Computational problems related to the design of normal form relational schemas
ACM Transactions on Database Systems (TODS)
Efficient optimization of a class of relational expressions
ACM Transactions on Database Systems (TODS)
Synthesizing third normal form relations from functional dependencies
ACM Transactions on Database Systems (TODS)
Multivalued dependencies and a new normal form for relational databases
ACM Transactions on Database Systems (TODS)
Independent components of relations
ACM Transactions on Database Systems (TODS)
A relational model of data for large shared data banks
Communications of the ACM
Optimal implementation of conjunctive queries in relational data bases
STOC '77 Proceedings of the ninth annual ACM symposium on Theory of computing
Analysis and design of relational schemata for database systems.
Analysis and design of relational schemata for database systems.
ACM SIGMOD Record
ACM SIGACT News
Testing implications of data dependencies
ACM Transactions on Database Systems (TODS)
Can we use the universal instance assumption without using nulls?
SIGMOD '81 Proceedings of the 1981 ACM SIGMOD international conference on Management of data
SIGMOD '81 Proceedings of the 1981 ACM SIGMOD international conference on Management of data
On equivalences of database schemes
PODS '82 Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems
A theory of data dependencies over relational expressions
PODS '82 Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems
An operational approach to data bases
PODS '82 Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems
Embedded implicational dependencies and their inference problem
STOC '81 Proceedings of the thirteenth annual ACM symposium on Theory of computing
Properties of acyclic database schemes
STOC '81 Proceedings of the thirteenth annual ACM symposium on Theory of computing
VLDB '80 Proceedings of the sixth international conference on Very Large Data Bases - Volume 6
What does Boyce-Codd normal form do?
VLDB '80 Proceedings of the sixth international conference on Very Large Data Bases - Volume 6
Annals of Mathematics and Artificial Intelligence
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We investigate the question of when two database schemes embody the same information. We argue that this question reduces to the equivalence of the sets of fixed points of the project-join mappings associated with the two database schemes in question. When data dependencies are given, we need only consider those fixed points that satisfy the dependencies. A polynomial algorithm to test the equivalence of database schemes, when there are no dependencies, is given. We also provide an exponential algorithm to handle the case where there are functional and/or multivalued dependencies. Furthermore, we give a polynomial time test to determine whether a project-join mapping preserves a set of functional dependencies, and a polynomial time algorithm for equivalence of database schemes whose project-join mappings do preserve the given set of functional dependencies. Lastly, we introduce the “update sets” approach to database design as an application of these results.