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Re: (Non)Unique Index Vs Unique Constraint

From: GovindanK <gkatteri_at_fastmail.fm>
Date: Thu, 22 Jan 2004 15:39:25 -0800
Message-ID: <F001.005DDEAB.20040122153925@fatcity.com>


Add this to what Arup said:

PK enables one to have References established in a schema. (Parent Child relationships i mean). That cannot be done just by having a unique and/or
not null constraints set.
You will get ORA-02270: no matching unique or primary key for this column-list

HTH
GovindanK

On Sat, 17 Jan 2004 20:49:25 -0800, "Arup Nanda" <orarup_at_hotmail.com> said:
> Jay,
>
> Remember, both UK and PK are enforced by unique indexes. The important
> difference between them is a null value is allowed in UK, not in PK.
>

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Received on Thu Jan 22 2004 - 17:39:25 CST

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