Process Monitor Process (PMON) (121)

The process monitor (PMON) performs process recovery when a user process fails.
PMON is responsible for cleaning up the database buffer cache and freeing resources
that the user process was using. For example, it resets the status of the active
transaction table, releases locks, and removes the process ID from the list of active
processes.
PMON periodically checks the status of dispatcher and server processes, and restarts
any that have stopped running (but not any that Oracle has terminated intentionally).
PMON also registers information about the instance and dispatcher processes with the
network listener.
Like SMON, PMON checks regularly to see whether it is needed and can be called if
another process detects the need for it.

程式監視程式
主要用來
1. 程式恢復
2. 整理資料庫快取記憶體和空暇的資源(鎖 , 活動的事務列表)

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