To help a user specify and verify quantified queries -a class of database queries known to be very challenging for all but the most expert users -one can question the user on whether certain data objects are answers or non-answers to her intended query. In this paper, we analyze the number of questions needed to learn or verify qhorn queries, a special class of Boolean quantified queries whose underlying form is conjunctions of quantified Horn expressions. We provide optimal polynomial-question and polynomial-time learning and verification algorithms for two subclasses of the class qhorn with upper constant limits on a query's causal density.
It assumes that the user can specify the value assignments used in his intended query, and learns conjunctions of quantified Horn expressions (with if-then semantics) over nested relations REF .
Learning and verifying quantified boolean queries by example
PODS '13
Computer Science