Research On Self-tuning Technology Of DM4 Database

The performance of DBMS is a very important research subject. Recent years, the self-tuning DBMS become more and more import. This paper researches the self-tuning design of DM4 network subsystem and I/O subsystem. The main principle that we pursued in the self-tuning design of DM4 network subsystem and I/O subsystem is the concept of an online feedback control loop. This loop consists of five subsystems: the network subsystem of DM4, the I/O subsystem of DM4, the performance monitor subsystem of DM4, the performance analysis subsystem of DM4, and the performance adjust subsystem of DM4. The performance monitor subsystem collects performance data of the network subsystem and I/O subsystem. The performance analysis subsystem analyzes the data that monitor subsystem gathers by simple queueing analysis method, and whenever the performance metrics exceed critical thresholds, the performance adjust subsystem dynamically adjusts some parameters by hill climbing method.In the network subsystem, we give a queueing network communication model which uses the multipling-thread technology and the asynchronous network communication technology. In the I/O subsystem, we give an asynchronous I/O model based on Windows and Linux.From the automatic tuning technology of DM4 system, a major conclusion is that self-tuning database technology should be based on the paradigm of a feedback control loop. In addition, the database management system may require a radical depature towards simpler, highly componentized software architectures with narrow interfaces between RISC-style "autonomic" components.