Oracle10G:ash的采样机制
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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:
在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