What Is Mmon in Oracle

MMON (Manageability Monitor) is a background process that gathers memory statistics (snapshots) and stores this information in the AWR (automatic workload repository). MMON is also responsible for issuing alerts for metrics that exceed their thresholds. This process was introduced in Oracle 10g.

How do I start MMON?

1. Grant restricted session to public: This grant is required to avoid any impact on the sessions connecting to database. …
2. Enable and disable restricted sessions. …
3. Revoke the restricted session: revoke restricted session from public;
4. Check MMON process; ps -ef | grep mmon.

What is MMNL process Oracle?

MMNL gathers session statistics (such as the user ID, state, the machine, and the SQL it is executing) and stores them in the Active Session History (ASH) buffer. … This process will flush the ASH buffer to AWR tables when the buffer is full or a snapshot is taken.