The skyline operator

1. Which is skyline operator?
2. What is skyline query?
3. Which functions user can specify in query dimensions of a skyline query?
4. What is skyline of a dataset?

Which is skyline operator?

From Wikipedia, the free encyclopedia. The skyline operator is the subject of an optimization problem, used in a query to filter results from a database to keep only those objects that are not worse than any other. This operator is an extension to SQL proposed by Börzsönyi et al.

What is skyline query?

Given a dominance relationship in a dataset, a skyline query returns the objects that cannot be dominated by any other objects. Skyline queries were studied extensively in multidimensional spaces, in subspaces, in metric spaces, in dynamic spaces, in streaming environments, and in time-series data.

Which functions user can specify in query dimensions of a skyline query?

Dynamic Skyline Queries: A dynamic skyline query specifies an 'm' dimension function f ₁, f ₂, …, f _m , such that each function f _i (1 < i < m) takes as parameters the coordinates of the data points along a subset of d axes.

What is skyline of a dataset?

The concept of the skyline was proposed for the first time by Borzsonyi et al. (2001). They defined the skyline as a set of points which are not dominated by any other points in the dataset. ... A point is said to dominate other points when it is better on at least one dimension than the other points.