Re: How to find Brothers and Sisters?

>> Joe wouldn't know RM1 if it bit him on the ass. Codd's original specification of 1NF appeared in his 1969 and 1970 papers and had absolutely nothing to do with the 12 rules some vendor paid him to publish. <<

You are thinking of his OLAP paper, which Arbor software commissioned. That paper was supposedly written by someone else on his staff and Dr. Codd put his name on it. That "cut & paste" of mine was taken from Chris Date's description of Codd's final rules for Version 1.0 of the RM.

The NULL for "attribute exists, value unknown" and "attribute missing, so value is impossible" did not come along until RM Version 2.0.

In his book DATABASE IN DEPTH, Date lists:

RM1: The 1970 CACM paper
RM2: 1981 Turing Award Paper
RM3: Codd's 12 rules in 1985 which locked down Version 1.0
RM4: The Version 2.0 book in 1990

Date then asserts that his Third Manifesto is The Only One and True RM :)

>> Joe is living proof that, if one cannot dazzle with brilliance, one can always baffle with bullshit instead.<<

Thank you for your logical argument and documentation. Oh wait; there was only an ad hominem attack.

>> Judge: "Why didn't you pay the plaintiff?"
 Defendant: "We did pay the plaintiff."
 Judge: "Really? How much did you pay the plaintiff?"  Defendant: "We don't know, but we know we paid him." <<

Knowing existence without particulars is a common situation. To carry on with your courtroom example:

 Judge: "How do you know this man was murdered?"  Detective: "People do not shoot themselves 10 times in the back of the head and dismember their own corpse."
 Judge: "Really? Who murdered him?"
 Detective: "We do not know yet."
 Bob: "If you don't know who did it, then this cannot be a murder! You must have absolute knowledge!"

Yu might want to look at the problem of missing data in statistics and Data Theory. Years ago SPARC lists well over a dozen kinds of missing data in data and their computerized representations. Then along came fuzzy math and logic (the CSI guy who can tell you that the prep was left handed and about 5'10" tall, but still not give you his name), various multi-valued logics and a host of other things. SQL and its NULLs are very vanilla. Received on Tue Jan 16 2007 - 08:23:31 CET