Access Restriction

Author Chang-Sup Park ♦ Myoung Ho Kim ♦ Yoon-Joon Lee
Sponsorship IEEE Comput. Soc. Tech. Committee on Data Eng.
Source IEEE Xplore Digital Library
Content type Text
Publisher Institute of Electrical and Electronics Engineers, Inc. (IEEE)
File Format PDF
Copyright Year ©2001
Language English
Subject Domain (in DDC) Computer science, information & general works ♦ Data processing & computer science
Subject Keyword Data warehouses ♦ Aggregates ♦ Lattices ♦ Usability ♦ Decision support systems ♦ Costs ♦ Materials science and technology ♦ Productivity ♦ Collaborative work
Abstract OLAP queries involve a lot of aggregations on a large amount of data in data warehouses. To process expensive OLAP queries efficiently, we propose a new method for rewriting a given OLAP query using the various kinds of materialized aggregate views which already exist in data warehouses. We first define the normal forms of OLAP queries and materialized views based on the lattice of dimension hierarchies and the semantic information in data warehouses. Conditions for the usability of a materialized view in rewriting a given query are specified by relationships between the components of their normal forms. We present a rewriting algorithm for OLAP queries that effectively utilizes existing materialized views. The proposed algorithm can make use of materialized views having different selection granularities, selection regions and aggregation granularities together, to generate an efficient rewritten query.
Description Author affiliation: Dept. of Electr. Eng. & Comput. Sci., Korea Adv. Inst. of Sci. & Technol., Taejon, South Korea (Chang-Sup Park)
ISBN 0769510019
ISSN 10636382
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Research ♦ Reading
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2001-04-02
Publisher Place Germany
Rights Holder Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Size (in Bytes) 890.55 kB
Page Count 9
Starting Page 515
Ending Page 523

Source: IEEE Xplore Digital Library