Thread

Re: [HACKERS] subselect and optimizer

Boersenspielteam <boersenspiel@vocalweb.de> — 1998-04-11T12:27:01Z

> > 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