Eager Aggregation and Lazy Aggregation.

Weipeng P. Yan, Per-Åke Larson: Eager Aggregation and Lazy Aggregation. VLDB 1995: 345-357
  author    = {Weipeng P. Yan and
               Per-{\AA}ke Larson},
  editor    = {Umeshwar Dayal and
               Peter M. D. Gray and
               Shojiro Nishio},
  title     = {Eager Aggregation and Lazy Aggregation},
  booktitle = {VLDB'95, Proceedings of 21th International Conference on Very
               Large Data Bases, September 11-15, 1995, Zurich, Switzerland},
  publisher = {Morgan Kaufmann},
  year      = {1995},
  isbn      = {1-55860-379-4},
  pages     = {345-357},
  ee        = {db/conf/vldb/YanL95.html},
  crossref  = {DBLP:conf/vldb/95},
  bibsource = {DBLP,}


Efficient processing of aggregation queries is essential for decision support applications. This paper describes a class of query transformations, called eager aggregation and lazy aggregation, that allows a query optimizer tomove group-by operations up and down the query tree. Eager aggregation partially pushes a group-by past a join. After a group-by is partially pushed down, we still need to perform the original group-by in the upper query block. Eager aggregation reduces the number of input rows to the join and thus may result in a better overall plan. The reverse transformation, lazy aggregation, pulls a group-by above a join and combines two group-by operations into one. This transformation is typically of interest when an aggregation query references a grouped view (a view containing a group-by). Experimental results show that the technique is very beneficial for queries in the TPC-D benchmark.

Copyright © 1995 by the VLDB Endowment. Permission to copy without fee all or part of this material is granted provided that the copies are not made or distributed for direct commercial advantage, the VLDB copyright notice and the title of the publication and its date appear, and notice is given that copying is by the permission of the Very Large Data Base Endowment. To copy otherwise, or to republish, requires a fee and/or special permission from the Endowment.

Online Paper

ACM SIGMOD Anthology

CDROM Version: Load the CDROM "Volume 1 Issue 5, VLDB '89-'97" and ... DVD Version: Load ACM SIGMOD Anthology DVD 1" and ... BibTeX

Printed Edition

Umeshwar Dayal, Peter M. D. Gray, Shojiro Nishio (Eds.): VLDB'95, Proceedings of 21th International Conference on Very Large Data Bases, September 11-15, 1995, Zurich, Switzerland. Morgan Kaufmann 1995, ISBN 1-55860-379-4
Contents BibTeX


Surajit Chaudhuri, Kyuseok Shim: Including Group-By in Query Optimization. VLDB 1994: 354-366 BibTeX
Ashish Gupta, Venky Harinarayan, Dallan Quass: Aggregate-Query Processing in Data Warehousing Environments. VLDB 1995: 358-369 BibTeX
Guy M. Lohman: Grammar-like Functional Rules for Representing Query Optimization Alternatives. SIGMOD Conference 1988: 18-27 BibTeX
Hamid Pirahesh, Joseph M. Hellerstein, Waqar Hasan: Extensible/Rule Based Query Rewrite Optimization in Starburst. SIGMOD Conference 1992: 39-48 BibTeX
Weipeng P. Yan, Per-Åke Larson: Performing Group-By before Join. ICDE 1994: 89-100 BibTeX

Referenced by

  1. Wen-Chi Hou: A Framework for Statistical Data Mining with Summary Tables. SSDBM 1999: 14-23
  2. Yihong Zhao, Prasad Deshpande, Jeffrey F. Naughton, Amit Shukla: Simultaneous Optimization and Evaluation of Multiple Dimensional Queries. SIGMOD Conference 1998: 271-282
  3. Jun Rao, Kenneth A. Ross: Reusing Invariants: A New Strategy for Correlated Queries. SIGMOD Conference 1998: 37-48
  4. Michael Jaedicke, Bernhard Mitschang: On Parallel Processing of Aggregate and Scalar Functions in Object-Relational DBMS. SIGMOD Conference 1998: 379-389
  5. Surajit Chaudhuri: An Overview of Query Optimization in Relational Systems. PODS 1998: 34-43
  6. Jae-young Chang, Sang-goo Lee: Query Reformulation Using Materialized Views in Data Warehousing Environment. DOLAP 1998: 54-59
  7. Venky Harinarayan: Issues in Interactive Aggregation. IEEE Data Eng. Bull. 20(1): 12-18(1997)
  8. Inderpal Singh Mumick, Dallan Quass, Barinderpal Singh Mumick: Maintenance of Data Cubes and Summary Tables in a Warehouse. SIGMOD Conference 1997: 100-111
  9. Ching-Tien Ho, Rakesh Agrawal, Nimrod Megiddo, Ramakrishnan Srikant: Range Queries in OLAP Data Cubes. SIGMOD Conference 1997: 73-88
  10. Joseph M. Hellerstein, Peter J. Haas, Helen J. Wang: Online Aggregation. SIGMOD Conference 1997: 171-182
  11. Ching-Tien Ho, Jehoshua Bruck, Rakesh Agrawal: Partial-Sum Queries in Data Cubes Using Covering Codes. PODS 1997: 228-237
  12. Hamid Pirahesh, T. Y. Cliff Leung, Waqar Hasan: A Rule Engine for Query Transformation in Starburst and IBM DB2 C/S DBMS. ICDE 1997: 391-400
  13. Alexandra Poulovassilis, Carol Small: Formal Foundations for Optimising Aggregation Functions in Database Programming Languages. DBPL 1997: 299-318
  14. Wolfgang Lehner, Thomas Ruf: A Redundancy-Based Optimization Approach for Aggregation in Multidimensional Scientific and Atatistical Databases. DASFAA 1997: 253-262
  15. Ming-Syan Chen, Jiawei Han, Philip S. Yu: Data Mining: An Overview from a Database Perspective. IEEE Trans. Knowl. Data Eng. 8(6): 866-883(1996)
  16. Damianos Chatziantoniou, Kenneth A. Ross: Querying Multiple Features of Groups in Relational Databases. VLDB 1996: 295-306
  17. Alon Y. Levy, Inderpal Singh Mumick: Reasoning with Aggregation Constraints. EDBT 1996: 514-534
  18. Surajit Chaudhuri, Kyuseok Shim: Optimizing Queries with Aggregate Views. EDBT 1996: 167-182
  19. Surajit Chaudhuri, Kyuseok Shim: An Overview of Cost-based Optimization of Queries with Aggregates. IEEE Data Eng. Bull. 18(3): 3-9(1995)
ACM SIGMOD Anthology - DBLP: [Home | Search: Author, Title | Conferences | Journals]
VLDB Proceedings: Copyright © by VLDB Endowment,
ACM SIGMOD Anthology: Copyright © by ACM (, Corrections:
DBLP: Copyright © by Michael Ley (, last change: Sat May 16 23:46:05 2009