DATALOG与关系代数

ON DATALOG AND RELATIONAL ALGEBRA

本文旨在通过描述DATALOG和关系代数的概念,以及DATALOG与关系代数的区别,经过从关系代数到逻辑规则和从逻辑到关系的论述,并比较DATALOG和关系代数,说明DATALOG是一种基于逻辑的数据模型,是PROLOG语言的数据库版本,关系代数是过程化的语言,关系代数表达式与安全、非递归、带有非操作的DATALOG程序的表达能力是相同的。

In the first place of this paper, the concepts of DATALOG and relational algebra, as well as the difference between the two are described.The relational algebra and the logical rule from logic to relation are discussed. By comparison, it illuminates that DATALOG is a data model based on logic,and is also a database version of PROLOG language. Relational algebra is a process language, whose expression is the same with the DATALOG program on security,nonrecursion and having blame operation.