Re: GiST for range types (was Re: Range Types - typo + NULL string constructor)
От | Heikki Linnakangas |
---|---|
Тема | Re: GiST for range types (was Re: Range Types - typo + NULL string constructor) |
Дата | |
Msg-id | 4EB2823C.4010701@enterprisedb.com обсуждение исходный текст |
Ответ на | GiST for range types (was Re: Range Types - typo + NULL string constructor) (Alexander Korotkov <aekorotkov@gmail.com>) |
Ответы |
Re: GiST for range types (was Re: Range Types - typo +
NULL string constructor)
Re: GiST for range types (was Re: Range Types - typo + NULL string constructor) |
Список | pgsql-hackers |
On 03.11.2011 10:42, Jeff Davis wrote: > On Wed, 2011-11-02 at 22:59 +0200, Heikki Linnakangas wrote: >> This seems to be coming from the selectivity estimation function. The >> selectivity function for<@ is scalargtsel, which is usually used for >> scalar> and>=. That doesn't seem right. But what do we store in the >> statistics for range types in the first place, and what would be the >> right thing to do for selectivity estimation? > > I'll have to think more about that, and it depends on the operator. It > seems like an easier problem for "contains a point" than "contains > another range" or "overlaps with another range". > > Right now I don't have a very good answer, and even for the "contains a > point" case I'll have to think about the representation in pg_statistic. I've committed this now, after some more cleanup. I removed the selectivity estimation functions from operators where they were bogus, so writing those is a clear TODO. But that can well be done as a separate patch. Thanks! -- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com
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