Results 301 to 310 of about 1,772,274 (338)

Partial strictness in two-phase locking

International Conference on Database Theory, 1995
Two-phase locking is a standard method for managing concurrent transactions in database systems. In order to guarantee good recovery properties, two-phase locking should be strict, meaning that locks can be released only after the transaction's commit or abort. In this paper we show that even exclusive locks can be released immediately after the commit
Eljas Soisalon-Soininen, Tatu Ylönen
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Performance limits of two-phase locking

[1991] Proceedings. Seventh International Conference on Data Engineering, 2002
A novel mean-value analysis method for two-phase locking (2PL) is presented which extends previous work to the important case of variable size transactions. The system performance expressed as the fraction of blocked transactions ( beta ) is determined by solving a cubic equation in beta whose coefficients are functions of a single parameter ( alpha ),
Alexander Thomasian
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Perfornance Study of Two Phase Locking in Single-Site Database Systems

IEEE Transactions on Software Engineering, 1987
Many database systems guarantee the consistency of the database for concurrent transaction processing by a standard locking protocol called two phase locking. The performance of such systems is dependent on various factors, among which are the choices of locking granularity (the amount of data controlled by a single lock) and degree of multiprogramming
Belford, Geneva G, Pun, KH
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Thrashing in two-phase locking revisited

[1992] Eighth International Conference on Data Engineering, 2003
The fraction of blocked transactions ( beta ) and the conflict rate, the ratio of locks held by all and active transactions, have been proposed as parameters to be monitored for load control. This study investigates the robustness of these parameters in the case of transactions requesting a variable number of locks and different processing times for ...
Alexander Thomasian
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Clarification of two phase locking in concurrent transaction processing

IEEE Transactions on Software Engineering, 1988
The authors propose a formal definition of the two-phase locking class derived from the semantic description of the two-phase locking protocol, and prove that this definition is equivalent to that given by C.H. Papadimitriou (1979). They present: (1) a precise definition of the two phase locking; (2) a clarification of the occurrence and the order of ...
Leu, Pei-Jyun, Bhargava, Bharat
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Design and analysis of a secure two-phase locking protocol

Proceedings Eighteenth Annual International Computer Software and Applications Conference (COMPSAC 94), 2002
In addition to maintaining consistency of the database, secure concurrency control algorithms must be free from covert channels arising due to data conflicts between transactions. The existing secure concurrency control approaches are unfair to transactions at higher access classes. A secure two-phase locking protocol is presented, which is correct and
S.H. Son, R. David
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The delay due to dynamic two-phase locking

IEEE Transactions on Software Engineering, 1989
An analytic formula for the delay due to two-phase locking is developed in terms of mean values for the input parameters using an open queuing network model in equilibrium. The results of simulations, using various realistic probability distributions governing the number of locks that transactions request, are presented to validate the formula ...
C. S. Hartzman
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On Using Priority Inheritance-Based Distributed Static Two-Phase Locking Protocol

2018
Two-phase locking with high priority (2PL-HP), a well-suited concurrency control protocol for distributed real-time database systems (DRTDBS) because of being free from priority inversion problem, is used for accessing data items to resolve conflicts among the concurrently executing transactions.
Sarvesh Pandey, Udai Shanker
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Performance Comparison of Static vs. Dynamic Two Phase Locking Protocols

Journal of Database Management, 1992
Queuing network models have been used extensively in the study of the performance of different concurrency control protocols in database systems. However, the results obtained are mostly qualitative in nature with few quantitative design rules which address performance issues such as data and resource contentions.
Sheung-Lun Hung, Kam-Yiu Lam
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A Case for Non-Two-Phase Locking Protocols that Ensure Atomicity

IEEE Transactions on Software Engineering, 1983
A transaction is atomic if it can be considered, as far as other transactions are concerned, to be indivisible and instantaneous even in the case of failure. An almost universally accepted way to ensure atomicity is to use a strict two-phase locking protocol with a roll-back scheme for recovery in case of deadlock or failure.
A. Silberschatz
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