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Re: will foreign key improve select query performance

From: Chris <dmagick(at)gmail(dot)com>
To: petchimuthu lingam <spmlingam(at)gmail(dot)com>
Cc: pgsql-php(at)postgresql(dot)org
Subject: Re: will foreign key improve select query performance
Date: 2008-03-07 04:26:23
Message-ID: 47D0C3EF.9030501@gmail.com (view raw or flat)
Thread:
Lists: pgsql-php
petchimuthu lingam wrote:
> If i create foreign key references, whether it will improve the 
> performance in the select query?

Foreign keys are used to create integrity in the database, it won't 
affect select performance.

eg:

create table users (
   userid int primary key,
   username text
);

create table news (
   newsid int primary key,
   created_by int references users(userid)
);

That means that a news item cannot be created by a userid that doesn't 
exist.

http://www.postgresql.org/docs/current/interactive/tutorial-fk.html

-- 
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http://www.designmagick.com/

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