随笔分类 -  名词解释

摘要：checkpoint目的是减少数据库的恢复时间(服务奔溃或重启服务后的恢复),而lazy writer的目的是保证SQL OS 有空闲缓存块和系统有一定可用内存。Checkpoint和lazyWriter都会将缓冲区内脏页写入到磁盘；lazywriter会更新缓存区空闲可用列表，而checkpoint不会；checkpoint操作会被记录到数据库日志中，而lazywriter不会；checkpoint的触发条件1. 自上次检查点后产生大量日志2. 服务实例关闭3. 数据库完整备份或差异备份(日志备份不会触发checkpoint)4. 数据库恢复模式为简单恢复模式下当日志文件使用超过70%时la 阅读全文

摘要：Q:What Does the LazyWriter Process Do?The LazyWriter process is a periodic process that checks the status of BPool buffers (committed or not committed)in a cycle and evaluates if it needs to increase or decrease the number of committed buffers according to the memory required by SQL Server and memor 阅读全文

摘要：中文简介CRUD是指在做计算处理时的增加(Create)、查询(Retrieve)（重新得到数据）、更新(Update)和删除(Delete)几个单词的首字母简写。主要被用在描述软件系统中数据库或者持久层的基本操作功能。英文释义In computing, CRUD is an acronym for create, retrieve, update, and delete. It is used to refer to the basic functions of a database or persistence layer in a software system.C reate new 阅读全文