Skip site navigation (1) Skip section navigation (2)

Re: [ADMIN] Out Of Memory 8.1

From: scorpdaddy(at)hotmail(dot)com <scorpdaddy(at)hotmail(dot)com>
To: French, Martin <frenchm(at)cromwell(dot)co(dot)uk>,pgsql-admin(at)postgresql(dot)org
Subject: Re: [ADMIN] Out Of Memory 8.1
Date: 2011-04-07 10:19:35
Message-ID: BLU0-SMTP1942C54EFA45ADFB036D5D9CEA40@phx.gbl (view raw or flat)
Thread:
Lists: pgsql-admin
Have you tried moving the FROM ... WHERE ... into a sub-select? GROUP BY uses HAVING, not WHERE.


----- Reply message -----
From: "French, Martin" <frenchm(at)cromwell(dot)co(dot)uk>
Date: Wed, Apr 6, 2011 7:44 pm
Subject: [ADMIN] Out Of Memory 8.1
To: <pgsql-admin(at)postgresql(dot)org>

Hi All,

I am having problems with a query on 8.1 running on 

RHEL 5.4
16GB RAM
Linux pgsql3 2.6.18-164.el5PAE #1 SMP Tue Aug 18 15:59:11 EDT 2009 i686
i686 i386 GNU/Linux
2 x Xeon X5650 (2.67GHz 6 Cores)
Disks are on PERC 6 controller in RAID 10

Postgresql.conf:
# - Memory -

shared_buffers = 327680         
work_mem = 98394
maintenance_work_mem = 983040

The query:

2011-04-06 23:23:03 BST <app.charisma><26083>LOG:  statement: CREATE
TABLE medusa.cmi_group_free AS	
SELECT	
	stkl_stockno,	
	(SUM(stkphys) - (SUM(stkalloc) + SUM(stkbacko))) as group_free	
FROM	
	charisma.sk_stklfl	
WHERE	
	stkl_stockno NOT LIKE 'ZZ%' AND	
	stkl_stockno ~
'^([A-z&]{2,3})([0-9][0-9][0-9])([0-9][0-9][0-9][0-9][A-z0-9]{1,3})$'	
GROUP BY	
	stkl_stockno;	

The explain (cannot explain analyze, or Postgres runs out of memory
again)
'HashAggregate  (cost=2731947.55..2731947.57 rows=1 width=38)'
'  ->  Seq Scan on stkl_rec  (cost=0.00..2731947.54 rows=1 width=38)'
'        Filter: (((stkl_comp)::text = 'A'::text) AND
((stkl_stockno)::text ~
'^(TK[A-Za-z0-9][0-9]{3}(?:[0-9]{5}(?:[0-9]{3,4})?)?|NSP[0-9]{3}([0-9]{4
})?|Z[MZ][0-9]{8,9}|LSP[0-9]{7}[A-Za-z0-9]|[A-Z][A-Z&][A-Z][0-9]{7}[A-Z0
-9])$'::text) AND ((stkl_stockno)::text !~~ 'ZZ%'::text) AND
((stkl_stockno)::text ~
'^([A-z&]{2,3})([0-9][0-9][0-9])([0-9][0-9][0-9][0-9][A-z0-9]{1,3})$'::t
ext))'

The table has approximately 
6.9 million rows


It's not the OOM that's doing this as vm.overcommit_memory = 2 and
vm.overcommit_ratio = 90 nor is postgres swapping to disk.

Can anyone help me here? The same query on exactly the same data on an
older machine running the same setup except that it's RHEL 5.0 runs
fine!

Thanks.

Martin

___________________________________________________ 
  
This email is intended for the named recipient. The information contained 
in it is confidential.  You should not copy it for any purposes, nor 

Responses

pgsql-admin by date

Next:From: French, MartinDate: 2011-04-07 11:36:01
Subject: Re: Out Of Memory 8.1
Previous:From: Gerhard HintermayerDate: 2011-04-07 09:40:02
Subject: multiple hot standby streaming replication scenario with "rotating" the primary server

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group