Re: Nearest Common Ancestor Report (XDb1's $1000 Challenge)

> why is Codd's first normal form an unnaccaptable solution to the problem?

Because 1NF and the remaining xNF are only limited forms of normalization whose ultimate goal is to remove redundant data. In RM Sol#1 and #2, some redundancies are: redundant tables (ie T_ClassHierarchy) to store hierarchies, redundant method of storing attributes (ie T_thing.name vs T_attributes), and redundant values (ie brown) in T_thing and T_attribute_value.

See C. J. Date's "An Intro to Db Systems", 6th Ed, Chapter 10 Further Normalization, pg 291: "By now the reader might well be wondering whether there is any end to this progression and whether there might be a 6NF, a 7NF, and so on ad infintum. Although this is a good question to ask, we are obviously not in a position to give it any detailed consideration as yet. We content ourselves with the rather equivocal statement that there are indeed additional normal forms not shown in Fig 10.2, but that 5NF is actually the 'final' form in a special (but important) sense."

> You did say "normalized" without any qualifiations didn't you?

Yes because normalization in the context of dbs mean to eliminate redundant data.

> Sorry, you lose.

If losing means, understanding normalization as eliminating redundant data, then yes I have lost. If winning means, seeing 1NF as normalization, then yes you have won. Received on Wed Jun 09 2004 - 18:13:09 CEST