Research On Recovery Technology Of Main Memory Database

With the rapid development of computer technology,many real-time application systems about data recovery with strong time constraint emerge,such as telephone switching applications,mobile computer applications,securities trading applications and so on. Although there are a lot of technologies for data recovery at home and abroad,all of these recovery technologies have some defects because they basically employ logging, checkpointing, reloading to ensure the rapid recovery of the database to a consistent state,and cannot satisfy the requirements of real-time application system. Therefore,effective and fast Main Memory Database Recovery technologies have some practical value and theoretical significance.Basing on Song's No-Log Recovery Mechanism, a two-step backup mechanism is proposed in this thesis by combining shadow memory technology and adding stable memory. The first backup step is done from shadow memory to backup buffer area and the second backup step is performed from backup buffer area to backup disk. Compared to conventional recovery technologies, the two-step backup mechanism needn't write logs, which can not only reduce the recovery time, but also ensure the rapid response. Futhermore, the mechanism avoids the conflicts by performing transaction processing and backup processing in separate areas.Firstly, the background and significance of the research are introduced in the thesis. Secondly, the thesis describes the definition, development process and related products of Main Memory Database,analyzes the current development status of Main Memory Database at home and abroad, and compares Main Memory Database with Disk Resident Database in some aspects. Thirdly, the thesis describes the compositions of Main Memory Database recovery technologies. Then, the thesis describes several current representative recovery technologies that have been improved, based on the traditional recovery technologies and analyzes their advantages and disadvantages. Finally, the thesis gives descriptions in detail to the recovery technologies based on two-step backup mechanism and predicts the future directions of the Main Memory Database.