Definition
The query execution engine operates on an execution plan produced during query processing which typically is a physical operator graph whose edges specify the dataflow among the operators. There are two basic alternatives for evaluating the execution plan: materialization and pipelining. With materialized evaluation, the results of each operator are created (materialized) and stored in disk and then used as input for the evaluation of the next operator. With pipelining, the results of an operator are passed along as input to the next operator, before the first operator completes its execution. In general, pipelining improves the efficiency of query evaluation by reducing the number of temporary files that are produced.
Key Points
The output of query optimization is an execution plan or operator tree. The execution plan can be thought of as a dataflow graph where the nodes correspond to the physical operators and the edges represent the data flow among these physical...
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsRecommended Reading
Graefe G. Query evaluation techniques for large databases. ACM Comput Surv. 1993;25(2):73–170.
Silberschatz A, Korth HF, Sudarshan S. Database system concepts. 5th ed. New York: McGraw Hill; 2005.
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). Pipelining. 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_872
Download citation
DOI: https://doi.org/10.1007/978-1-4614-8265-9_872
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