Codd's Information Principle
Date: Wed, 28 Oct 2009 19:51:26 GMT
I can't remember where in his papers Codd stated the Information Principle but here's a version of a quote by Date: "The entire information content of a relational database is represented in one and only one way: namely, as attribute values within tuples within relations."
Recently there has been mention of logical connectors being implicit in tuples, eg. Mr. Scott wrote: "Each row of the join represents a conjunction of propositions, one for each operand", ie., what I think is called a compound proposition. I sometimes write similar, as well regarding disjunctions. But usually my purpose is simply to understand the algebra.Received on Wed Oct 28 2009 - 20:51:26 CET