RE: [Q] what difference between PK and unique index + not NULL??

From: Powell, Mark D <mark.powell_at_eds.com>
Date: Tue, 18 Jan 2005 14:24:13 -0500
Message-ID: <5A14AF34CFF8AD44A44891F7C9FF410511E738@usahm236.amer.corp.eds.com>

The definition of a PK constraint is that it is a UK constraint plus the "not null" constraint. Indexing is a technical implementation issue and is not really part of the PK definition. After all Oracle can from verion 8 up use non-unique indexes to implement PK constraints.

-----Original Message-----

From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org]On Behalf Of dba1 mcc Sent: Tuesday, January 18, 2005 1:59 PM
To: oracle-l_at_freelists.org
Subject: [Q] what difference between PK and unique index + not NULL??

I have some argued with contractor about Primary key and Unique index + Not NULL. Contractor said Primary Key = (field specify NOT NLL and create unique index ..). I rember some documents say Primary Key and (unique index, not null) still some different.

Does anyone have opinion?

Thanks.                 

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http://www.freelists.org/webpage/oracle-l Received on Tue Jan 18 2005 - 22:19:15 CST