With default setting of _use_ism_for_pga set to TRUE - no changes in shared memory segments (pmap -s/pmap -x) were observed during sorting operation. Speaking of mmap/brk calls - no such calls happened _during the sort_ according to truss output. Looks like PGA is not using ISM despite the underscore parameter 8-). Oracle 10.2.0.3, Solaris 10. --romas On Tue, Oct 7, 2008 at 3:08 PM, Yong Huang <yong321@xxxxxxxxx> wrote: > ipcs probably won't show anything interesting. Can you check truss output > when you do a big sort (select count(*) from dba_source order by 1)? Filter > on calls such as brk, mmap (get args of this). Also pmap -x | grep shmid. > See if the mapped size increases when you do big sorting. And, pmap -s <your > shadow process> to see which page size segment increases its size. > > Yong Huang > > > --- On Tue, 10/7/08, Roman Podshivalov <roman.podshivalov@xxxxxxxxx> > wrote: > > > From: Roman Podshivalov <roman.podshivalov@xxxxxxxxx> > > Subject: Re: Hugepages - benefits / drawbacks > > To: yong321@xxxxxxxxx > > Cc: "Christo Kutrovsky" <kutrovsky.oracle@xxxxxxxxx>, > oracle-l@xxxxxxxxxxxxx, krishmanoh@xxxxxxxxx > > Date: Tuesday, October 7, 2008, 1:59 PM > > > > Yep that parameter caught my attention too. I just did a > > quick test and > > started database with this parameter set to true and false. > > No difference in > > ipcs -ma output was found....Could that be related to MTS > > configuration ? > > > > --romas > > > > On Tue, Oct 7, 2008 at 2:55 PM, Yong Huang > > <yong321@xxxxxxxxx> wrote: > > > > > > On Tue, Oct 7, 2008 at 1:26 PM, Yong Huang > > > > <yong321@xxxxxxxxx> wrote: > > > > > Hi Krishna, > > > > > > > > > >> on Solaris PGA uses ISM > > > > > > > > > > Wouldn't that cause PGA to be shared? > > > > > > Tanel Poder's presentation "Memory Management > > and Latching Improvements in > > > Oracle9i and 10g" mentions the parameter > > _use_ism_for_pga. It didn't > > > register in my mind when I read it some time ago. I > > don't have access to > > > Oracle on Solaris right now. Why does Oracle do this? > > It would be > > > interesting to see the effect. > > > > > > Yong Huang > > > >