Wondering if Update firma1.rid set toode=null where toode is not null and not exists(select 1 from firma1.toode where toode=rid.toode); Would be faster... Problem appears to be the seqscan of seqscan... No? > -----Original Message----- > From: pgsql-performance-owner@xxxxxxxxxxxxxx > [mailto:pgsql-performance-owner@xxxxxxxxxxxxxx] On Behalf Of > Scott Marlowe > Sent: Tuesday, April 04, 2006 3:49 PM > To: Andrus > Cc: pgsql-performance@xxxxxxxxxxxxxx > Subject: Re: [PERFORM] Query runs too long for indexed tables > > On Tue, 2006-04-04 at 14:37, Andrus wrote: > > I have relatively small tables (toode and rid) in fast server. > > Both tables are indexed on toode field. > > > > Following query takes long time to run. > > toode field type is char(20). It is difficult to change > this field type. > > > > Any idea how to speed up this query ? > > > > UPDATE firma1.rid SET toode=NULL > > WHERE toode IS NOT NULL AND > > toode NOT IN (SELECT TOODE FROM firma1.TOODE); > > > > Query returned successfully: 0 rows affected, 594813 ms > execution time. > > > > explain window shows: > > > > Seq Scan on rid (cost=2581.07..20862553.77 rows=51848 width=1207) > > Filter: ((toode IS NOT NULL) AND (NOT (subplan))) > > SubPlan > > -> Materialize (cost=2581.07..2944.41 rows=14734 width=84) > > -> Seq Scan on toode (cost=0.00..2350.34 rows=14734 > > width=84) > > Let me guess, you've updated it a lot and aren't familiar with Vacuum? > > run a vacuum full on your database. schedule a vacuum (plain > one) to run every so often (hours or days are a good interval > for most folks) > > If that's NOT your problem, then please, let us know. > > ---------------------------(end of > broadcast)--------------------------- > TIP 2: Don't 'kill -9' the postmaster >
