Re: Foreign key constraints

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Fri, 18 Jun 1999 16:53:53 +0100
Message-ID: <929721964.20002.0.nnrp-12.9e984b29@news.demon.co.uk>

Yes, of course.

Sincere apologies to the newsgroup for
putting out spreading confusion. Please ignore (most of) my previous post on
FK constraints.

One more silly error and I'm going to
retire, I think.

I must have explained this dozens of times - clearly the child table has to be locked to stop another user from sneaking in an
orphan after the parent is deleted but
before the commit takes place. It's
a consequence of read-consistency and
readers not blocking writers.

(actually, in parent/child RI processing Oracle is doing a sneaky bit of read-uncommitted, but only for internal consumption so it's not really cheating).

Jonathan Lewis
Yet another Oracle-related web site: www.jlcomp.demon.co.uk

Thomas Kyte wrote in message <3774581b.9746885_at_newshost.us.oracle.com>...
>A copy of this was sent to "Jonathan Lewis" <jonathan_at_jlcomp.demon.co.uk>
>(if that email address didn't require changing)
>On Fri, 18 Jun 1999 14:58:27 +0100, you wrote:
>
>you got that backwards. The child table is locked (we are going to full
scan it
>anyhow)
>
Received on Fri Jun 18 1999 - 10:53:53 CDT