关键词: 粗糙关系数据库（RRDB）, 等价关系, 分解, 位模式, 粗糙熵

Abstract: The fundamental concept of rough relational database is introduced in this paper, some prime mathematics theories including equivalence relation, decomposition theory, bit pattern, rough entropy and rough set used in the study of rough relational database are investigated in detail, moreover some conclusions about these theories related on rough relational database are obtained, and their applications are discussed too. 

Key words: Rough Relational Database（RRDB）, equivalence relation, decomposition, bit pattern, rough entropy