Multivalued Dependency - Formal Definition

Formal Definition

The formal definition is given as follows.

Let be a relation schema and let and (subsets). The multivalued dependency

(which can be read as multidetermines ) holds on if, in any legal relation, for all pairs of tuples and in such that, there exist tuples and in such that

In more simple words the above condition can be expressed as follows: if we denote by the tuple having values for collectively equal to correspondingly, then whenever the tuples and exist in, the tuples and should also exist in .