On Wednesday 26 November 2003 18:39, Roger Ging wrote: > version 7.4 results: > > explain analyse SELECT L.row_id FROM music.logfile L LEFT JOIN > music.program P ON > music.fn_mri_id_no_program(P.mri_id_no) = L.program_id > WHERE L.station = UPPER('kabc')::VARCHAR > AND L.air_date = '04/12/2002'::TIMESTAMP > AND P.cutoff_date IS NULL > ORDER BY L.chron_start,L.chron_end;
> -> Seq Scan on program p (cost=0.00..15192.35 > rows=4335 width=20) (actual time=109.045..1955.882 rows=173998 loops=1) The estimated number of rows here (4335) is *way* off (173998 actually). If you only had 4335 rows, then this might be a more sensible plan. First step is to run: VACUUM ANALYSE program; Then, check the definition of your function fn_mri_id_no_program() and make sure it is marked immutable/stable (depending on what it does) and that it's returning a varchar. -- Richard Huxton Archonet Ltd ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html