From: | Richard Huxton <dev(at)archonet(dot)com> |
---|---|
To: | "Mindaugas Riauba" <mind(at)bi(dot)lt>, <pgsql-performance(at)postgresql(dot)org> |
Subject: | Re: Need advice about triggers |
Date: | 2003-09-09 14:40:51 |
Message-ID: | 200309091540.51382.dev@archonet.com |
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Lists: | pgsql-performance |
On Tuesday 09 September 2003 14:33, Mindaugas Riauba wrote:
> > Well, try it without the trigger. If performance improves markedly, it
> might
> > be worth rewriting in C.
>
> Nope. Execution time is practically the same without trigger.
OK - no point in rewriting it then.
> > If not, you're probably saturating the disk I/O - using iostat/vmstat
> > will
>
> let
>
> > you see what's happening. If it is your disks, you might see if moving
> > the WAL onto a separate drive would help, or check the archives for
> > plenty of discussion about raid setups.
>
> Bottleneck in this case is CPU. postmaster process uses almost 100% of
> CPU.
> Disk I/O should not be a problem in this case. vmstat shows ~300kb/s
> write activity.
Hmm - I must admit I wasn't expecting that. Closest I can get on my test
machine here: AMD 400MHz / 256MB / IDE disk / other stuff running is about 20
secs.
I've attached the perl script I used - what sort of timings does it give you?
--
Richard Huxton
Archonet Ltd
Attachment | Content-Type | Size |
---|---|---|
big_update_test.pl | text/x-perl | 1.3 KB |
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