Properties of functional-dependency families

@article{Ginsburg1982PropertiesOF,
  title={Properties of functional-dependency families},
  author={Seymour Ginsburg and Sami Mohammed Zaiddan},
  journal={J. ACM},
  year={1982},
  volume={29},
  pages={678-698}
}
A functional-dependency (FD-) family Is defined here as the family of all instances satisfying a set of functional dependencies These families are studied with respect to projection, join, and decomposition and their connection with generating families and generators Typical results obtained are (0 a charactenzauon for when the projection of an FD-family is an FD-family; 00 a charactenzauon for when the join of two FD-famihes is an FD-famdy, (m) a necessary and sufficient condition for an F D… 
Characterizations for Functional Dependency and Boyce-CODD Normal Form Families
A functional dependency (fd) family was recently defined [20] as the set of all instances satisfying some set of functional dependencies. A Boyce-Codd normal form, abbreviated BCNF, family is defined
Non-Finite Specifiability of Projections of Functional Dependency Families
  • R. Hull
  • Computer Science, Mathematics
    Theor. Comput. Sci.
  • 1985
TLDR
It is shown here that if the projection of an FD family is not anFD family, then it is not a finitely specifiable ID family.
On the Structure of Armstrong Relations for Functional Dependencies
TLDR
It is shown that the time complexity of finding an Armstrong relation, a relation that satisfies each FD implied by the set but no FD that is not implied by it, is precisely exponential in the number of attributes.
Propagating functional dependencies with conditions
TLDR
This paper investigates dependency propagation for recently proposed conditional functional dependencies (CFDs) and provides the first algorithm for computing a minimal cover of all CFDs propagated via SPC views, and extends the classical work of FD propagation by giving new complexity bounds in the presence of finite domains.
Sort sets in the relational model
TLDR
A characterization of when order dependency implies the existence of sort sets in a database is presented, along with several corollaries concerning conplexlty, Armstrong relations and cliques of certain graphs.
Tools for Template Dependencies
TLDR
Template dependencies (TD’s) are a class of data dependencies that include multivalued and join dependencies and embedded versions of these and there are weakest (nontrivial) and strongest full TDs over any given set of attributes.
On the expressive power of data dependencies
TLDR
The technique is model-theoretic, and the characterization easily entails all previously known results on axiomatizability by dependencies.
Armstrong Databases for Functional and Inclusion Dependencies
TLDR
It is shown that if the sentences of interest are inclusion dependencies and standard functional dependencies (functional dependencies for which the left-hand side is nonempty), then there is always an Armstrong database for each set of sentences.
Horn clauses and database dependencies
TLDR
A new concept is mtroduced, called "faithfulness (with respect to direct product)," which enables powerful results to be proved about the existence of "Armstrong relations" in the presence of these new dependencies.
Extending dependencies for improving data quality
TLDR
This doctoral thesis proposes five classes of data dependencies to capture data inconsistencies commonly found in practice in a centralized environment, and provides the first algorithm for computing a minimal cover of all CFDs propagated via SPCViews, despite the increased expressive power of CFDs and SPC views.
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It is shown that the time complexity of finding an Armstrong relation, a relation that satisfies each FD implied by the set but no FD that is not implied by it, is precisely exponential in the number of attributes.
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