基于影子页面的MMDB的数据恢复方法

Recovery method for main memory database systems based on shadow paging

内存数据库数据主拷贝常驻内存,活动事务只与内存打交道,而由于内存的易失性,内存数据库的恢复成为内存数据库的核心技术。讨论了内存数据库的恢复技术,考虑所研究的系统环境限制,设计一种利用影子页面技术,并结合事务一致性检查点、模糊检查点思想,加上多版本技术的内存数据库恢复方法。该方法无需额外的硬件支持,解决了现有内存数据库恢复方法的一些问题。通过日志、检查点、恢复等方面来说明所设计的数据恢复方法,讲述它的备份过程和在事务故障和系统故障情况下恢复系统的过程。

In main memory database systems the main copies of the databases are memory-resident, the active transactions are only operated in main memory. Due to the volatility of main memory, database recovery becomes the crucial technique of MMDB. The recovery techniques of MMDB is discussed, and considering the limit of our system environment, a new method for MMDB recovery is designed. This method mainly utilizes the shadow paging technique, uses the transaction-consistent checkpoints and fuzzy checkpointing for reference, and imposes multiple versions techniques. Using these, the system doesn＇t need additional hardware, and some problems of the existing recovery methods are resolved more or less. Then the method is described by showing its logging, checkpointing and recoverying way, and the recovering process when the system crashed is explained.