Article in Proceedings INPROC-2003-04

BibliographyKraft, Tobias; Schwarz, Holger; Rantzau, Ralf; Mitschang, Bernhard: Coarse-Grained Optimization: Techniques for Rewriting SQL Statement Sequences.
In: Proceedings of 29th International Conference on Very Large Data Bases (VLDB 2003), Berlin, September 9-12, 2003.
University of Stuttgart, Faculty of Computer Science.
pp. 488-499, english.
Morgan Kaufmann, September 2003.
ISBN: 0-12-722442-4.
Article in Proceedings (Conference Paper).
CR-SchemaH.2.4 (Database Management Systems)
KeywordsSQL; Query Optimization; OLAP
Abstract

Relational OLAP tools and other database applications generate sequences of SQL statements that are sent to the database server as result of a single information request provided by a user. Unfortunately, these sequences cannot be processed efficiently by current database systems because they typically optimize and process each statement in isolation. We propose a practical approach for this optimization problem, called ``coarse-grained optimization,'' complementing the conventional query optimization phase. This new approach exploits the fact that statements of a sequence are correlated since they belong to the same information request. A lightweight heuristic optimizer modifies a given statement sequence using a small set of rewrite rules. Since the optimizer is part of a separate system layer, it is independent of but can be tuned to a specific underlying database system. We discuss implementation details and demonstrate that our approach leads to significant performance improvements.

Department(s)University of Stuttgart, Institute of Parallel and Distributed High-Performance Systems, Applications of Parallel and Distributed Systems
Project(s)ORBIT
Entry dateJune 30, 2003
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