自适应的数据库查询缓存

传统的缓存采取较为机械的管理方法，不能随数据库运行的动态信息调整自身参数以得到更优的性能。数据库语义缓存能够让数据库“理解”查询语义，可以为数据库的动态调节提供信息。而查询缓存是语义缓存的一种，在 SQL解析与查询执行之间，通过研究查询缓存的自主管理来提高数据库的查询性能。首先介绍了数据库常用的语义缓存与自主计算，然后对查询缓存进行了形式化定义，并提出了自适应的查询缓存模型。最后在MySQL的查询缓存上进行了实验，得到了较好的效果。

Adaptive cache for database query

In tradition,databases manage their caches in a relatively mechanical way and the cache can’t tune itself in dynamic environments.Semantic caching can make the database understand the query and provide the information needed in the dynamic tuning.Query cache is a kind of the semantic cache,between the SQL parser and the query executor.This paper does some research on the self-management of the database query cache,in order to improve the database performance.First some concepts of the database cache and the autonomic computing are introduced.Then,the formal definition of the query cache and the adaptive model are given.The experiment is done based on MySQL and the result is obvious.