【摘要】 数据库的合成和分解在实际应用中是一个很重要的问题,它所对应的数学模型就是信息系统的合成与分解,该文给出了对象合成信息系统、属性合成信息系统、对象子信息系统及属性子信息系统的定义,讨论了合成信息系统、子信息系统与原信息系统等属性特征之间的关系。更多还原

【Abstract】 The composition and decomposition of the data base is an important problem in practice application,and its mathematic model is the composition and decomposition of the information systems.By giving definition of object composed information systems,attribute composed information systems,sub-object information systems and sub-attribute information systems,this paper discusses the attribute character relationships between the combined information systems and the original information systems,sub-information systems and the original information systems, respectively.更多还原