Re: Failure Modes and Ranges of Operation

From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Sat, 03 Feb 2007 15:35:59 GMT
Message-ID: <zZ1xh.1883$R71.27336_at_ursa-nb00s0.nbnet.nb.ca>


Bob Badour wrote:

> Failure mode analysis is very important in engineering. I wonder whether
> it has any supporting theory? Certainly, one can think of general
> principles. Likewise, beyond statistical analysis and empirical
> measurement, does any theory exist regarding ranges of operation?
>
> Any thoughts?

It occurs to me that naive and ill-considered solutions actually discourage proper failure mode analysis. SQL and NULL demonstrate this clearly.

It seems the SQL folks used NULL as a crutch to avoid thinking about important issues. For example, consider all the places where SQL returns NULL when we know that is just plain wrong and where a perfectly valid, correct answer exists: e.g. summation over zero elements.

It strikes me the SQL folks probably mistook summation over zero elements for a failure condition and had fallen into the habit of substituting NULL for thought when it comes to failure modes. Regardless what some may believe, no rational justification exists to equate divison by zero with NULL, and yet SQL does it. Received on Sat Feb 03 2007 - 16:35:59 CET

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