Re: Slow update statement

From: Patrick Hatcher <pathat(at)comcast(dot)net>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: John A Meinel <john(at)arbash-meinel(dot)com>, "pgsql-performance(at)postgresql(dot)org" <pgsql-performance(at)postgresql(dot)org>
Subject: Re: Slow update statement
Date: 2005-08-08 04:35:36
Message-ID: 42F6E118.20206@comcast.net
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-performance

At the time this was the only process running on the box so I set
sort_mem= 228000;
It's a 12G box.

Tom Lane wrote:

>Patrick Hatcher <pathat(at)comcast(dot)net> writes:
>
>
>> Hash Join (cost=1246688.42..4127248.31 rows=12702676 width=200)
>> Hash Cond: ("outer".cus_num = "inner".cus_nbr)
>> -> Seq Scan on bcp_ddw_ck_cus b (cost=0.00..195690.76 rows=12702676
>>width=16)
>> -> Hash (cost=874854.34..874854.34 rows=12880834 width=192)
>> -> Seq Scan on cdm_ddw_customer (cost=0.00..874854.34
>>rows=12880834 width=192)
>>
>>
>
>Yipes, that's a bit of a large hash table, if the planner's estimates
>are on-target. What do you have work_mem (sort_mem if pre 8.0) set to,
>and how does that compare to actual available RAM? I'm thinking you
>might have set work_mem too large and the thing is now swap-thrashing.
>
> regards, tom lane
>
>
>

In response to

Browse pgsql-performance by date

  From Date Subject
Next Message Kari Lavikka 2005-08-08 12:03:21 Re: Finding bottleneck
Previous Message Tom Lane 2005-08-08 03:48:25 Re: Slow update statement