Journal ArticleDOI
The notions of consistency and predicate locks in a database system
Reads0
Chats0
TLDR
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
More filters
Book ChapterDOI
Theory of concurrency control
TL;DR: This paper is a review of recent theoretical work on the problems which arise when many users access the same database.
Concurrency control in asynchronous computations
TL;DR: It is shown that isotach systems outperform conventional systems under workloads with atomicity and sequencing constraints, and a family of new cache coherence protocols called delta-cache protocols that extend isotach-based concurrency control techniques to systems that replicate and migrate shared variables, yielding protocols that are both scalable and more highly concurrent than existing protocols.
Journal ArticleDOI
Maintaining security and timeliness in real-time database system
Quazi N. Ahmed,Susan V. Vrbsky +1 more
TL;DR: This work presents two concurrency control algorithms for secure real-time databases: the Secure two-phase locking high priority (2PLHP) algorithm is based on a two- phase locking protocol and the Secure optimistic concurrence control (OPT) algorithm uses the properties of an optimistic concurrency protocol.
Book ChapterDOI
Data Management for Mobile Ad-Hoc Networks
TL;DR: The fundamental challenges of data management and processing in mobile ad-hoc networks are identified and ongoing and needed future work is outlined in order to achieve this goal.
References
More filters
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.