An analysis of the effect of multiversions on the performance of timestamp algorithms

The performance of a multiversion conservative timestamp algorithm is evaluated by analyzing the response time of operations in a distributed database system. The random communication delay in the transmission channels of a long-haul network supporting the distributed database system causes transmitted operations to be received out of order. According to rules that are dependent on the number of versions, the scheduler reorders the operations to preserve the consistency of the database. Operations encounter extra delay in the process of reordering. The system is modeled by a queuing network. Response-time distributions are obtained analytically. Numerical results are presented to show the effect of the number of versions on the performance.<
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