政大機構典藏-National Chengchi University Institutional Repository(NCCUR):Item 140.119/69378

English | 正體中文 | 简体中文 | Post-Print筆數 : 27 | Items with full text/Total items : 113656/144643 (79%)
Visitors : 51716070 Online Users : 620

RC Version 6.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.

Home ‧ Login ‧ Upload ‧ Help ‧ About ‧ Administer

政大機構典藏 > 資訊學院 > 資訊科學系 > 期刊論文 > Item 140.119/69378

Please use this identifier to cite or link to this item: https://nccur.lib.nccu.edu.tw/handle/140.119/69378

Title:	An Optimal Algorithm for Processing Distributed Star Queries
Authors:	陳良弼 Chen,Arbee L. P;Li, V.O.K.
Contributors:	資科系
Date:	1985-10
Issue Date:	2014-08-28 10:08:42 (UTC+8)
Abstract:	The problem of optimal query processing in distributed database systems was shown to be NP-hard. However, for a special type of queries called star queries, we have developed a polynomial optimal algorithm. Semijoin tactics are applied for query processing. An execution graph is introduced to represent the semijoin programs associated with the distributed processing of the queries. We then identify optimality properties of semijoin programs for star queries, and use these properties to derive the optimal semijoin program. We have shown that the optimal semijoin program can be found from serial semijoin strategies, defined as serial semijoin programs which include each semijoin associated with the query exactly once. By making certain assumptions on the file sizes and the semijoin selectivities, we can obtain the optimal semijoin program from these strategies in polynomial time. Our assumption on selectivites is consistent in the sense that we consider the selectivity of a semijoin based on the current database state, i.e., we take into consideration the reduction effects of all prior semijoins.
Relation:	IEEE Transactions on Software Engineering (SCI,EI),1097-1107
Data Type:	article
Appears in Collections:	[資訊科學系] 期刊論文

Files in This Item:

File	Description	Size	Format
index.html		0Kb	HTML2	1218	View/Open

社群 sharing

著作權政策宣告 Copyright Announcement

1.本網站之數位內容為國立政治大學所收錄之機構典藏，無償提供學術研究與公眾教育等公益性使用，惟仍請適度，合理使用本網站之內容，以尊重著作權人之權益。商業上之利用，則請先取得著作權人之授權。
The digital content of this website is part of National Chengchi University Institutional Repository. It provides free access to academic research and public education for non-commercial use. Please utilize it in a proper and reasonable manner and respect the rights of copyright owners. For commercial use, please obtain authorization from the copyright owner in advance.

2.本網站之製作，已盡力防止侵害著作權人之權益，如仍發現本網站之數位內容有侵害著作權人權益情事者，請權利人通知本網站維護人員(nccur@nccu.edu.tw)，維護人員將立即採取移除該數位著作等補救措施。
NCCU Institutional Repository is made to protect the interests of copyright owners. If you believe that any material on the website infringes copyright, please contact our staff(nccur@nccu.edu.tw). We will remove the work from the repository and investigate your claim.

Loading...