Skyline Queries
نویسنده
چکیده
DEFINITION: Given a set of points p1, p2, ......., pn, the skyline query returns a set of points P, called as the skyline points, such that any point pi ∈ P is not dominated by any other point in the dataset. A point p1 dominates another point p2, if p1 is not worse than p2 in all dimensions and p1 is better than p2 in at least one dimension. In other words, a point p1 dominates another point p2, if and only if the coordinate of p1 on any axis is smaller than the corresponding coordinate of p2.
منابع مشابه
Computing Continuous Skyline Queries without Discriminating between Static and Dynamic Attributes
Although most of the existing skyline queries algorithms focused basically on querying static points through static databases; with the expanding number of sensors, wireless communications and mobile applications, the demand for continuous skyline queries has increased. Unlike traditional skyline queries which only consider static attributes, continuous skyline queries include dynamic attribute...
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Skyline evaluation techniques (also known as Pareto preference queries) follow a common paradigm that eliminates data elements by finding other elements in a data set that dominate them. Nowadays already a variety of sophisticated skyline evaluation techniques are known, hence skylines are considered a well researched area. On the other hand, the skyline operator does not stand alone in databas...
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There has been interest recently in skyline queries, also called Pareto queries, on relational databases. Relational query languages do not support search for “best” tuples, beyond the order by statement. The proposed skyline operator allows one to query for best tuples with respect to any number of attributes as preferences. In this work, we explore what the skyline means, and why skyline quer...
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In recent years, there has been much focus on skyline queries that incorporate and provide more flexible query operators that return data items which are dominating other data items in all attributes (dimensions). Several techniques for skyline have been proposed in the literature. Most of the existing skyline techniques aimed to find the skyline query results by supposing that the values of di...
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