Re: [HACKERS] subselect and optimizer
Boersenspielteam <boersenspiel@vocalweb.de>
From: "Boersenspielteam" <boersenspiel@vocalweb.de>
To: Bruce Momjian <maillist@candle.pha.pa.us>
Cc: hackers@postgreSQL.org
Date: 1998-04-11T12:27:01Z
Lists: pgsql-hackers
> > But this patch still didn't help for a simple join without a where > > clause. The query plan says it uses two sequential scans, where 6.2.1 > > uses two index scans. > > But we didn't have subselcts in 6.2.1? No, but in the more general case of a simple join over two tables with fields with an index declared on them. say: Select * from Trans, Spieler where Spieler.spieler_nr=Trans.spieler_nr Uses indices in 6.2.1, doesn't use them in 6.3.1 (two seq scans). I just wanted to remind you, that these problems are not restricted to subqueries, but seem to be a more general 'flaw' in 6.3.x . Hope this helps. Ulrich