NDLI: An optimization of disjunctive queries: union-pushdown

Content Provider	IEEE Xplore Digital Library
Author	Jae-Young Chang Sang-Goo Lee
Copyright Year	1997
Description	Author affiliation: Dept. of Comput. Sci., Seoul Nat. Univ., South Korea (Jae-Young Chang)
Abstract	Most previous works on query optimization techniques deal with conjunctive queries only because the queries with disjunctive predicates are complex to optimize. Hence, for disjunctive queries, query optimizers based on these techniques generate plans using rather simple methods such as CNF- and DNF-based optimization. However, the plans generated by these methods perform extremely poorly for certain types of queries. The authors propose new query optimization method, union-pushdown, for disjunctive queries. This method is composed of four phases, and each phase utilizes some advantageous techniques of CNF- and DNF-based methods. They analyze the performance of the union-pushdown plan against those of conventional plans and show that union-pushdown can be applied to various disjunctive query types without performance degradation.
Starting Page	356
Ending Page	361
File Size	584164
Page Count	6
File Format	PDF
ISBN	0818681055
ISSN	07303157
DOI	10.1109/CMPSAC.1997.624993
Language	English
Publisher	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Publisher Date	1997-08-13
Publisher Place	USA
Access Restriction	Subscribed
Rights Holder	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Subject Keyword	Optimization methods Query processing Computer science Performance analysis Degradation Costs Data engineering Sections Proposals
Content Type	Text
Resource Type	Article
Subject	Computer Science Applications Software

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in