mentioning V$SQLAREA:
>
> http://www.freelists.org/post/oracle-l/Few-questions-about-VSQLAREA,1
>
> Another text is here:https://netfiles.uiuc.edu/jstrode/www/oraview/V$SQLAREA.html
>
> --http://mgogala.byethost5.com
Date: Wed, 14 Dec 2011 17:46:18 -0800 (PST)
Message-ID: <1d1a3c68-0d72-4991-8f83-0f7f65db4eb5_at_z25g2000vbs.googlegroups.com>
On Dec 14, 3:57 pm, Mladen Gogala <gogala.mla..._at_gmail.com> wrote:
> On Wed, 14 Dec 2011 20:47:02 +0000, Mladen Gogala wrote:
> > In older versions of Oracle, there was a rule saying that V$SQLAREA is
> > evil because queries against it will hit library cache latch once for
> > every row. I was unable to confirm this in 11.2.0.3. The only latch it
> > seems to be hitting is SQL memory manager workarea list latch.
> > Did anyone else notice that? If my findings are right, that would make
> > V$SQLAREA view much more useful for monitoring and querying purposes.
>
> BTW, here is an old discussion from the Oracle-l mentioning V$SQLAREA:
>
> http://www.freelists.org/post/oracle-l/Few-questions-about-VSQLAREA,1
>
> Another text is here:https://netfiles.uiuc.edu/jstrode/www/oraview/V$SQLAREA.html
>
> --http://mgogala.byethost5.com
You have to remember that the whole latch/locking mechanisms changed
with 11.1 and even more in 11.2
Here is a quote from Tanel Poder:
"In Oracle 11g even more library cache operations have been changed to
use KGX mutexes instead of latches."
Expand your search like:
http://lmgtfy.com/?q=oracle+11.2+latch+locking
Received on Wed Dec 14 2011 - 19:46:18 CST