On Sat, Jun 28, 2008 at 10:53 AM, Tom Lane <[EMAIL PROTECTED]> wrote: > Ulrich <[EMAIL PROTECTED]> writes: >> People say that [EXISTS is faster] > > People who say that are not reliable authorities, at least as far as > Postgres is concerned. But it is always a bad idea to extrapolate > results on toy tables to large tables --- quite aside from measurement > noise and caching issues, the planner might pick a different plan when > faced with large tables. Load up a realistic amount of data and then > see what you get. >
i've made some queries run faster using EXISTS instead of large IN clauses... actually, it was NOT EXISTS replacing a NOT IN while i'm not telling EXISTS is better i actually know in some cases is better -- Atentamente, Jaime Casanova Soporte y capacitación de PostgreSQL Guayaquil - Ecuador Cel. (593) 87171157 -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
