Query Processing in Database Systems

W. Kim, D. S. Reiner et Don Batory

ISBN 10: 3540138315 / ISBN 13: 9783540138310

Verlag: Springer-Verlag Berlin and Heidelberg GmbH & Co. K, 1985

Beschreibung

Ancien livre de bibliothèque. Edition 1985. Ammareal reverse jusqu'à 15% du prix net de cet article à des organisations caritatives. ENGLISH DESCRIPTION Book Condition: Used, Very good. Former library book. Edition 1985. Ammareal gives back up to 15% of this item's net price to charity organizations.

Bestandsnummer des Verkäufers E-553-988

Bibliografische Details

• Titel: Query Processing in Database Systems
• Verlag: Springer-Verlag Berlin and Heidelberg GmbH & Co. K
• Erscheinungsjahr: 1985
• Sprache: Englisch
• ISBN-10: 3540138315
• ISBN-13: 9783540138310
• Einband: Hardcover
• Zustand: Très bon

Über diesen Titel

Inhaltsangabe

This book is an anthology of the results of research and development in database query processing during the past decade. The relational model of data provided tremendous impetus for research into query processing. Since a relational query does not specify access paths to the stored data, the database management system (DBMS) must provide an intelligent query-processing subsystem which will evaluate a number of potentially efficient strategies for processing the query and select the one that optimizes a given performance measure. The degree of sophistication of this subsystem, often called the optimizer, critically affects the performance of the DBMS. Research into query processing thus started has taken off in several directions during the past decade. The emergence of research into distributed databases has enormously complicated the tasks of the optimizer. In a distributed environment, the database may be partitioned into horizontal or vertical fragments of relations. Replicas of the fragments may be stored in different sites of a network and even migrate to other sites. The measure of performance of a query in a distributed system must include the communication cost between sites. To minimize communication costs for-queries involving multiple relations across multiple sites, optimizers may also have to consider semi-join techniques.