Re: benchmarking the query planner - Mailing list pgsql-hackers

From Tom Lane
Subject Re: benchmarking the query planner
Date
Msg-id 11419.1229030908@sss.pgh.pa.us
Whole thread Raw
In response to Re: benchmarking the query planner  ("Vladimir Sitnikov" <sitnikov.vladimir@gmail.com>)
Responses Re: benchmarking the query planner  ("Vladimir Sitnikov" <sitnikov.vladimir@gmail.com>)
List pgsql-hackers
"Vladimir Sitnikov" <sitnikov.vladimir@gmail.com> writes:
> One more direction could be implementing "MCV" for range of values (group
> values and interpolate in between). Consider statistics on timestamp column
> that says that for "2008-December" there are as many X rows, for
> "2008-November" as many as Y, etc.  That could be used for rather accurate
> cardinality estimation of "between" cases, while keeping number of entries
> in "MCV" list small.

I think that would likely be redundant with the histogram.
        regards, tom lane


pgsql-hackers by date:

Previous
From: "Vladimir Sitnikov"
Date:
Subject: Re: benchmarking the query planner
Next
From: Simon Riggs
Date:
Subject: Re: Sync Rep: First Thoughts on Code