与或图数据库的关系模式规范化算法

Standardized algorithm of relation scheme for hypergraph database

在图论基础上提出了与或图数据库。以与或图为描述工具的一种新的数据库理论 ,它使数据库的理论更加直观 ,算法更加简洁。给出了与或图数据库的定义、规范化理论、无冗余和既约化理论 ,证明了它与关系数据库的等价性 ;然后给出了依赖集存在冗余和既约的必要条件 ,讨论了无损分解在与或图形式下的特性 ,从而形成了与或图数据库关系模式分解的规范化算法。结合实例阐述了与或图数据库比关系数据库更加形象直观 ,便于理解学习 。

The hypergraph database is a new kind of database theory based on graph theory, in which the hypergraph is used as the describing tool instead of a table and makes the theory easier to learn and the algorithm more powerful than that of the relational database. The definition of the hypergraph database, the standardization theory and the theory of non redundancy and predigestion are introduced and the equivalence between the hypergraph database and relational database is investigated. Then, the necessary conditions for testing non redundancy and predigestion and the analysis of loseless decomposability are discussed. Finally, the standardized decomposition algorithm of the relationship scheme for the hypergraph database is summarized. An example demonstrates that the hypergraph database theory is more easily mastered than the relational database theory. The hypergraph database theory provides a foundation for introducing the methods of graph theory and artificial intelligence into database applications.