【摘要】 本文首先分析了在 NDBMS(Network Data Base Management System,网络数据库管理系统 )中查询优化的特点、策略和目标 ,提出了查询优化的数学模型。在对几种联接方案分析比较的基础上 ,提出了一种基于最佳联接法的查询优化算法 ,详细讨论了该算法的设计思想和实施关键。该技术在很大程度上提升了现有 NDBMS的功能 ,从而对网络数据库技术的应用和推广产生积极的作用更多还原

【Abstract】 This paper analyzes the characteristics,strategies and aims of query optimization in the Network Data Base Management System,and then advances a mathematic model of technique of query optimization.After analyzing and comparing several join schemes,a query optimization algorithm based on optimal join idea is advanced,and the design idea and implemental key technique of this kind of algorithm are discussed in detail.We believe that this technology can advance the functions of current NDBMS,and take active effect for applying and popularizing the network database technology.更多还原