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Oracle10G:ash的采样机制

程序员文章站 2023-10-11 20:19:40
ashis an active sessionhistory. it only captures data about activesessions. ifa session becomes idl...

ashis an active sessionhistory.

it only captures data about activesessions.

ifa session becomes idle after taking a lock then details will not be recordedand so are not reported in any reports produced

ash是对active状态的session的采样(每秒采样).也就是说:

oracle10g中,引入了awr和ash采样机制,有一个视图gv$active_session_history会每秒钟将所有节点的active session采样一次,

而dba_hist_active_sess_history则会将gv$active_session_history里的数据每10秒采样一次并持久化保存

https://blogs.oracle.com/database4cn/dbahistactivesesshistory