Results 221 to 230 of about 36,093 (262)
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Watermarking Relational Databases
2002We enunciate the need for watermarking database relations to deter their piracy, identify the unique characteristics of relational data which pose new challenges for watermarking, and provide desirable properties of a watermarking system for relational data.
Rakesh Agrawal 0001, Jerry Kiernan
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Entities and relations for historical relational databases
Proceedings of TIME '97: 4th International Workshop on Temporal Representation and Reasoning, 2002Research to extend models of data to handle the temporal dimension has been conducted mainly in the context of the relational data model. In the relational model, the primary object of database design, manipulation and retrieval is the relation, viewed extensionally as a finite set of tuples. This paper proposes three useful types of temporal entities:
Robert A. Morris 0001, Lina Khatib
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Metaprogramming for Relational Databases
2004For systems that share enough structural and functional commonalities, reuse in schema development and data manipulation can be achieved by defining problem-oriented languages. Such languages are often called domainspecific, because they introduce powerful abstractions meaningful only within the domain of observed systems.
Jernej Kovse +2 more
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Equivalence of relational database schemes
Proceedings of the eleventh annual ACM symposium on Theory of computing - STOC '79, 1979We 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.
Catriel Beeri +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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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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Relational Scaling and Databases
2002More than 20 years of theoretical development and practical experience in the field of Conceptual Information Systems have made available a wide variety of structure and procedures to gain new knowledge from data or to present it in a user-friendly way, by restructuring the data in a conceptual way to help the user interpret and understand the meaning.
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On decomposition of relational databases
23rd Annual Symposium on Foundations of Computer Science (sfcs 1982), 1982A central issue in relational database theory is that of decomposition. It has been agreed that decompositions should be injective, so as not to lose information, and surjective, so they decompose a relation into independent components. Injectiveness and surjectiveness are in general second-order notions.
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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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