Re: Database Foreign key constraints vs Application Maintained Constraints

From: Jared Still <>
Date: Mon, 20 Apr 2009 20:20:22 -0700
Message-ID: <>

 On Mon, Apr 20, 2009 at 12:53 PM, peter bell <> wrote:

> I'm looking for thoughts / feedback / experiences of :
> - applications that leave enforcement of foreign key relationships to the
> application (or simply assume that those relationships will not be violated)
> in an OLTP system

Experiences are that developers cannot possibly enforce constraints on their data.

The assumption is that data will only be updated, inserted or deleted by their application, and that is never true.

There's a host of technical reasons, but I think that one business reason should be sufficient to see why the technical reasons are valid.

One of my favorite database quotes is from "A Practical Guide to Logical Data Modeling" by George Tillmann

Why is data modeling needed?
The main reason is that system developers are so bad at building files and databases.

If the project goes ahead, it will be good news for highly paid Oracle Performance Analysts.

Jared Still
Certifiable Oracle DBA and Part Time Perl Evangelist

Received on Mon Apr 20 2009 - 22:20:22 CDT

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