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Cc: "Evgeny Shishkin" <itparanoia@gmail.com>,"Tom Lane"
	<tgl@sss.pgh.pa.us>,"Andrew Dunstan" <andrew@dunslane.net>,"postgres
	performance list" <pgsql-performance@postgresql.org>
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Date: Fri, 14 Dec 2012 14:14:27 -0500
From: "Kevin Grittner" <kgrittn@mail.com>
Message-ID: <20121214191427.80090@gmx.com>
MIME-Version: 1.0
Subject: Re: Why does the number of rows are different in actual and
 estimated.
To: "AI Rumman" <rummandba@gmail.com>,
	"Claudio Freire" <klaussfreire@gmail.com>
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AI Rumman wrote:
> Claudio Freire <klaussfreire@gmail.com>wrote:
>> I think it's more likely a missing FK constraint.

> Does FK Constraint help to improve performance? Or it is only
> for maintaining data integrity?

I'm not aware of any situation where adding a foreign key
constraint would improve performance.

-Kevin


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