Thread: Question about Generating Possible Plans by the planner/optimizer
in the docummentation about the planer it says: "It first combines all possible ways of scanning and joining the relations that appear in a query" I would like to know if there's a time limit to do that or if it just scans ALL the posibilities until it finishes..no matter the time it takes.. thanks in advance. _________________________________________________________________ MSN Amor: busca tu ½ naranja http://latam.msn.com/amor/
Re: Question about Generating Possible Plans by the planner/optimizer
From
"Steinar H. Gunderson"
Date:
On Fri, Aug 06, 2004 at 07:28:38PM -0500, sandra ruiz wrote: > in the docummentation about the planer it says: > > "It first combines all possible ways of scanning and joining the relations > that appear in a query" > > I would like to know if there's a time limit to do that or if it just scans > ALL the posibilities until it finishes..no matter the time it takes.. Depends; if you join a lot of tables, it stops doing an exhaustive search and goes for genetic optimization instead: http://www.postgresql.org/docs/7.4/static/geqo.html /* Steinar */ -- Homepage: http://www.sesse.net/