The examples of functional dependencies I've seen boil down to mapping container -> element, and arguments -> result (as in Mult Matrix Vector Vector). They seem to be better expressed with type functions. In database theory, more complex relationships are considered that are not of this form (like a -> b, b -> a). Are there examples of...
Can anyone plz give example how functional dependencies are being implemented in sql. I have read somewhere that functional dependencies can be implemented using assertions. But how these are implemented can anyone give an example for it. Moreover how to implement FD's in Oracle coz, assertions can't be created in oracle. ...
In the attached picture there's a symbol I don't understand. To understand additive functional dependency I need to know what the symbol means. Please advice? It's the symbol where it says: "Suppose that X ⊇ Y and that..." ⊇ = ? Thanks! ...