Re: [PERFORM] parallel query evaluation

2012-11-10 Thread Tom Lane
Oliver Seidel writes: > I have > create table x ( att bigint, val bigint, hash varchar(30) > ); > with 693million rows. The query > create table y as select att, val, count(*) as cnt from x > group by att, val; > ran for more than 2000 minutes and used 14g memory on

Re: [PERFORM] Re: Increasing work_mem and shared_buffers on Postgres 9.2 significantly slows down queries

2012-11-10 Thread Petr Praus
On 6 November 2012 14:50, Gunnar "Nick" Bluth wrote: > Am 06.11.2012 21:24, schrieb Petr Praus: > > On 6 November 2012 14:17, Gunnar "Nick" Bluth wrote: > >> Am 06.11.2012 21:08, schrieb Petr Praus: >> >> >>> 2MB: http://explain.depesz.com/s/ul1 >>> 4MB: http://explain.depesz.com/s/IlVu >>> 10MB:

[PERFORM] parallel query evaluation

2012-11-10 Thread Oliver Seidel
Hi, I have create table x ( att bigint, val bigint, hash varchar(30) ); with 693million rows. The query create table y as select att, val, count(*) as cnt from x group by att, val; ran for more than 2000 minutes and used 14g memory on an 8g physical RAM machine -

Re: [PERFORM] Query completed in < 1s in PG 9.1 and ~ 700s in PG 9.2

2012-11-10 Thread aasat
Please try LIMIT 1 in exists exists(select id from condition_document_excerpt where condition_id=c1686.id LIMIT 1) as v1686_has_reference -- View this message in context: http://postgresql.1045698.n5.nabble.com/Query-completed-in-1s-in-PG-9-1-and-700s-in-PG-9-2-tp5730899p5731021.html Sent fro

Re: [PERFORM] Re: Increasing work_mem and shared_buffers on Postgres 9.2 significantly slows down queries

2012-11-10 Thread Petr Praus
On 4 November 2012 02:48, Gunnar "Nick" Bluth wrote: > Am 03.11.2012 18:19, schrieb Petr Praus: > > On 3 November 2012 12:09, Gunnar "Nick" Bluth wrote: > >> Am 03.11.2012 16:20, schrieb Petr Praus: >> >> >>Your CPUs are indeed pretty oldschool. FSB based, IIRC, not NUMA. A >>> process migra

Re: [PERFORM] Re: Increasing work_mem and shared_buffers on Postgres 9.2 significantly slows down queries

2012-11-10 Thread Petr Praus
On 6 November 2012 13:38, Gunnar "Nick" Bluth wrote: > Am 06.11.2012 18:38, schrieb Petr Praus: > > > Yes, but note that this happens only in Linux. Increasing work_mem on my > iMac increases performance (but the queries are slower under OSX than on > virtualized Ubuntu on the same machine). Ove

Re: [PERFORM] Re: Increasing work_mem and shared_buffers on Postgres 9.2 significantly slows down queries

2012-11-10 Thread Petr Praus
On 6 November 2012 14:17, Gunnar "Nick" Bluth wrote: > Am 06.11.2012 21:08, schrieb Petr Praus: > > >> 2MB: http://explain.depesz.com/s/**ul1 >> 4MB: http://explain.depesz.com/s/**IlVu >> 10MB: http://explain.depesz.com/s/**afx3