Date: Mon, 9 May 2005 11:51:33 -0500
From: "Jim C. Nasby" <decibel@decibel.org>
To: Neil Conway <neilc@samurai.com>
Cc: Christopher Petrilli <petrilli@gmail.com>,
	Ying Lu <ying_lu@cs.concordia.ca>, pgsql-general@postgresql.org,
	pgsql-performance@postgresql.org
Subject: Re: [PERFORM] "Hash index" vs. "b-tree index" (PostgreSQL
Message-ID: <20050509165133.GJ35026@decibel.org>
References: <427F6853.90308@cs.concordia.ca> <427F757A.8000407@samurai.com>
	<59d991c405050908271b55e673@mail.gmail.com>
	<427F8321.5030702@samurai.com> <20050509163423.GH35026@decibel.org>
	<427F9211.2090008@samurai.com>
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On Tue, May 10, 2005 at 02:38:41AM +1000, Neil Conway wrote:
> Jim C. Nasby wrote:
> >Having indexes that people shouldn't be using does add confusion for
> >users, and presents the opportunity for foot-shooting.
> 
> Emitting a warning/notice on hash-index creation is something I've 
> suggested in the past -- that would be fine with me.

Probably not a bad idea.

> >Even if there is some kind of advantage (would they possibly speed up
> >hash joins?)
> 
> No, hash joins and hash indexes are unrelated.

I know they are now, but does that have to be the case? Like I said, I
don't know the history, so I don't know why we even have them to begin
with.
-- 
Jim C. Nasby, Database Consultant               decibel@decibel.org 
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