Re: FOREIGN KEY constraint

From: Tony Jambu <aaj_at_cmutual.com.au>
Date: Tue, 3 May 1994 06:01:43 GMT
Message-ID: <Cp7q2w.KKn_at_cmutual.com.au>


In article <1994Apr26.160214.5637_at_oracle.us.oracle.com>, dbmoore_at_us.oracle.com (Dennis Moore) writes:
> In article <2pirep$e6c_at_dockmaster.phantom.com> ynp_at_phantom.com (Youri
> Podchosov) writes:

.
blur before
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>
> What I *can* tell you is that declarative referential integrity is very
> desirable for improving productivity of application developers, reducing
> integrity issues related to application development errors or schema changes
> over time, and for easing the task of end user database query and reporting.
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blur after
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That is what I call the marketing promises and there is no doubt that this feature has enourmous benefits. What you (Dennis) or others, that do not have _real_ world experience, understand that there is a very high price to pay as well. This is to do with the need to create indexes on the FK fields if you do not want performance problems with relating to updating the child tables.

To give you an example, I have a table with 5G of data. To create an index on these FK fields (of which there is hardly any joints to other tables), I will need 4Gbytes of data. Dont forget mirror and I am up for A$25,000!!!

I had to get it off my chest. Oracle does a good job marketing their products but please let us know the downside and disadvantages as well.

ta
tony

-- 
 _____       ________ / ____ |Tony Jambu, Database Administrator
  /_  _        /_ __ /       |Colonial Mutual Invest Mgmt,Aust (ACN004021809)
 /(_)/ )(_/ \_/(///(/_)/_(   |EMAIL: TJambu_at_cmutual.com.au
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Received on Tue May 03 1994 - 08:01:43 CEST

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