Oracle中诊断阻塞的session
创建测试环境:TEST@ PROD> create table t(id int constraint pk_id2 primary key,val int);TEST@ PROD> select * from t; ID VAL---------- ---------- 1 &...
log file sync 和 log file parallel write
dbsnak在微博里这样描述等待事件log file sync和log file parallel write的关系: 前台进程a通知LGWR要刷log buffer了,这时候a就开始等待log file sync,LGWR接到a的请求后开始等待OS把log buffer写回redo log,...