Lossless Join Decomposition for Extended Possibility-Based Fuzzy Relational Databases

Algorithm 1

ALJD Algorithm.

Inputs R and F, where R is a relation and F is the set of FFDs exists in .

Step  1. Let and be the set of all that are not trivial.

Step  2. For a : ~> in , Let be the relation chosen from such that both and are in .

Step  3. If X is not a key attribute in , do followings:

   (1) decompose into and , such that and

   (2) let (remove from )

   (3) let .

Step  4. Go to Step  2 if is not empty.

Output is , the set of relations decomposed from .

Note: represents the list of all attributes in other than X.