Re: Proposal: 6NF

Imaginary numbers are not values belonging to domain of reals. Nevertherless they are values.

NULLS are NOT values.

NULLS is SQL's poor way of handling missing data by making arbirtrary assumptions about what *should be there*. There is a number of possible values greater than one for each NULL value stored in a database and therefore predicate can not be validated (therefore you have no facts in your database). In a way, one could conceive NULL's as a occurrence of some random function in a limited set of possibilities but certainy not as a value. To make your database state facts about reallity under the form of predicate you use values that belong to well defined domain of values that are derived from one another.

NULL is the carpet under which you hide the dirt of missing data instead of throwing it to the trash. It is practical YES. But it has the drawback of making your count results false if you, your team and all people working on the db during the system life cycle, do not put additional IS NULL/IS NOT NULL conditions in all procedures selecting values from tables allowing NULLS. Adding such conditions kills performance at overall server level. So. Result FALSE/ Performance (Response Time/Concurrency) Down.. Do you still believe that NULLS are a good idea? Received on Sun Oct 01 2006 - 07:59:12 CDT