Incomplete relations are relations which contain null values, whose meaning is \value is at present unknown". Such relations give rise to two types of functional dependency (FD). The rst type, called the strong FD (SFD), is satissed in an incomplete relation if for all possible worlds of this relation the FD is satissed in the standard way. The second type, called the weak FD (WFD), is satissed...

Functional dependencies restrict the potential interactions among variables connected in a probabilistic network. This restriction can be exploited in qualitative probabilistic reasoning by introducing deterministic variables and mod­ ifying the inference rules to produce stronger conclusions in the presence of functional rela­ tions. I describe how to accomplish these modi­ fications in qualit...

Functional dependencies form an important class of integrity constraints which has been well studied in the context of relational databases. Recently, the eXtensible Markup Language (XML) has emerged as a popular and flexible standard for modelling and managing data in a variety of domains. Although several attempts have been made to generalise the concept of functional dependencies to the cont...

This paper proposes a kind of PAC (Probably Approximately Correct) learning framework for inferring a set of functional dependencies. A simple algorithm for inferring the set of approximate functional dependencies from a subset of a full tuple set (i.e. a set of all tuples in the relation) is presented. It is shown that the upper bound of the sample complexity, which is the number of example tu...

Previous work on type inference for functional dependencies demands that the dependency must fully cover all parameters of a type class to guarantee that the constraint solver is confluent. However, several interesting programs rely on non-full functional dependencies. For these, the underlying constraint is nonconfluent, and hence type inference for these programs is possibly ill-behaved. We i...

The World Wide Web is of strategic importance as a global repository for information and a means of communicating and sharing knowledge. Its explosive growth has caused deep changes in all the aspects of human life, has been a driving force for the development of modern applications (e.g., Web portals, digital libraries, wrapper generators, etc.), and has greatly simplified the access to existi...

This is an inquiry into the “actionable credibility” of information values in informing and how it depends on indirect attributes of information quality. Empirical survey-based research by Wang and Strong (1996) ignores the multidimensional aspects of credibility. Studies that ignore them may produce unreliable results. Most publications discuss quality attributes as independent factors. This p...

Conditional functional dependencies (CFDs) have been recently introduced in the context of data cleaning. They can be seen as an unification of functional dependencies (FDs) and association rules (AR) since they allow to mix attributes and attribute/values in dependencies. In this paper, we introduce our first results on constant CFD inference. Not surprisingly, data mining techniques developed...

Functional dependency is one of the most extensively researched subjects in database theory, originally for improving quality of schemas, and recently for improving quality of data. In a payas-you-go data integration system, where the goal is to provide best-effort service even without thorough understanding of the underlying domain and the various data sources, functional dependency can play a...

We study keys and functional dependencies in the context of partial relations that permit null values with the interpretation no information. Based on Codd’s principle of entity integrity we propose the class of strong keys over partial database relations. These keys enforce both uniqueness and totality of tuples. We study the interaction of strong keys with Lien, Atzeni and Morfuni’s classes o...