1. A skyline query system for implementing a skyline query, comprising: a sky quad tree generator that generates a quad tree from data, and marks a leaf node, which cannot include a local skyline, as being dominated; a local skyline calculator that computes a local skyline of each leaf node, which is not marked as being dominated, in the sky quad tree; and a global skyline calculator that computes a global skyline by using the local skyline, wherein the skyline query is a query for calculating a skyline, a dynamic skyline, or a reverse skyline from the data, and each of the local skyline and the global skyline is a skyline, a dynamic skyline or a reverse skyline.