Journal ArticleDOI
The notions of consistency and predicate locks in a database system
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It is argued that a transaction needs to lock a logical rather than a physical subset of the database, and an implementation of predicate locks which satisfies the consistency condition is suggested.Abstract:
In database systems, users access shared data under the assumption that the data satisfies certain consistency constraints. This paper defines the concepts of transaction, consistency and schedule and shows that consistency requires that a transaction cannot request new locks after releasing a lock. Then it is argued that a transaction needs to lock a logical rather than a physical subset of the database. These subsets may be specified by predicates. An implementation of predicate locks which satisfies the consistency condition is suggested.read more
Citations
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Journal ArticleDOI
Theseus—a programming language for relational databeses
TL;DR: Theseus as discussed by the authors is a very high-level programming language extending EUCLID, which includes relations and a-sets, a generalization of records, and is designed to facilitate the writing of well-structured programs for database applications and serve as a vehicle for research in automatic program optimization.
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A Fast Transaction-Oriented Logging Scheme for Undo Ro overy
TL;DR: A special UNDO log algorithm combining the advantages of update in place strategies with the shadow page concept is introduced to support applications demanding high rates of possibly long update transactions as well as fast UNDO recovery.
Proceedings ArticleDOI
Semantic locking in object-oriented database systems
TL;DR: A semantic locking protocol is presented for transaction management for object-oriented databases that incorporates the semantics of complex objects, nested executions and dynamic conflicts resulting from referentially shared objects.
Journal ArticleDOI
Applications of graph grammar theory to consistency, synchronization and scheduling in data base systems
Hartmut Ehrig,Hans-Jörg Kreowski +1 more
TL;DR: Results from graph grammar theory are able to show that for each schedule there is a unique optimal one, and a degree of non-parallelism for schedules is defined such that optimal schedules are those with minimal degree with respect to all equivalent ones.
Journal ArticleDOI
Building knowledge base management systems
TL;DR: The paper describes original results, including novel data structures and algorithms, as well as preliminary performance evaluation data, and concludes that knowledge base management systems which can accommodate large knowledge bases are feasible.
References
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Journal ArticleDOI
A relational model of data for large shared data banks
TL;DR: In this article, a model based on n-ary relations, a normal form for data base relations, and the concept of a universal data sublanguage are introduced, and certain operations on relations are discussed and applied to the problems of redundancy and consistency in the user's model.
Proceedings ArticleDOI
Recovery semantics for a DB/DC system
TL;DR: A unified, systematic view of integrity/recovery as it relates to a data-processing system—whether man, machine, or both is presented.
Proceedings ArticleDOI
Recovery scenario for a DB/DC system
TL;DR: Previously developed sphere-of-control (SOC) concepts are used to develop a scenario for post-process recovery where an information structure provides the recovery boundary around the effects of the usage of a resource.