基于层次位图连接索引的数据仓库查询优化

Query Optimization of Data Warehouse Based on Hierarchical Bitmap Join Index

在数据仓库的联机分析处理的查询处理中,经常会涉及到大量数据的复杂即席查询。用户通过提交联机分析处理查询对数据进行分析和决策支持,这通常需要较快的查询响应速度。因此,提高联机分析处理的查询性能就成为了数据仓库领域的关键问题。为了提高数据仓库的查询性能,结合维表层次结构的特点,提出一种将分段位图索引和位图连接索引有效结合的方法。实验证明,该方法节省了位图索引的储存空间,减少了I/O开销,有效地提高了数据仓库的查询效率。

The query processing of the OLAP of the data warehouse usually involves complex query on a large number of datum. Users analyze the data and achieve decision support by submitting OLTP query, which usually needs a fast response speed. Therefore, improving the OLAP query performance becomes the key issue in the field of data warehouse. In order to improve the query performance, an effective method to combine with sub-bitmap indexes and bitmap join indexes is composed according to the characteristics of the hierarchy in the dimension table. Experimental results show that the method reduced the storage space of the bitmap indexes and I/O Cost, and improves the queries efficiency of data warehouse.