Efficient Detection of Minimal Failing Subqueries in a Fuzzy Querying Context

摘要

This paper deals with conjunctive fuzzy queries that yield an empty or unsatisfactory answer set. We propose a cooperative answer­ing approach which efficiently retrieves the minimal failing subqueries of the initial query (which can then be used to explain the failure). The detection of the minimal failing subqueries relies on a prior step of fuzzy cardinalities computation. The main advantage of this strategy is to im­ply a single scan of the database. Moreover, the storage of such knowledge about the data distributions easily fits in memory.