I am not sure what you mean by reformulate the data representation. Do you mean do I have to join on all three columns?
-----Original Message----- From: Tom Lane [mailto:t...@sss.pgh.pa.us] Sent: Friday, October 29, 2010 2:18 PM To: Ozer, Pam Cc: pgsql-performance@postgresql.org Subject: Re: [PERFORM] Slow Query- Bad Row Estimate "Ozer, Pam" <po...@automotive.com> writes: > Unfortunately I have not received a response on this question. Is more > information needed? Does anyone have any ideas why the estimates may be > bad? Or what I might be able to do to speed this up? The most likely explanation for the bad rowcount estimates is that there is correlation between the regionid/countyid/cityid columns, only the planner doesn't know it. Can you reformulate that data representation at all, or at least avoid depending on it as a join key? regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
