Reverse k-skyband query based on reuse technology
نویسندگان
چکیده
In this paper, we introduce a new approach to finish reverse k-skyband (RkSB) query which returns all the points in given dataset P whose dynamic k-skyband contains specific query object q. The main ideas include reuse technology and early stopping. The former save the information of node accesses during R-tree search into an auxiliary heap so that dramatically decreases the I/O cost and improves the CPU efficiency. This is because RkSB needs to execute global k-skyband and window query to finish the computation and the reuse information can be used in the phase of window query. The latter improves the efficiency of RkSB computation. The experimental results conducted on real datasets and synthetic datasets show that our proposed algorithm is effective and has a better performance both I/O cost and CPU efficiency than the algorithm based on reverse BBS (Branch and Bound Skyline) method. Keywordsalgorithm; skyline query; reverse skyline; skyband
منابع مشابه
Probabilistic k-Skyband Operator over Sliding Windows
Given a set of data elements D in a d-dimensional space, a k-skyband query reports the set of elements which are dominated by at most k − 1 other elements in D. k-skyband query is a fundamental query type in data analyzing as it keeps a minimum candidate set for all top-k ranking queries where the ranking functions are monotonic. In this paper, we study the problem of k-skyband over uncertain d...
متن کاملEffective Space Usage Estimation for Sliding-Window Skybands
Skyline query computes all the “best” elements which are not dominated by any other elements and thus is very important for decision-making applications. Recently, it is generalized to skyband query and a k-skyband query returns those elements dominated by no more than k, of other elements. To incorporate the skyband operator into the stream engine for monitoring skybands over sliding windows, ...
متن کاملEfficient Top-k Query Algorithms Using K-Skyband Partition
Efficient processing of top-k queries has become a classical research area. Fagin et al. proposed the “middleware cost” for a top-k query algorithm. In some scenario, there is no way to perform a random access, and Fagin et al. proposed NRA (No Random Access) algorithm for that. In this paper, we investigate the intrinsic relation between top-k queries and K-skyband queries. Based on that relat...
متن کاملReuse of Refinery Treated Wastewater in Cooling Towers
In this report, experimental investigation of waste water treatment by reverse osmosis to enable its reuse in cooling tower is presented. A polyamide spiral wound RO membrane followed by three filters as RO pretreatment (two activated carbon and one cartridge filter) and samples of Tehran refinery treated waste water have been used. The effect of operating conditions such as pressure differ...
متن کاملA Generic Framework for Top-k Pairs and Top-k Objects Queries over Sliding Windows
Top-k pairs and top-k objects queries have received significant attention by the research community. In this paper, we present the first approach to answer a broad class of top-k pairs and top-k objects queries over sliding windows. Our framework handles multiple top-k queries and each query is allowed to use a different scoring function, a different value of k and a different size of the slidi...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2013