Handling Null Queries with Compound Fuzzy Attributes

We present here a generalized approach for handling null queries that contain compound fuzzy attributes. Null queries are queries that elicit a null answer from the database. Compound fuzzy attributes are ambiguous attributes that are not defined in the original database schema but can be derived from multiple rigid attributes in schema. Compound fuzzy attributes derived from simple numbers were studied by Nomura [11]. In this work, we extend compound fuzzy attributes so that they can be derived from numbers, interval values, scalars, and sets of all these data types. Database management systems that can handle this type of ambiguous attributes in null queries not only can reduce the occurrences of null answers but also provide an improved user-friendly query environment.