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Research On Technique Of Multi-subspace Skyline Query Processing

Posted on:2018-06-13Degree:MasterType:Thesis
Country:ChinaCandidate:X Y WangFull Text:PDF
GTID:2348330536487926Subject:Computer Science and Technology
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As the rapid development of information technology,people have to deal with more and more data and data dimensions are also increasing.So how to quickly analyze the complex data and to get more valuable information from data becomes an urgent requirement.As an effective means of data analysis,skyline query plays a more and more important role in the studies of database.The existing skyline query processing methods meanly consist of full-space skyline query and subspace skyline query.But when dealing with volume and high-dimensional data,full-space skyline query has several disadvantages such as oversize result set and poor efficiency.As a result,subspace skyline query has more important research significance.Based on the fully adequate analysis of existing skyline query technology,and combining with the application scenarios in life,we study the multi-subspace skyline query processing technology.The main contributions of this paper are summarized as follows:(1)As existing methods can't solve arbitrary number of subspace skyline queries,we propose an efficient algorithm to solve the multi-subspace skyline query problem.First we propose a structure of subspace cubes group.Then we make full use of the sharing relationship between the skyline result sets of each subspace by using the subspace candidate set.In addition,we use sum filter and maximum filter to further improve the efficiency of our algorithm.At last we show the effectiveness and practicability of the algorithm by experiments.(2)Based on above problem,we further propose a multi-preference optimal group query problem.This problem is aimed at one user or a group of users finding combinations in practical application.Based on the multi-subspace skyline query algorithm,an efficient algorithm to solve multi-preference optimal group query problem is proposed.This algorithm allows users to put forward their own preference definitions for each member of the target group,and finally returns the optimal groups as the query result.The algorithm ensures that the size of the result set is controllable by cutting the intermediate results.In addition,we add the dynamic output mechanism to the algorithm,which ensures the gradualness of the algorithm.Users can terminate the query process at any time after they get the satisfactory groups.(3)In order to apply the above two kinds of queries to database management system,we extend the SQL to support the semantic of multi-subspace skyline query and multi-preference optimal group query.First we design the syntax of the extended SQL.Then we complete an archetype database system to support the above two kinds of queries.The system is based on a self-developed database management system of our research team.
Keywords/Search Tags:Skyline query, Subspace, Multi-subspace Skyline Query, Preference, Group Query, Database Management System
PDF Full Text Request
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