An Overview of Rough Set Theory from the Point of View of Relational Databases

Both relational database theory (RDB) and rough set theory (RS) are formal theories derived from the study of tables. However, they were based on different philosophies and went on to different directions. RDB assumes semantics of data is known and focuses on organizing data through its semantics. RS, in this table format, assumes data semantics is defined by the given data and focuses on discovering patterns, rules and data semantics through those available data a data mining theory. In this paper, fundamental notions of two theories are compared and summarized. Further, RS can also take abstract format. In this format it can be used to analyze imprecise, uncertain or incomplete information in data. It is a new set theory complimentary to fuzzy set theory. In this paper, this aspect is only lightly touched.