Jesper Krogh <jes...@krogh.cc> writes: > When something evaluates to "null" isn't included in the result, > shouldn't the query-planner > then take the null_frac into account when computing the estimate?
The proposed patch seems wrong to me: if we're estimating on the basis of most-common-value fractions, the null_frac is already accounted for, because it's not part of the MCV selectivity fractions. IOW, aren't you double-counting the null fraction? regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers