Preference functional dependencies for managing choices

摘要: The notion of user preference in database modeling has recently received much attention advanced applications, such as personalization e-services, since it captures the human wishes on querying and managing data. paradigm preference-driven choices real world requires new semantic constraints modelling. In this paper, we assume can be defined over data domains thus assumption gives rise to relations a special case ordered schemas consisting preference, preferencedependent preference-independent attributes. We demonstrate that Lexicographically Ordered Functional Dependencies (LOFDs) employed maintain consistency semantics embedded database, prioritized multiple preferences represented. define useful constraint terms set LOFDs, called Preference (PFDs), order capture ranked exhibit sound complete axiom system for PFDs, whose implication problem is shown decidable polynomial-time. also confirm existence Armstrong fundamental result related practical use PFDs design.