On Mon, Jun 13, 2011 at 6:33 PM, Willy-Bas Loos <willybas@xxxxxxxxx> wrote: > On Fri, Jun 10, 2011 at 9:58 PM, Josh Berkus <josh@xxxxxxxxxxxx> wrote: >> >> It's not 10%. We use a fixed sample size, which is configurable on the >> system, table, or column basis. > > It seems that you are referring to "alter column set statistics" and > "default_statistics_target", which are the number of percentiles in the > histogram (and MCV's) . > I mean the number of records that are scanned by analyze to come to the > statistics for the planner, especially n_disctict. In 9.0+ you can do ALTER TABLE .. ALTER COLUMN .. SET (n_distinct = ...); -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
