Dynamic skyline queries are practical in many applications. For example, in an information system, if no data exist to fully satisfy a query q, the data “closer” to the requirements of q can be retrieved as the answers. Finding the nearest neighbors of q can be a solution; yet finding the data not dynamically dominated by any other data with respect to q, i.e. the dynamic skylines regarding q can be another solution. A data point p is defined to dynamically dominate the other data point s, if the distance between each dimension of p and the corresponding dimension of q is no larger than the corresponding distance regarding s and q, and moreover, at least in one dimension, the corresponding distance regarding p and q is smaller than that regarding s and q. Some approaches for answering dynamic skyline queries have been proposed in recent years. However, the existing approaches only consider the query as a point rather than a range in each dimension, which can also be frequently issued by users. We therefore make the first attempt to solve the problem of computing dynamic skylines considering range queries in this paper. To deal with this problem, we propose an efficient algorithm based on the grid index and a novel variation of the well-known Z-order curve. Moreover, a series of experiments are performed to evaluate the proposed algorithm and the experiment results demonstrate that it is effective and efficient.

在很多應用中都有用到動態天際線的查詢，列如，在一個資訊系統中，如果沒有任何資料符合查詢，那麼接近其他查詢的資料就會被當成答案回報給使用者；與查詢鄰近的那些資料可以當作答案回傳給使用者，但是找到那些針對於查詢而言沒有被動態支配的那些資料也可以當作答案回傳給使者。動態支配的意思是，我們說一個資料點p動態支配另一個資料點s，那麼p在所有維度中距離使用者下的查詢都不會大於s到使用者下的查詢的距離，更甚的是，至少有一個維度p到查詢的距離為小於s到查詢的距離。近年來有些有解決動態天際線的方法被提出來，然而，現存的方法都考慮查詢是一個精確值，而非是一個範圍，因此我們是第一個研究如何在範圍查詢之下解決動態天際線的計算，我們提出了一個和有效率的演算法，演算法是建構在格網索引和一個Z曲線的變型。最後實驗部分展示出了我們方法的效率。

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