Re: Unique Constraint vs Unique Index

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Sun, 6 Jun 1999 11:52:46 +0100
Message-ID: <928666602.14210.0.nnrp-13.9e984b29@news.demon.co.uk>

It's worth remembering that in Oracle 8 (possibly 8.1 only) a unique or pk constrain can be represented by a non-unique index (a) to save space, and (b) to allow for deferring the constraint until commit time.

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

GDN wrote in message <01beb003$0b1a0e40$8909eec3_at_default>...
>When you take a look at the SQL-reference for Oracle 7, you see that the
>"create unique index... " statements doesn't exist any more. You can
>consider it as a hidden feature.
>So, you cannot be sure that it will work in future version of Oracle.
Received on Sun Jun 06 1999 - 05:52:46 CDT