Database Systems (TODS)


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ACM Transactions on Database Systems (TODS), Volume 16 Issue 1, March 1991

A rule-based language with functions and sets
Serge Abiteboul, Stéphane Grumbach
Pages: 1-30
DOI: 10.1145/103140.103141
A logic based language for manipulating complex objects constructed using set and tuple constructors is introduced. A key feature of the COL language is the use of base and derived data functions. Under some stratification restrictions, the...

Functional dependencies in Horn clause queries
Alberto O. Mendelzon, Peter T. Wood
Pages: 31-55
DOI: 10.1145/103140.103142
When a database query is expressed as a set of Horn clauses whose execution is by top-down resolution of goals, there is a need to improve the backtracking behavior of the interpreter. Rather than putting on the programmer the onus of using...

The complexity of operations on a fragmented relation
C. Meghini, C. Thanos
Pages: 56-87
DOI: 10.1145/103140.103143
Data fragmentation is an important aspect of distributed database design, in which portions of relations, tailored to the specific needs of local applications, are defined to be further allocated to the sites of the computer network supporting...

A model of authorization for next-generation database systems
Fausto Rabitti, Elisa Bertino, Won Kim, Darrell Woelk
Pages: 88-131
DOI: 10.1145/103140.103144
The conventional models of authorization have been designed for database systems supporting the hierarchical, network, and relational models of data. However, these models are not adequate for next-generation database systems that support richer...

Principles and realization strategies of multilevel transaction management
Gerhard Weikum
Pages: 132-180
DOI: 10.1145/103140.103145
One of the demands of database system transaction management is to achieve a high degree of concurrency by taking into consideration the semantics of high-level operations. On the other hand, the implementation of such operations must pay...

The multicast policy and its relationship to replicated data placement
Ouri Wolfson, Amir Milo
Pages: 181-205
DOI: 10.1145/103140.103146
In this paper we consider the communication complexity of maintaining the replicas of a logical data-item, in a database distributed over a computer network. We propose a new method, called the minimum spanning tree write, by which a processor...