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Journal ArticleDOI

The notions of consistency and predicate locks in a database system

Kapali P. Eswaran, +3 more
- 01 Nov 1976 - 
- Vol. 19, Iss: 11, pp 624-633
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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.

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Scheduling real-time transactions: a performance evaluation

TL;DR: This thesis develops a new family of algorithms for scheduling real-time transactions and proposes new techniques for handling requests without deadlines and requests with deadlines simultaneously, finding that real- time disk scheduling algorithms can perform better than conventional algorithms.
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.
Book

Introduction to Metamathematics

H. Rasiowa
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.