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Compiling subsumption to relational databases
Intelligenza Artificiale: The international journal of the AIxIA, 2013We investigate on the possibility of transforming concepts in Description Logics into relational databases and queries in such a way that subsumption between the original concepts can be decided as query answering over a database. For the positive results, we show a translation of -concepts into pairs (database, query) such that, in order to decide ...
Eufemia Tinelli +2 more
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A Virtual XML Database Engine for Relational Databases
2003While XML is emerging as the universal format for publishing and exchanging data on the Web, most business data is still stored and maintained in relational DBMSs. To enable eBusiness database applications, Web access to the legacy data managed by DBMSs needs to be provided.
Chengfei Liu +3 more
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Assumptions in relational database theory
Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems, 1982Many results in relational database theory on the structure of dependencies, query languages, and databases in general have now been established. However, neither (a) the reliance of these results on various assumptions, nor (b) the desirability or reasonableness of these assumptions themselves have been closely examined.
ATZENI, Paolo, PARKER DS
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Answering queries in relational databases
ACM SIGMOD Record, 1983This paper concerns query answering in relational databases. We assume a universe U of attributes and a set of values associated with each attribute. A database scheme is a given collection R = {1, 2, ..., n} of subsets of U, called relation schemes. A query in R is any subset of U. We call "context" any joinable subset of R.
D'ATRI, ALESSANDRO +2 more
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IEEE Transactions on Knowledge and Data Engineering, 1993
The concept of an inductive relation is introduced, as a natural development of other forms of intentional information, such as views and relations defined deductively. A class of top-down methods for computing such inductive relations is analyzed. Major problems produced by recursive and interdependent relations are considered. >
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The concept of an inductive relation is introduced, as a natural development of other forms of intentional information, such as views and relations defined deductively. A class of top-down methods for computing such inductive relations is analyzed. Major problems produced by recursive and interdependent relations are considered. >
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Incomplete Information in Relational Databases
Journal of the ACM, 1984ABSTRACT This paper concerns the semantics of Codd's relational model of data. Formulated are precise conditions that should be satisfied in a semantically meaningful extension of the usual relational operators, such as projection, selection, union, and join, from operators on relations to operators on tables with “null values” of various kinds ...
Tomasz Imielinski, Witold Lipski Jr.
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An Algebraic Theory of Relational Databases
Bell System Technical Journal, 1983In this paper we present a theory of relational database systems based on the partition lattice, which represents a new mathematical approach to the structure of relational database systems. A partition lattice can be defined for any given relation.
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ACM SIGMOD Record, 1989
This paper discusses the semantic issues related to null values problem in relational databases. We argue that the proposed set of maybe operations with the three valued logic is still not adequate and needs further enhancements.
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This paper discusses the semantic issues related to null values problem in relational databases. We argue that the proposed set of maybe operations with the three valued logic is still not adequate and needs further enhancements.
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On the normalization of relational databases
Information Processing Letters, 1979B. Srinivasan, V. Rajaraman
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