Horn clauses and database dependencies (1982)
| Venue: | Journal of the ACM |
| Citations: | 49 - 6 self |
BibTeX
@ARTICLE{Fagin82hornclauses,
author = {Ronald Fagin},
title = {Horn clauses and database dependencies},
journal = {Journal of the ACM},
year = {1982},
volume = {29},
pages = {952--985}
}
Years of Citing Articles
OpenURL
Abstract
Abstract. Certain first-order sentences, called "dependencies, " about relations in a database are defined and studied. These dependencies seem to include all prewously defined dependencies as special cases 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. (An Armstrong relaUon is a relation that obeys precisely those dependencies that are the logical consequences of a given set of dependencies.) Results are also obtained about characterizing the class of projections of those relations that obey a given set of dependencies.







