On Fri, Apr 22, 2016 at 5:21 PM raghu vineel <raghuvin...@gmail.com> wrote:
> > Hi, > > I have a 4 core CPU for postgres and I have submitted 6 queries parallely > in 6 different sessions. But I am seeing only 1 query per CPU and the > remainig queries are queued. I am not sure why is it happening. Do you have > any special scheduler for postgres? I can see that CPU has been shared with > other non postgres processes but postgres processes are not sharing any CPU > within a core. The following is the process states. > > > *lms 2868 2209 98 07:20 ? 00:02:30 postgres: lms controller > [local] SELECTlms 2869 2209 98 07:20 ? 00:02:30 postgres: lms > controller [local] SELECT* > lms 2870 2209 0 07:20 ? 00:00:00 postgres: lms controller > [local] SELECT > lms 2871 2209 0 07:20 ? 00:00:00 postgres: lms controller > [local] SELECT > lms 2872 2209 0 07:20 ? 00:00:00 postgres: lms controller > [local] SELECT > *lms 2873 2209 98 07:20 ? 00:02:30 postgres: lms controller > [local] SELECT* > > If you see above, three Select queries have been queued. They are > acquiring CPU only when there is a core without any postgres query running > on it. > > I know the postgres limitation of one query using only one core. But is > there any limitation of one CPU running only one query at a time? > > Are all the queries related to the same table(s)? Which version of PostgreSQL? What's the version of OS? Check out the locks which are not granted yet - pg_locks.granted > Your help is appreciated. > > Thanks and regards, > Vineel. > > -- -- Best Regards Sameer Kumar | DB Solution Architect *ASHNIK PTE. LTD.* 101 Cecil Street, #11-11 Tong Eng Building, Singapore 069 533 T: +65 6438 3504 | M: +65 8110 0350 | www.ashnik.com
