Computational problems related to the design of normal form relational schemas
ACM Transactions on Database Systems (TODS)
Subset Dependencies and a Completeness Result for a Subclass of Embedded Multivalued Dependencies
Journal of the ACM (JACM)
Properties of functional-dependency families
Journal of the ACM (JACM)
A complete axiomatization for functional and multivalued dependencies in database relations
SIGMOD '77 Proceedings of the 1977 ACM SIGMOD international conference on Management of data
Principles of Database Systems
Principles of Database Systems
Data Models
Computers and Intractability: A Guide to the Theory of NP-Completeness
Computers and Intractability: A Guide to the Theory of NP-Completeness
Inferences involving embedded multivalued dependencies and transitive dependencies
SIGMOD '80 Proceedings of the 1980 ACM SIGMOD international conference on Management of data
Applying approximate order dependency to reduce indexing space
SIGMOD '82 Proceedings of the 1982 ACM SIGMOD international conference on Management of data
Functional Dependencies and Disjunctive Existence Constraints in Database Relations with Null Values
Proceedings of the 11th Colloquium on Automata, Languages and Programming
An extension of the relational data model to incorporate ordered domains
ACM Transactions on Database Systems (TODS)
Trends in Databases: Reasoning and Mining
IEEE Transactions on Knowledge and Data Engineering
Lexicographically Ordered Functional Dependencies and Their Application to Temporal Relations
IDEAS '99 Proceedings of the 1999 International Symposium on Database Engineering & Applications
Prioritized preferences and choice constraints
ER'07 Proceedings of the 26th international conference on Conceptual modeling
Differential dependencies: Reasoning and discovery
ACM Transactions on Database Systems (TODS)
Preference functional dependencies for managing choices
ER'06 Proceedings of the 25th international conference on Conceptual Modeling
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The notion of sort set is introduced here to formalize the fact that certain database relations can be sorted so that two or more columns are simultaneously listed in order. This notion is shown to be applicable in several ways to enhance the efficiency of an implemented database. A characterization of when order dependency implies the existence of sort sets in a database is presented, along with several corollaries concerning complexity, Armstrong relations, and cliques of certain graphs. Sort-set dependencies are then introduced. A (finite) sound and complete set of inference rules for sort-set dependencies is presented, as well as a proof that there is no such set for functional and sort-set dependencies taken together. Deciding logical implication for sort-set dependencies is proved to be polynomial, but if functional dependencies are included the problem is co-NP-complete. Each set of sort-set and functional dependencies is shown to have an Armstrong relation. A natural generalization of Armstrong relation, here called separator, is given and then used to study the relationship between order and sort-set dependencies.