Name
Abstract | ||
|---|---|---|
We study optimization of relational queries using materialized views, where views may be regular or restructured. In a restructured view, some data from the base table(s) are represented as metadata-that is, schema information, such as table and attribute names-or vice versa. Using restructured views in query optimization opens up a new spectrum of views that were not previously available, and can result in significant additional savings in query-evaluation costs. These savings can be obtained due to a significantly larger set of views to choose from, and may involve reduced table sizes, elimination of self-joins, clustering produced by restructuring, and horizontal partitioning. In this paper we propose a general query-optimization framework that treats regular and restructured views in a uniform manner and is applicable to SQL select-project-join queries and views without or with aggregation. Within the framework we provide (1) algorithms to determine when a view (regular or restructured) is usable in answering a query and (2) algorithms to rewrite queries using usable views. Semantic information, such as knowledge of the key of a view, can be used to further optimize a rewritten query. Within our general query-optimization framework, we develop techniques for determining the key of a (regular or restructured) view, and show how this information can be used to further optimize a rewritten query. It is straightforward to integrate all our algorithms and techniques into standard query-optimization algorithms. Our extensive experimental results illustrate how using restructured views (in addition to regular views) in query optimization can result in a significant reduction in query-processing costs compared to a system that uses only regular views. |
Year | DOI | Venue |
|---|---|---|
2009 | 10.1016/j.is.2008.10.002 | Inf. Syst. |
Keywords | Field | DocType |
usable view,general query-optimization framework,schema information,select-project-join query,query optimization,regular view,semantic information,base table,table size,standard query-optimization algorithm,materialized views,spectrum | SQL,Query optimization,USable,Data mining,Information retrieval,Computer science,View,Cluster analysis,Versa,Schema (psychology),Materialized view,Database | Journal |
Volume | Issue | ISSN |
34 | 3 | Information Systems |
Citations | PageRank | References |
3 | 0.39 | 25 |
Authors | ||
3 | ||
Name | Order | Citations | PageRank |
|---|---|---|---|
| Dongfeng Chen | 1 | 3 | 0.39 |
| Rada Chirkova | 2 | 450 | 36.53 |
| Fereidoon Sadri | 3 | 846 | 283.70 |