G. N. Paulley, Per-Åke Larson  Home/Search
Context Related
| microsoft.com/users/pala...icde94_pl.ps Cached: PS.gz PS PDF This document uses CoBlitz to cache paper downloads. If your firewall is blocking outgoing connections to port 3125, you can use these links to download local copies.
Image Update HelpPS.gz PS PDF From: microsoft.com/~pal...publications (more) (Enter author homepages) |
Rate this article:      (best)Comment on this article |
Abstract: Consider an sql query that specifies duplicate elimination via a Distinct clause. Because duplicate elimination often requires an expensive sort of the query result, it is often worthwhile to identify unnecessary Distinct clauses and avoid the sort altogether. We prove a necessary and sufficient condition for deciding if a query requires duplicate elimination. The condition exploits knowledge about keys, table constraints, and query predicates. Because the condition cannot always be tested... (Update)
Context of citations to this paper: More
...such as predicate pushdown [Ull88] and pullup [HS93, Hel94] early and late aggregation (c.f. YL94] duplicate elimination removal [PL94] and DISTINCT pullup and pushdown, should be applied to coalescing. Effective cost formulas for coalescing are needed. Concerning...
...not in conflict with our definition, if we keep in mind, that we regard constraints as constraints for queries. Paulley and Larson [Paulley and Larson, 1994] present an approach to remove unnecessary distinct keywords. The differences between their approach and ours is, we...
Cited by: More
Using Horizontal-Vertical Decompositions to Improve .. - Giannella.. (Correct)
Exploiting Constraint-Like Data Characterizations in Query.. - Godfrey, Gryz (2001) (Correct)
Deciding Distinctness of Query Results by Discovered Constraints - Bell (Correct)
Active bibliography (related documents): More All
0.7: Performing Group-By before Join - Yan (1994) (Correct)
0.4: Including Group-By in Query Optimization - Chaudhuri (1994) (Correct)
0.2: Extensions to the Relational Data Model - Scholl (1992) (Correct)
Similar documents based on text: More All
0.0: Exact Positioning of Data Approach to Memory Mapped Persistent.. - Goel (1996) (Correct)
0.0: Authenticated Key Exchange Secure Against Dictionary Attacks - Bellare, Pointcheval.. (2000) (Correct)
0.0: Clustering of Pre-Main Sequence Stars in the Orion, Ophiuchus.. - Nakajima (1997) (Correct)
Related documents from co-citation: More All
3: Logic-based approach to semantic query optimization (context) - Chakravarthy, Grant et al. - 1990
2: Efficient discovery of functional dependencies and armstrong relations (context) - Lopes, Petit et al. - 2000
2: Efficient Discovery of Functional and Approximate Dependencies Using Partitions - Huhtala, Karkkainen et al. - 1998
BibTeX entry: (Update)
G. N. Paulley and P.-A. Larson. Exploiting Uniqueness in Query Optimization. In Proceedings of the International Conference on Data Engineering, pages 68--79, February 1994. http://citeseer.ist.psu.edu/paulley94exploiting.html More
@inproceedings{ paulley94exploiting,
author = "G. N. Paulley and Per-Ake Larson",
title = "Exploiting Uniqueness in Query Optimization",
booktitle = "{ICDE}",
pages = "68-79",
year = "1994",
url = "citeseer.ist.psu.edu/paulley94exploiting.html" }
Citations (may not include all citations):981 Principles of Database and Knowledge-Base Systems (context) - Ullman - 1988
434 An Introduction to Database Systems (context) - Date - 1990
200 The Theory of Relational Databases (context) - Maier - 1983
170 Deriving production rules for incremental view maintenance - Ceri, Widom - 1991
74 On optimizing an sql-like nested query (context) - Kim - 1982
59 Of nests and trees: A unified approach to processing queries.. (context) - Dayal - 1987
44 Performing group by before join - Yan, Larson - 1994
39 rule based query rewrite optimization in starburst (context) - Pirahesh, Hellerstein et al. - 1992
34 Improved unnesting algorithms for join aggregate sql queries (context) - Muralikrishna - 1992
32 Query Optimization by Semantic Reasoning (context) - King - 1984
31 Translating sql into relational algebra: Optimization (context) - Ceri, Gottlob - 1985
31 Decomposition---A strategy for query processing (context) - Wong, Youssefi - 1976
28 Information Technology---Database Language sql 2 Draft Repor.. (context) - Organization - 1990
10 High-performance implementation techniques for next-generati.. (context) - Shekita - 1991
10 Calculating constraints on relational expressions (context) - Klug - 1980
7 On semantic reefs and efficient processing of correlation qu.. (context) - Kiessling - 1985
6 Formal semantics of sql queries (context) - Negri, Pelagatti et al. - 1991
4 Translating and optimizing sql queries having aggregates (context) - von Bultzingsloewen - 1987
3 Optimization of nested queries revisited (context) - Ganski, Wong - 1987
1 Semantic query optimization using generalized functional dep.. (context) - okia, obert - 1989
1 esa Version 3 General Information (context) - Corporation - 1989
1 Relational Access to ims Databases: Gateway Structure and Jo (context) - Larson - 1990
Documents on the same site (http://www.research.microsoft.com/~palarson/publications.htm): More
Efficiently Updating Materialized Views - Blakeley, Larson, Tompa (1986) (Correct)
Text / Relational Database Management Systems: Harmonizing SQL .. - Blake Consens (1994) (Correct)
Managing Global Information in the CORDS Multidatabase System - Bauer, Coburn, Larson, al. (1994) (Correct)
Online articles have much greater impact More about CiteSeer.IST Add search form to your site Submit documents Feedback
CiteSeer.IST - Copyright Penn State and NEC