Re: object algebra

> It's not clear to me you know what "normalized" means. Can you be
> specific about what normalization rules you are referring to? In
> what way is my schema not normalized?

Normalization: The process of replacing duplicates things with a reference to the original thing.

For example, given "john isa person" and "john obeys army", one observes that the "john" in the second sentence is a duplicate of "john" in the first sentence. Using the means provided by your system, the second sentence should be stored as "->john obeys army".

Another example, given "bob" one observes that the second "b" is a duplicate of the first "b" and therefore should be normalized as "bo->b". I don't want you to normalized this far, even though Ex076 is.

The exact method of normalization and to what extent is practical is dependent on the data model and its implementation.

Sorry, I just realized that I don't want you to explicitly represent the relators "obey", "isa" or "is". They can be implied.

The following might serve as base tables to implement Ex076.  

T_CmdHier
T_God
T_ArmedForce
T_Church
T_Person
T_Dog
T_Computer
T_Age
T_Weight
T_Color

Note: Many of the tables may have just one tuple in order to implement the example. Received on Sat Feb 28 2004 - 06:48:55 CET