Redundant elements in attribute values

The existence of redundant elements in attribute values is shown in fuzzy relational databases. The redundancy of an element in an attribute value of a tuple means how much the possible tuple state corresponding to the element is covered by another tuple in a relation. Redundant elements can be created in union, Cartesian product, projection, and selection operations. The harmful effects of redundant elements on query processing are that there are cases of derived relations involving extra tuples being obtained in intersection and selection operations when redundant elements are left in the original relations. The author states that the correct results of query processing cannot be obtained in these operations. Therefore, redundant elements should not be left in relations.<>