摘要
本文探索了dBASEⅢ和Ⅱ的索引文件的结构.每512个字节划分为一块,除了起始块外,各块作为节点构筑成索引树.指明了dBASE索引树的生长规律以及和B^+树的差异.阐述了数值和日期在索引树中的表示形式.给出了二个端点情况的计算公式和求取所有结构参数的算法流程图,以及一般情况下的结构,使得索引文件成为透明文件.最后介绍了检索定位过程,以及增添、修改和删除操作对索引树的影响.
The structure of dBASEIII and dBASE II index file has been researched in
this paper. The index file is divided into blocks, a block has 512 bytes.
Excepting initial block those blocks constitute indexing tree as nodes. The
difference of dBASE indexing tree grom B+ tree, and growing regulation of
indexing tree are pointed. The interior form of number and date are also
expounded. It has been given that formulae or arithmetic method to dete-
rmine all structure parameters of two extremity, and that structure of ge-
neral situation. Finaly, the search and locate process, the influnce of add,
change and delete on indexing tree have been studied.
出处
《苏州丝绸工学院学报》
1990年第2期63-74,共12页
Journal of Suzhou Institute of Silk Textile Technology
关键词
索引文件结构
dBASEⅢ
数据库
index file's structure, dBASE III, dBASE II , database.
