Efficient Top-k Indexing via General Reductions
Saladi Rahul, Yufei Tao · 2016
Let D be a set of n elements each associated with a real-valued weight, and Q be the set of all possible predicates allowed on those elements. Given a predicate in Q and integer k, a top-k query returns the k elements with the largest weights among the elements of D satisfying q. The corresponding data structure problem aims to store D in small space to allow every query to be answered efficiently. It is already known that, before settling the problem, one must be able to solve two degenerated accompanying problems: (i) prioritized reporting: given a predicate q ∈ Q and a real value τ, return all the elements of D satisfying q and having weights at least τ (ii) max reporting: top-k queries with k fixed to 1.