一种基于虚拟数据仓库的查询优化方法

A Query Optimization Method Based on Virtual Data Warehouse

跨地区企业集团如何从分布在各地数据仓库的数据中获取信息以帮助他们决策是数据仓库研究的一个重要问题。本文提出了一种虚拟数据仓库三层模型及其查询优化方法,引入了虚拟元数据、查询快表等概念,通过查询快表可以快速得到查询方案,通过虚拟元数据与各结点元数据的映射,可形成查询方案,从而获得查询结果。分析表明,该方法能够有效地提高查询效率。

For trans - regional enterprises, it is an important researchful problem to get information from data warehouses of different regions for decision - making. In this paper, the author proposes a query optimization algorithm based on virtual data warehouse. In addition, the author introduces the concept of metadata and quick query table. Through quick query table, you can get query scheme quickly. And then through mapping between quick query table and each metadata, you can form query scheme and finally get query results. Analysis data illustrate query efficiency can get improved by using this method.