On 16/04/14 17:57, Heikki Linnakangas wrote: > On 04/16/2014 06:13 PM, Linos wrote: >> I thought that Postgresql would optimize out joins on columns I >> don't ask for when I use the view but it doesn't, this query: > > It doesn't, because it would be wrong. It still has to check that the tables have a matching row (or multiple matching rows). > > If you use LEFT JOINs instead, and have a unique index on all the ID columns, then the planner can do what you expected and leave out the joins. > > - Heikki > > You are right, I knew I was forgetting something important but I didn't know what was, thank you Heikki. Regards, Miguel Angel. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
