On Thu, Jun 08, 2006 at 05:21:07AM -0700, dananrg@xxxxxxxxx wrote: > I'm reading, and enjoying immensely, Fabial Pascal's book "Practical > Issues in Database Management." Be aware that Pascal, along with Date and Darwen, are...how do I put this gently...cranks. They've been getting more strident and irrational as the decades go by. Pascal, Date, and Darwen have been alleging for years, with increasing shrillness, that DBMSs should be based on set theory and 2-value logic. I say "alleging" because they have not backed up this idea with any actual software that others could test. SQL DBMSs are based on bag theory[1] and 3-value logic[2]. Until they come up with a testable system, or Hell freezes over, whichever comes first, Pascal's book will make a good companion on your shelf to books on Phlogiston[3] theory, or a decent doorstop, whichever you prefer. Cheers, D [1] Basically set theory with repetition of elements allowed. This in turn makes aggregates easy and natural to implement. [2] A boolean value can take the values true, false and unknown. [3] http://en.wikipedia.org/wiki/Phlogiston -- David Fetter <david@xxxxxxxxxx> http://fetter.org/ phone: +1 415 235 3778 AIM: dfetter666 Skype: davidfetter Remember to vote!
