Constant Delay Enumeration for Conjunctive Queries

Abstract

We survey some of the recent results about enumerating the answers to queries over a database. We focus on the case where the enumeration is performed with a constant delay between any two consecutive solutions, after a linear time preprocessing. This cannot be always achieved. It requires restricting either the class of queries or the class of databases. We consider conjunctive queries and describe several scenarios when this is possible.