【摘要】 当前B~+树索引结构常采用"溢出页"处理重复出现的键值,易于实现,但存在严重的空间浪费。该文通过改进索引结构的定义,使B~+树能够显式支持重复键值,并给出相应算法。实验证明,采用该方法的P+树能有效减少索引文件的大小,使B~+树满足更多数据库索引的需求。更多还原

【Abstract】 Overflow page is commonly used to deal with the duplicate keys of a B~+ tree index,although it is easy to implement,it introduces great space waste.This paper adopts an alternative approach to make the B~+ tree explicitly support the duplicate keys by revising the index structure,and provides the basic algorithms to implement the idea.Experiment indicates that the revised B~+ tree can significantly reduce the size of the index file, which broadens the application area of B~+ tree.更多还原