基于嵌入式关系的一种Multi-join算法  

A Multi-join Algorithm Based on Nested Relations

作　　者：何伟[1] 洪晓光[1] 王海洋[1] 董继润[1] 

机构地区：[1]山东大学计算机科学系,济南250100

出　　处：《计算机科学》1999年第7期74-76,共3页Computer Science

摘　　要：去掉第一范式“原子属性”的限制条件而得到的关系模式称作嵌入式或扩展的关系模式。嵌入式关系模型已经被数据库理论界接受为一种规范的关系模型,它可以有力地支持存储树型(层次)或图形(网状)数据的系统,比如办公自动化、多媒体系统等许多新的应用领域。试验及分析证明嵌入式关系模型与符合第一范式的关系模型同样严格,换句话说,只要遵守更高的规范形式,删除1NF关系“原子属性”The nested relational model has a better way to represent complex objects than INF relational model. Detailed examination and analysis has proven that the nested relational model is-e-qually robust. The join operation is one of the most expensive operations in nested relational database as well as in INF relational .databases. In this paper we first introduce a form of join operator in the nested relational model- After that,an algorithm for computing multi-join among nested relations on decomposed storage model is proposed.

关 键 词：数据库 嵌入式关系 Multi-join算法 

分 类 号：TP311.13[自动化与计算机技术—计算机软件与理论]