Re: Sequential scan on FK join

Subject:      Re: Sequential scan on FK join
From:         Martin Nickel <martin@portant.com>
Newsgroups:   pgsql.performance
Date:         Wed, 12 Oct 2005 15:53:35 -0500

Richard, here's the EXPLAIN ANALYZE.  I see your point re: the 2.7M
expected vs the 2 actual, but I've run ANALYZE on the lead table and it
hasn't changed the plan.  Suggestions?

"Hash Join  (cost=62.13..2001702.55 rows=2711552 width=20) (actual
time=40.659..244709.315 rows=2    125270 loops=1)" "  Hash Cond:
("outer".mailing_id = "inner".mailing_id)" "  ->  Seq Scan on lead l
(cost=0.00..1804198.60 rows=34065260 width=8) (actual
time=8.621..180281.094 rows=34060373 loops=1)" "  ->  Hash
(cost=61.22..61.22 rows=362 width=20) (actual time=28.718..28.718 rows=0
loops=1)" "        ->  Index Scan using mailing_maildate_idx on mailing m
(cost=0.00..61.22 rows=362 width=20) (actual time=16.571..27.793 rows=430
loops=1)" "              Index Cond: ((maildate >= '2005-07-01'::date) AND
(maildate < '2005-08-01'::date))" "Total runtime: 248104.339 ms"