scholarly journals A new distributed optimistic concurrency control method and a comparison of its performance with two-phase locking

2002 ◽  
Author(s):  
A. Thomasian ◽  
E. Rahm
Keyword(s):  
Concurrency Control ◽  
Control Method ◽  
Phase Locking ◽  
Two Phase ◽  
Optimistic Concurrency Control

scholarly journals Study of Concurrency Control Techniques in Distributed DBMS

2018 ◽  
Vol 2 (4) ◽  
Author(s):  
Manoj Kumar Gupta . ◽  
Rakesh Kumar Arora . ◽  
Bhoopesh Singh Bhati .
Keyword(s):  
Comparative Study ◽  
Concurrency Control ◽  
Phase Locking ◽  
Two Phase ◽  
Control Techniques ◽  
Very High

Concurrency control focuses on maintaining consistency and integrity of database through synchronized access. The complexity relating to concurrency control in a distributed context is very high as compared to centralized framework due to maintaining consistency within the multiple fragments / copies of the database. This paper consolidates and discusses various lock based concurrency control techniques for Distributed DBMS. The paper also presents a comparative study of various two phase locking based concurrency control techniques.

scholarly journals Concurrency Control in Database Systems

2019 ◽  
Vol 1 (2) ◽  
pp. 26-40
Author(s):  
Dardina Tasmere ◽  
Md. Nazmus Salehin
Keyword(s):  
Concurrency Control ◽  
Phase Locking ◽  
Wait Time ◽  
Arrival Rate ◽  
Database Systems ◽  
Control Algorithms ◽  
Control Mechanisms ◽  
Time Stamp ◽  
System Behavior ◽  
Two Phase

Concurrency control mechanisms including the wait, time-stamp and rollback mechanisms have been briefly discussed. The concepts of validation in optimistic approach are summarized in a detailed view. Various algorithms have been discussed regarding the degree of concurrency and classes of serializability. Practical questions relating arrival rate of transactions have been presented. Performance evaluation of concurrency control algorithms including degree of concurrency and system behavior have been briefly conceptualized. At last, ideas like multidimensional timestamps, relaxation of two-phase locking, system defined prewrites, flexible transactions and adaptability for increasing concurrency have been summarized.

On the efficiency of cautious schedulers for database concurrency control?Why insist on two-phase locking?

1989 ◽  
Vol 1 (2) ◽  
pp. 177-195 ◽  
Author(s):  
Shojiro Nishio ◽  
Shinichi Taniguchi ◽  
Toshihide Ibaraki
Keyword(s):  
Concurrency Control ◽  
Phase Locking ◽  
Two Phase

scholarly journals ALGORITMA ROCC

2003 ◽  
Vol 2 (1) ◽  
pp. 45
Author(s):  
F. BUKHARI ◽  
S. SULASNO
Keyword(s):  
Concurrency Control ◽  
Phase Locking ◽  
Two Phase ◽  
Transaction Manager

Algoritma concurrency control merupakan algoritma pengendalian akses konkurensi pada sistem sehingga objek yang diakses bersifat konsisten. Penelitian tentang concurrency control sudah dilakukan sejak 30 tahun lalu dan sudah banyak algoritma yang dihasilkan. Algoritma yang dihasilkan  umumnya menggunakan asumsi bahwa Transaction Manager adalah satu-satunya modul yang digunakan pengguna untuk mengakses objek. Sekarang ini akses terhadap objek dilakukan orang tidak hanya melalui Transaction Manager, tetapi juga melalui aplikasi internet. Pola tingkah laku transaksi melalui aplikasi internet berbeda dengan aplikasi tradisional. Algoritma concurrency control yang ada seperti two phase locking kurang tepat dan berkinerja buruk pada aplikasi internet. Untuk itu dibutuhkan suatu algoritma concurrency control baru yang sesuai dengan aplikasi internet. Shi dan Perizzo memperkenal algoritma ROCC (Read-commit Order Concurrency Control).  Banyak peneliti menilai algoritma ini sangat sesuai dengan aplikasi internet, tetapi algoritma ini melakukan restart yang tidak perlu. Penulis mencoba memperbaiki algoritma proses validasi sehingga restart dilakukan hanya pada akses atau transaksi yang tidak konsisten. Penelitian ini juga melakukan simulasi dalam upaya melihat perbedaan kinerja antara algoritma ROCC dan algoritma ROCC yang sudah diperbaiki.

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