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A Study of moving Selection Down, and Top-Down and Bottom-Up Evaluation Strategies for Logical Queries

Li, Tian-Zhu and Korfhage, Robert R (1990) A Study of moving Selection Down, and Top-Down and Bottom-Up Evaluation Strategies for Logical Queries. Technical Report. School of Library and Information Science, University of Pittsburgh, Pittsburgh, PA.

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Abstract

Static optimization of logical queries, substantially, is to push selection as far as possible in evaluating the relations of the queries. This paper shows that using Ullman's RGG (Rule/Goal Graph), static optimization for all the situations, non-recursive, recursive, mutually recursive, with some functions included, can be processed intuitively. several possible models of pushing selections down are presented. It is easy to understand and to see how, and how far the selections can be pushed down. Based on this, a recommendation about which of Top-Down and Bottom-Up evaluation strategies should be adopted is presented. This approach is better than other static optimization approach.


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Details

Item Type: Monograph (Technical Report)
Status: Published
Creators/Authors:
CreatorsEmailPitt UsernameORCID
Li, Tian-Zhu
Korfhage, Robert Rrrk8@pitt.eduRRK8
Monograph Type: Technical Report
Date: June 1990
Date Type: Publication
Access Restriction: No restriction; Release the ETD for access worldwide immediately.
Publisher: School of Library and Information Science, University of Pittsburgh
Place of Publication: Pittsburgh, PA
Institution: University of Pittsburgh
Department: School of Library and Information Science
Schools and Programs: School of Information Sciences > Library and Information Science
Refereed: No
Other ID: LIS027/IS90005
Date Deposited: 22 Apr 2013 16:12
Last Modified: 25 Aug 2017 05:03
URI: http://d-scholarship.pitt.edu/id/eprint/18336

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