Re: all foreign key should have index?
From: Murdoc <murdoc_0_at_hotmail.com>
Date: Tue, 31 Jan 2006 20:20:44 +0000 (UTC)
Message-ID: <xn0ehygzyh014000_at_news-south.connect.com.au>
Date: Tue, 31 Jan 2006 20:20:44 +0000 (UTC)
Message-ID: <xn0ehygzyh014000_at_news-south.connect.com.au>
Tony Rogerson wrote:
> > No. But better SQL products construct a "PK=FK" index under the
> > covers for you.
>
> Do you have a list of those?
MySQL for one.
> Is it configurable? I'm not sure I want my rdbms generating a 5GB index on my foreign key when I
> might not require it.
The indexes are usually created to aid in the Cascading or Restricting of deletes and updates.
Regards,
Murdoc
--Received on Tue Jan 31 2006 - 21:20:44 CET