>>>-----Messaggio originale----- >>>Da: Tom Lane [mailto:[EMAIL PROTECTED] >>>Inviato: giovedì 13 maggio 2004 17.01 >>>A: Fabio Panizzutti >>>Cc: 'Shridhar Daithankar'; [EMAIL PROTECTED] >>>Oggetto: Re: R: [PERFORM] Query plan on identical tables >>>differs . Why ? >>> >>> >>>"Fabio Panizzutti" <[EMAIL PROTECTED]> writes: >>>> I don't understand why the planner chose a different query plan on >>>> identical tables with same indexes . >>> >>>Different data statistics; not to mention different table >>>sizes (the cost equations are not linear). >>> >>>Have you ANALYZEd (or VACUUM ANALYZEd) both tables recently? >>> >>>If the stats are up to date but still not doing the right >>>thing, you might try increasing the statistics target for >>>the larger table's tag_id column. See ALTER TABLE SET STATISTICS. >>> >>> regards, tom lane >>>
All tables are vacumed and analyzed . I try so set statistics to 1000 to tag_id columns with ALTER TABLE SET STATISTIC, revacuum analyze , but the planner choose the same query plan . I'm trying now to change the indexes . Thanks ---------------------------(end of broadcast)--------------------------- TIP 8: explain analyze is your friend
