In this paper we improve TPM (transaction processing monitor) and aim at a further performance enhancement of PostgreSQL. Therefore we examined introduction of mechanism to change dynamically the number of the server connections to solve the problem in this study. We investigate the number of the most suitable connection by the load situation for this introduction, and we design TPM again in various points such as the design of the mechanism to analyze server state and the design of a mechanism to change the number of the connections. We report the result of the research, the contents of design, implementation and evaluation in this paper.