Comparison and an Improved Validation Optimistic Approach for Concurrency Control

Concurrency Control entails the synchronization of accesses to the distributed database, such that the integrity of the database is maintained. Devising an efficient concurrency control technique is challenging. There is a need for improvised concurrency control technique to coordinate the simultaneous execution of transactions in a multi-processing database system. Traditionally, concurrency control techniques are locking, timestamp ordering and optimistic. These techniques have been evaluated by analytical modeling. In this undertaken work, the analytical modeling has been investigated and evaluated. The concurrency control in order to improve optimistic validation method with the traditional techniques, a new technique has been proposed.

Simulation Studies of Distributed Two-phase Locking in Distributed Database Management Systems

This paper considers algorithms simulating the implementation of distributed two-phase locking (2PL) protocols in distributed database systems and simulation results. It describes specifically the simulations of two-version 2PL and 2PL with integrated timestamp ordering mechanism. Integrated modelling algorithms for deadlock avoiding are suggested in the paper: twoversion architecture of database and timestamp ordering strategy “wait-die”. The results of the simulations of these two variants of the 2PL method at different scales of the networks for data transmission and at different intensities of inflow transactions are also presented. Modelling algorithms are developed by means of the system for simulation modelling GPSS World Personal Version.