Re: Statistics and selectivity estimation for ranges - Mailing list pgsql-hackers

From Alexander Korotkov
Subject Re: Statistics and selectivity estimation for ranges
Date
Msg-id CAPpHfdtMUSF64MaRNn+fxMZxmN_BmGftTfUYn3=3MoDo1saDLQ@mail.gmail.com
Whole thread Raw
In response to Re: Statistics and selectivity estimation for ranges  (Alexander Korotkov <aekorotkov@gmail.com>)
Responses Re: Statistics and selectivity estimation for ranges
List pgsql-hackers
On Thu, Aug 9, 2012 at 12:44 AM, Alexander Korotkov <aekorotkov@gmail.com> wrote:
My conclusion is so, that current errors are probably ok for selectivity estimation. But taking into attention that generated datasets ideally fits assumptions of estimation, there could be room for improvement. Especially, it's unclear why estimate for "<@" and "@>" have much greater error than estimate for "&&". Possibly, it's caused by some bugs.

ITSM, I found reason of inaccuracy. Implementation of linear interpolation was wrong. Fixed version is attached. Now, need to rerun tests, possible refactoring and comments rework.
 
------
With best regards,
Alexander Korotkov.
Attachment

pgsql-hackers by date:

Previous
From: Tom Lane
Date:
Subject: Re: default_isolation_level='serializable' crashes on Windows
Next
From: Peter Eisentraut
Date:
Subject: Re: error handling in logging hooks