Thanks Tom, alter table boden.massnahmeobjekt alter column aktennummer set statistics 1000; fixed it. Regards Christian -----Ursprüngliche Nachricht----- Von: pgsql-performance-owner@xxxxxxxxxxxxxx [mailto:pgsql-performance-owner@xxxxxxxxxxxxxx] Im Auftrag von Tom Lane Gesendet: Donnerstag, 17. Juni 2010 16:59 An: Kaufhold, Christian (LFD) Cc: pgsql-performance@xxxxxxxxxxxxxx Betreff: Re: Query slow after analyse on postgresql 8.2 "Kaufhold, Christian (LFD)" <Christian.Kaufhold@xxxxxxxxxxxxxx> 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 -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
