RE: Unindexed foreign key

From: Freeman, Robert <Robert_Freeman_at_csx.com>
Date: Thu, 18 Jul 2002 11:43:37 -0800
Message-ID: <F001.0049BCF8.20020718114337@fatcity.com>

Well, that depends on if the FK is enforced or not too. There should be minimal
performance impact with an unenforced FK with regards to inserts. In a DW FK's are often present but not enforced. Unenforced FK's in DW's are used for a number of reasons, query rewrite among them.

Some of the old performance and locking issues with FK's were done away with in 9i.

What

Robert G. Freeman - Oracle OCP
Oracle Database Architect
CSX Midtier Database Administration
Author
Oracle9i RMAN Backup and Recovery (Oracle Press - Oct 2002) Oracle9i New Features (Oracle Press)
Mastering Oracle8i  (Sybex)

Clark Griswold: Eddie, has anyone ever told you that you're bad luck? Cousin Eddie: Those were my mother's dying words. But I guess if your body's covered in third degree burns, and your foot's caught in a bear trap, you tend to start talkin' crazy.

-----Original Message-----
Sent: Thursday, July 18, 2002 2:44 PM
To: Multiple recipients of list ORACLE-L

Terrible expecially on inserts into the database, it may have to do a full table scan to insert one record. Don't do it.

>From: "Shishir Kumar Mishra" <shishir_at_agnisoft.com>
>Reply-To: ORACLE-L_at_fatcity.com
>To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
>Subject: Unindexed foreign key
>Date: Thu, 11 Jul 2002 04:13:36 -0800
>
>Hi Gurus!
>How does the unindexed foreign key affect the performance ?
>
>regards....
>Shishir Kumar Mishra
>Agni Software (P) Ltd.
>www.agnisoft.com
>----------------------------------
>Vidya Dadaati Viniyam
>----------------------------------
>
>

Over and out Basher 59

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Received on Thu Jul 18 2002 - 14:43:37 CDT