摘要： 检索性能的优劣在数据仓库应用中是至关重要的，位图索引在性能优化中起关键作用之一， 并且它和传统的B树索引是不同的。通过实例描述了位图索引的构成原理，即：位图索引是由一系列有序的位向量组成；详细阐述了位图索引的特性（包括优点和缺点）以及其使用条件。最后文章结论指出合理地使用位图索引可以极大地改善大型系统的检索效率和减少系统资源。 全文查看链接 　　Bitmap indexes have been proposed and supported by some commercial DBMS. These data structures are particularly well adapted to DW environment. In this paper we first describe the principle of bitmap indexes in Section 1. In Section 2 we present the SQL statements for creation of bitmap indexes. We study the features of bitmap indexes in Section 3 and usage conditions of bitmap indexes in Section 4. We conclude the paper and present the significance of bitmap indexes in Section 5. 全文查看链接 　　A query on bitmap indexes is eventually converted to a Boolean logic operation on the bit arrays， which can efficiently merge the indexes that correspond to the conditions in a WHERE clause. The rows that don’t satisfy the conditions are filtered out before the base table itself is accessed. This extremely improves query performance through avoiding full table scan.[7] 全文查看链接