From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
---|---|
To: | "Kaufhold, Christian (LFD)" <Christian(dot)Kaufhold(at)blfd(dot)bayern(dot)de> |
Cc: | pgsql-performance(at)postgresql(dot)org |
Subject: | Re: Query slow after analyse on postgresql 8.2 |
Date: | 2010-06-17 14:58:36 |
Message-ID: | 3775.1276786716@sss.pgh.pa.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-performance |
"Kaufhold, Christian (LFD)" <Christian(dot)Kaufhold(at)blfd(dot)bayern(dot)de> writes:
> I have the following query that I run agains postgresql 8.2:
> ...
> But when I run analyse the same query runs for hours.
Seems like the core of the problem is here:
> -> Seq
> Scan on massnahmeobjekt m (cost=0.00..3271.88 rows=1 width=94) (actual
> time=0.387..577.771 rows=3694 loops=1)
> Filter: ((aktennummer)::text ~* 'M\\-2009\\-1'::text)
If that rowcount estimate weren't off by three orders of magnitude you
probably would be getting a more appropriate plan. The first thing you
could try is increasing the statistics target for aktennummer. Also,
if you're running in a non-C locale and this is 8.2.5 or older, try a
more recent 8.2.x. Updating to 8.3 or 8.4 might help even more.
regards, tom lane
From | Date | Subject | |
---|---|---|---|
Next Message | Kaufhold, Christian (LFD) | 2010-06-17 15:30:25 | Re: Query slow after analyse on postgresql 8.2 |
Previous Message | Dimitri Fontaine | 2010-06-17 11:31:51 | Re: Parallel queries for a web-application |performance testing |