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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Proceedings ArticleDOI
Hierarchical database decomposition: a technique for database concurrency control
Meichun Hsu,Stuart E. Madnick +1 more
TL;DR: A new technique of concurrency control for database management systems has been proposed that makes use of a hierarchical database decomposition, a procedure which decomposes the entire database into data segments based on the access pattern of the update transactions to be run in the system.
Journal ArticleDOI
Multidimensional Timestamp Protocols for Concurrency Control
Pei-Jyun Leu,Bharat Bhargava +1 more
TL;DR: The timestamp in the protocols is constructed dynamically, not just based on the starting/finishing time as in conservative and optimistic timestamp methods, and thus the concurrency control can be enforced based on more precise dependency information derived from the operations of the transactions.
Performance Evaluation of Two-Shadow Speculative Concurrency Control
TL;DR: This paper evaluates the performance of the Two-Shadow SCC algorithm (SCC-2S), a member of the SCC-nS family, which is notable for its minimal use of redundancy.
Journal ArticleDOI
Resilient objects in broadband networks
TL;DR: Simulation results indicate that the number of messages needed to perform an operation increases slowly and the response time for performing an operation decreases as thenumber of copies increases, which is good news for resilient objects.
Journal ArticleDOI
Performance comparison of database concurrency control mechanisms based on two-phase locking, timestamping, and mixed approach
TL;DR: The effect of deadlocks, read : write ratio, cascade rollback, degree of concurrency, transaction-size mixes, transaction wait time and transaction blockings on the overall performance of seven different concurrency control algorithms are evaluated.
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.