Re: How are foreign keys stored in 7.1?

From: Tom Remisoski <remisosk>
Date: 1995/07/19
Message-ID: <3ujr1v$504_at_cass.ma02.bull.com>#1/1


sehlke_at_cts.com (Steve Ehlke) wrote:
>I need to find out how foreign keys are stored in a table. Does
>Oracle make a copy of the other tables primary key, or does it use a
>pointer of some sort like ROWID? Eample: If Table A's primary key is
>50 bytes and table B uses this as a foreign key, is 50 bytes used for
>storing the foreign key?

Table B will require a column to store the key in. It should be the same size as the column it is referencing. An index on the column in table B will be helpful from a locking standpoint if you're doing a lot of online updates to table A (see the Application Developer's Guide pp. 6-6..6-11).

-- 
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Tom Remisoski                                (remisosk_at_forklift.mi04.zds.com)
Database Analyst                                (T.Remisoski_at_zds.com)
Zenith Data Systems
Received on Wed Jul 19 1995 - 00:00:00 CEST

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