Research On Interactive Multi-users Skyline Query Processing

With the rapid development of science and technology,the data show positive trends in high-dimensional and mass development.How to analyze big data and find out valuable information for users' decision-making is one of the focuses of research in database technology.Therefore,skyline query came into being.Most of the traditional skyline queries are carried out in a single-user environment.With the extensive application of the database in real life,it involves more than one user to participate in a query process.When using traditional skyline query technology to solve multi-users skyline queries,there will be deficiencies and shortcomings.Therefore,how to effectively obtain a skyline result set and meet the needs of multiple users at the same time is of great research significance.Combined with real-life scenarios,we study the multi-users skyline query processing technology for its characteristics.The main contributions of this paper are summarized as follows:(1)As traditional methods can't deal with multi-users skyline query problem under user's inequality,an algorithm named MUSW based on user's weights is proposed.The algorithm defines a measure of satisfaction,taking the proportion of users' weight into account.And it calculates the satisfaction of each user after the subspace skyline query processing.So it can effectively solve the integration problem of multi-users skyline query and control the number of output results.The algorithm is verified to be feasible,and it can effectively support the user's interaction.(2)Based on analysis of multi-users skyline query with attribute preference in data set,we proposes a multi-users preference skyline query algorithm based on attribute-priority relationship and named MUPS algorithm.The algorithm allows each member of the user group to give a preference definition for the priority of the attributes.It determines the initial attribute preference chain and the corresponding attribute weights by analyzing the preference query requirement of the user group.On the basis of this,a new method of domination named ?-dominate is put forward,which is for the purpose of pruning the original Skyline result.And by the interaction between user group and returned candidate set,the weight of each attribute in the attribute preference chain is dynamically amended to make the final result more in line with the real demand of the user group.The experimental results show that the MUPS algorithm can effectively solve the problem and has good interactive performance.(3)On the basis of solving the multi-users skyline query problem under the above two different application scenarios,the necessity of interaction in multi-user skyline query is deeply analyzed.So an interaction mechanism supporting multi-user skyline query is proposed.The overall framework of the interaction mechanism and its implementation process are given.Through the example analysis,it shows the effectiveness and scalability of the interaction mechanism.Finally,we design and implement a prototype system to support this interaction mechanism.