Optimal Algorithms for Ranked Enumeration of Answers to Full Conjunctive Queries.

ABSTRACT: We study ranked enumeration of join-query results according to very general orders defined by selective dioids. Our main contribution is a framework for ranked enumeration over a class of dynamic programming problems that generalizes seemingly different problems that had been studied in isolation. To this end, we extend classic algorithms that find the k-shortest paths in a weighted graph. For full conjunctive queries, including cyclic ones, our approach is optimal in terms of the time to return the top result and the delay between results. These optimality properties are derived for the widely used notion of data complexity, which treats query size as a constant. By performing a careful cost analysis, we are able to uncover a previously unknown trade-off between two incomparable en

SUBMITTER: Tziavelis N 

PROVIDER: S-EPMC7955775 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature