From: Tom Lane <tgl@sss.pgh.pa.us>
To: Dean Rasheed <dean.a.rasheed@gmail.com>
cc: Alvaro Herrera <alvherre@2ndquadrant.com>,
        Tomas Vondra <tomas.vondra@2ndquadrant.com>,
        Alexander Korotkov <a.korotkov@postgrespro.ru>,
        Mark Dilger <hornschnorter@gmail.com>,
        PostgreSQL-development <pgsql-hackers@postgresql.org>
Subject: Re: improving GROUP BY estimation
In-reply-to: 
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References: <20160331205118.GA166096@alvherre.pgsql>
 <8033.1459458176@sss.pgh.pa.us>
 <CAEZATCVkTeN6fLvhcp=0EeKK091NCyOcO1mh9Znnk5GQp=N1+w@mail.gmail.com>
Comments: In-reply-to Dean Rasheed <dean.a.rasheed@gmail.com>
	message dated "Sat, 02 Apr 2016 13:20:13 +0100"
Date: Sat, 02 Apr 2016 10:59:16 -0400
Message-ID: <31529.1459609156@sss.pgh.pa.us>
Precedence: bulk
Sender: pgsql-hackers-owner@postgresql.org

Dean Rasheed <dean.a.rasheed@gmail.com> writes:
> Here's an updated patch with references to both papers, and a more
> detailed justification for the formula, along with the other changes
> discussed. Note that although equation (2) in the Dell'Era paper looks
> different from the Yao formula, it's actually the same.

Looks good to me.

			regards, tom lane


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