Skip site navigation (1)
Skip section navigation (2)
Peripheral Links
Header And Logo
|
Site Navigation
Re: Expected accuracy of planner statistics
- From: "John D. Burger" <john(at)mitre(dot)org>
- To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
- Cc: Postgres General <pgsql-general(at)postgresql(dot)org>
- Subject: Re: Expected accuracy of planner statistics
- Date: Fri, 29 Sep 2006 10:53:21 -0400
Tom Lane wrote:
The information we've seen says that the only statistically reliable wayto arrive at an accurate n_distinct estimate is to examine most of the table :-(.
IIRC I picked an equation out of the literature partially on the basis of it being simple and fairly cheap to compute...
I'm very curious about this - can you recall where you got this, or at least point me to where in the code this happens?
Thanks. - John Burger MITRE
- Follow-Ups:
- Re: Expected accuracy of planner statistics
- From: Tom Lane
- Re: Expected accuracy of planner statistics
- References:
- Expected accuracy of planner statistics
- From: Casey Duncan
- Re: Expected accuracy of planner statistics
- From: Tom Lane
- Expected accuracy of planner statistics
- Prev by Date: Re: 8.1.4 compile problem
- Next by Date: Re: 8.1.4 compile problem
- Previous by thread: Re: Expected accuracy of planner statistics
- Next by thread: Re: Expected accuracy of planner statistics
- Indexes: