RE: PLSQL CPU consumption
- From: "Bobak, Mark" <Mark.Bobak@xxxxxxxxxxxxxxx>
- To: <panandrao@xxxxxxxxx>, <ade.turner@xxxxxxxxx>
- Date: Tue, 26 Sep 2006 09:05:46 -0400
Um, how is cursor_space_for_time "known to be CPU bound"? It will
certainly cause higher memory usage, but how does it affect CPU
consumption?
--
Mark J. Bobak
Senior Oracle Architect
ProQuest Information & Learning
"A human being should be able to change a diaper, plan an invasion,
butcher a hog, conn a ship, design a building, write a sonnet, balance
accounts, build a wall, set a bone, comfort the dying, take orders, give
orders, cooperate, act alone, solve equations, analyze a new problem,
pitch manure, program a computer, cook a tasty meal, fight efficiently,
die gallantly. Specialization is for insects." --Robert A. Heinlein
________________________________
From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Anand Rao
Sent: Tuesday, September 26, 2006 12:49 AM
To: ade.turner@xxxxxxxxx
Cc: oracle-l@xxxxxxxxxxxxx
Subject: Re: PLSQL CPU consumption
Hi,
i would try disabling cursor_space_for_time. it is known to be CPU
bound. not very sure how much of that is affecting you. your wait event
suggests libary cache issues. i am no good with ref cursors, so i can't
really comment on that.
could be that there are large no. of copies of the same statement or
that your packages / sql are getting invalidated from inside another
proc. needs more diagnosis for sure.
just try,
cursor_space_for_time=false
and bounce your instance.
your next step is to drill down into V$SQL, V$SQLAREA and all those
packages. do you use a lot of SQL from inside those packages?
cheers
anand
On 26/09/06, Adrian <ade.turner@xxxxxxxxx> wrote:
Hi David,
Sorry, I'm not onsite (UK based) so cant give you exact info,
but pretty much
Latch Free(librarycache) 50%
CPU Time, 45%
sequential read(much lower) 5%
The latch frees only appear under CPU starvation. Under normal
load its 90% to CPU Time.
Tkprof output does not seem to show the considerable cpu time
attributed by v$sqlarea to the package call.
Cheers
Adrian
________________________________
From: David Sharples [mailto:davidsharples@xxxxxxxxx]
Sent: 25 September 2006 20:33
To: ade.turner@xxxxxxxxx
Cc: oracle-l@xxxxxxxxxxxxx
Subject: Re: PLSQL CPU consumption
what are you biggest wait / timed events
--
All I need to make a comedy is a park, a policeman and a pretty girl -
Charlie Chaplin
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