Re: GiST for range types (was Re: Range Types - typo + NULL string constructor) - Mailing list pgsql-hackers

From Jeff Davis
Subject Re: GiST for range types (was Re: Range Types - typo + NULL string constructor)
Date
Msg-id 1320309749.32341.27.camel@jdavis
Whole thread Raw
In response to Re: GiST for range types (was Re: Range Types - typo + NULL string constructor)  (Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>)
List pgsql-hackers
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.

Regards,Jeff Davis



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