On Wed, Nov 5, 2008 at 11:52 AM, Andrus <kobruleht2@xxxxxx> wrote: > I have table with index > > CREATE TABLE firma2.dok( > ... > dokumnr serial NOT NULL, > ... > CONSTRAINT dok_pkey PRIMARY KEY (dokumnr), > ... > ); > > CREATE INDEX dok_dokumnr_idx > ON firma2.dok > USING btree > (dokumnr); > > I ran analyze command on it. > > explain analyze select * from firma2.dok where dokumnr='1228137'::float8 > > "Seq Scan on dok (cost=0.00..187766.23 rows=6255 width=1145) (actual > time=43168.460..43176.063 rows=1 loops=1)" > " Filter: ((dokumnr)::double precision = 1228137::double precision)" > "Total runtime: 43176.375 ms" > > shows that index is not used and thus query takes very long time. > > How to force PostgreSql to speed up without changing query ? Stop trying to compare exact and inexact types? You do realize that a float is not an exact number. What you and I see as 1228137 might really be, internally, 1228136.9999999999999999 ? So it won't get an exact match. What's wrong with trying to match to an exact number instead? I have a feeling you've given us a simplified example of your problem. It might help to see the real problem. -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
