Synonyms
Query transformations
Definition
Query rewriting is one of the initial phases of query processing. After the original query is parsed and translated into an internal representation, query rewrite transforms it to an equivalent one by carrying out a number of optimizations that are independent of the physical state of the system. Typical transformations include un-nesting of subqueries, views expansions, elimination of redundant joins and predicates and various other simplifications.
Key Points
Query rewriting is one of the phases of query processing. It refers to the application of a number of transformations to the original query in order to produce an equivalent optimized one. Such transformations do not depend on the physical state of the system (such as the size of the relations, the system workload, etc). They are usually based on well-defined rules that specify how to transform a query expression into a logically equivalent one.
The goal of query rewriting is threefold:...
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Recommended Reading
Hellerstein JM, Stonebraker M, Hamilton J. Architecture of a database system. Found Trends Databases. 2007;1(2):141–259.
Jarke M, Koch J. Query optimization in database systems. ACM Comput Surv. 1984;16(2):111–52.
Pirahesh H, Hellerstein JM, Hasan W. Extensible/rule based query rewrite optimization in starburst. In: Proceedings of the ACM SIGMOD International Conference on Management of Data; 1992. p. 39–48.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Section Editor information
Rights and permissions
Copyright information
© 2018 Springer Science+Business Media, LLC, part of Springer Nature
About this entry
Cite this entry
Pitoura, E. (2018). Query Rewriting. In: Liu, L., Özsu, M.T. (eds) Encyclopedia of Database Systems. Springer, New York, NY. https://doi.org/10.1007/978-1-4614-8265-9_863
Download citation
DOI: https://doi.org/10.1007/978-1-4614-8265-9_863
Published:
Publisher Name: Springer, New York, NY
Print ISBN: 978-1-4614-8266-6
Online ISBN: 978-1-4614-8265-9
eBook Packages: Computer ScienceReference Module Computer Science and Engineering