Re: pretty bad n_distinct estimate, causing HashAgg OOM on TPC-H

From: Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>
To: Feng Tian <ftian(at)vitessedata(dot)com>
Cc: Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: pretty bad n_distinct estimate, causing HashAgg OOM on TPC-H
Date: 2015-06-20 15:36:11
Message-ID: 20150620153611.GY133018@postgresql.org
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Feng Tian wrote:

> I have not read Jeff's patch, but here is how I think hash agg should work,

I think you should discuss that in Jeff's thread, not here.

--
Álvaro Herrera http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

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