On Mon, Mar 10, 2008 at 11:36 AM, Peter Eisentraut <[EMAIL PROTECTED]> wrote: > The time to analyze is also quite constant, just before you run out of > memory. :) The MaxAllocSize is the limiting factor in all this. In my > example, statistics targets larger than about 800000 created pg_statistic > rows that would have been larger than 1GB, so they couldn't be stored.
>From my experience on real life examples, the time to analyze is far from being constant when you raise the statistics target but it may be related to the schema of our tables. cityvox=# \timing Timing is on. cityvox=# show default_statistics_target ; default_statistics_target --------------------------- 10 (1 row) Time: 0.101 ms cityvox=# ANALYZE evenement; ANALYZE Time: 406.069 ms cityvox=# ANALYZE evenement; ANALYZE Time: 412.355 ms cityvox=# set default_statistics_target = 30; SET Time: 0.165 ms cityvox=# ANALYZE evenement; ANALYZE Time: 1419.161 ms cityvox=# ANALYZE evenement; ANALYZE Time: 1381.754 ms cityvox=# set default_statistics_target = 100; SET Time: 1.853 ms cityvox=# ANALYZE evenement; ANALYZE Time: 5211.785 ms cityvox=# ANALYZE evenement; ANALYZE Time: 5178.764 ms That said I totally agree that it's not a good idea to have a strict maximum value if we haven't technical reasons for that. -- Guillaume -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers