Re: Hash Join cost estimates

From: Stephen Frost <sfrost(at)snowman(dot)net>
To: Jeff Davis <pgsql(at)j-davis(dot)com>
Cc: pgsql-hackers(at)postgresql(dot)org
Subject: Re: Hash Join cost estimates
Date: 2013-03-30 20:15:25
Message-ID: 20130330201525.GY4361@tamriel.snowman.net
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Jeff,

* Jeff Davis (pgsql(at)j-davis(dot)com) wrote:
> On Thu, 2013-03-28 at 19:56 -0400, Stephen Frost wrote:
> > 41K hashed, seqscan 4M: 115030.10 + 1229.46 = 116259.56
> > 4M hashed, seqscan 41K: 1229.46 + 211156.20 = 212385.66
>
> I think those are backwards -- typo?

Yes, sorry, those are backwards. The '4M hashed, seqscan 41K' entry
comes out with the lower cost and that's what we end up using.

Thanks,

Stephen

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