Re: Implementation of boolean types.

From: Marshall Spight <>
Date: 19 Jul 2005 13:44:48 -0700
Message-ID: <>

dawn wrote:
> Marshall Spight wrote:
> Yup! I've worked with tools that have a null value (yes "value") that
> models the null set and I've worked with SQL and it is so much easier
> and more intuitive to work with a 2VL and null value = empty set model.
> Design, development, trouble-shooting, and maintenance are all
> significantly easier with this model.
> This is one of several features where those attempting to implement
> relational theory took what was working in databases in the 70's (such
> as 2VL) and mucked it up, contributing to greater cost of ownership for
> data-centric applications.

Hmmm. I detect that perhaps you are trying to identify this issue as being somehow a consequence of RM? If so I would not agree; the issues are independent.

> Taking just this one issue, I suspect the
> path to getting the industry from here to there is via XML/XQuery,
> perhaps? However, I did read that SQLServer has an option of switching
> from 3VL to 2VL.

I don't think I'd agree with this either. SQL needs to be replaced, not fixed, and the XML-family of technologies are fundamentally flawed. I don't think any "data management" system that doesn't have a type system or a schema in version one is going to go anywhere. You can't retrofit these things; they have to be designed in from the start. (Yes, I know XML now has various ways to specify schema, with at least DTD and XMLSchema. [Does anyone anywhere think they are good?] Reminds me of the old saw about a man with two watches.)

Anyway, XML doesn't address data management; it's a document management system.

Marshall Received on Tue Jul 19 2005 - 22:44:48 CEST

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