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Article: IMPROVEMENT ALGORITHMS FOR SEMIJOIN QUERY PROCESSING PROGRAMS IN DISTRIBUTED DATABASE SYSTEMS.
Title | IMPROVEMENT ALGORITHMS FOR SEMIJOIN QUERY PROCESSING PROGRAMS IN DISTRIBUTED DATABASE SYSTEMS. |
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Authors | |
Keywords | Distributed database systems heuristic algorithms improvement algorithms optimality properties query optimization query processing relational data model semijoin programs |
Issue Date | 1984 |
Publisher | I E E E. The Journal's web site is located at http://www.computer.org/tc |
Citation | Ieee Transactions On Computers, 1984, v. C-33 n. 11, p. 959-967 How to Cite? |
Abstract | The problem of optimal query processing in distributed database system has been shown to be NP-hard. This means that heuristic algorithms are necessary to solve the query processing problem. Algorithms to improve the solutions generated by heuristics are described. Four properties have been identified that optimal semijoin programs for processing tree queries have to satisfy. A semijoin program is represented by an execution graph which specifies the order and the identities of the semijoins to be executed. Given a semijoin program, one can therefore apply these properties to check its optimality. If it does not satisfy these optimality properties, the associated improvement algorithms can be applied to improve this program. No assumptions have been made about the relation size and the selectivity of the semijoins. |
Persistent Identifier | http://hdl.handle.net/10722/154838 |
ISSN | 2023 Impact Factor: 3.6 2023 SCImago Journal Rankings: 1.307 |
DC Field | Value | Language |
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dc.contributor.author | Chen, Arbee LP | en_US |
dc.contributor.author | Li, Victor OK | en_US |
dc.date.accessioned | 2012-08-08T08:30:53Z | - |
dc.date.available | 2012-08-08T08:30:53Z | - |
dc.date.issued | 1984 | en_US |
dc.identifier.citation | Ieee Transactions On Computers, 1984, v. C-33 n. 11, p. 959-967 | en_US |
dc.identifier.issn | 0018-9340 | en_US |
dc.identifier.uri | http://hdl.handle.net/10722/154838 | - |
dc.description.abstract | The problem of optimal query processing in distributed database system has been shown to be NP-hard. This means that heuristic algorithms are necessary to solve the query processing problem. Algorithms to improve the solutions generated by heuristics are described. Four properties have been identified that optimal semijoin programs for processing tree queries have to satisfy. A semijoin program is represented by an execution graph which specifies the order and the identities of the semijoins to be executed. Given a semijoin program, one can therefore apply these properties to check its optimality. If it does not satisfy these optimality properties, the associated improvement algorithms can be applied to improve this program. No assumptions have been made about the relation size and the selectivity of the semijoins. | en_US |
dc.language | eng | en_US |
dc.publisher | I E E E. The Journal's web site is located at http://www.computer.org/tc | en_US |
dc.relation.ispartof | IEEE Transactions on Computers | en_US |
dc.subject | Distributed database systems | - |
dc.subject | heuristic algorithms | - |
dc.subject | improvement algorithms | - |
dc.subject | optimality properties | - |
dc.subject | query optimization | - |
dc.subject | query processing | - |
dc.subject | relational data model | - |
dc.subject | semijoin programs | - |
dc.title | IMPROVEMENT ALGORITHMS FOR SEMIJOIN QUERY PROCESSING PROGRAMS IN DISTRIBUTED DATABASE SYSTEMS. | en_US |
dc.type | Article | en_US |
dc.identifier.email | Li, Victor OK:vli@eee.hku.hk | en_US |
dc.identifier.authority | Li, Victor OK=rp00150 | en_US |
dc.description.nature | link_to_subscribed_fulltext | en_US |
dc.identifier.scopus | eid_2-s2.0-0021526448 | en_US |
dc.identifier.volume | C-33 | en_US |
dc.identifier.issue | 11 | en_US |
dc.identifier.spage | 959 | en_US |
dc.identifier.epage | 967 | en_US |
dc.publisher.place | United States | en_US |
dc.identifier.scopusauthorid | Chen, Arbee LP=7403391667 | en_US |
dc.identifier.scopusauthorid | Li, Victor OK=7202621685 | en_US |
dc.identifier.issnl | 0018-9340 | - |