Re: [HACKERS] Estimates not taking null_frac element into account with @@ operator? (8.4 .. git-head)

2011-02-17 Thread Tom Lane
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

Re: [HACKERS] Estimates not taking null_frac element into account with @@ operator? (8.4 .. git-head)

2011-02-17 Thread Jesper Krogh
On 2011-02-17 23:20, Tom Lane wrote: Jesper Kroghjes...@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

Re: [HACKERS] Estimates not taking null_frac element into account with @@ operator? (8.4 .. git-head)

2011-02-17 Thread Tom Lane
Jesper Krogh jes...@krogh.cc writes: On 2011-02-17 23:20, Tom Lane wrote: 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

Re: [HACKERS] Estimates not taking null_frac element into account with @@ operator? (8.4 .. git-head)

2011-02-17 Thread Tom Lane
Jesper Krogh jes...@krogh.cc writes: Attached patch tries to align the behaviour Applied with a bit of editorialization. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: