What is Pmon and Smon?

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What is Pmon and Smon?

PMON and SMON are two required background processes. PMON is the Process Monitor which is responsible for recovering processes when the user process fails. PMON does the process cleanup. SMON is the System Monitor which is responsible for recovering the system after a failure.

What is Smon process?

SMON (System MONitor) is an Oracle background process created when you start a database instance. The SMON process performs instance recovery, cleans up after dirty shutdowns and coalesces adjacent free extents into larger free extents. SMON wakes up every 5 minutes to perform housekeeping activities.

What is Pmon in DBMS?

Process Monitor Process (PMON) 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.

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What is Pmon process in Oracle?

PMON (Process MONitor) is an Oracle background process created when you start a database instance. The PMON process will free up resources if a user process fails (eg. release database locks). PMON normally wakes up every 3 seconds to perform its housekeeping activities. PMON must always be running for an instance.

What is MMON process 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.

What is the purpose of Ckpt?

CKPT (Oracle Checkpoint Process) is an Oracle background process that timestamps all datafiles and control files to indicate that a checkpoint has occurred. The “DBWR checkpoints” statistic (v$sysstat) indicates the number of checkpoint requests completed.

Which tasks are accomplished by the Smon process?

SMON is the System Monitor and, among other things, performs instance recovery, cleans up the database transactions, and tidies up space utilization.

Which of the following is a function of Smon in Oracle database?

– The SMON background process performs all system monitoring functions on the oracle database. – Each time oracle is re-started, SMON performs a warm start and makes sure that the transactions that were left incomplete at the last shut down are recovered.

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Which of the following tasks does Smon background process?

The background processes each perform a specific set of tasks for the database. For example: SMON is the System Monitor and, among other things, performs instance recovery, cleans up the database transactions, and tidies up space utilization.

What is Pmon in semiconductor?

The process monitor (PMON) monitors the other background processes and performs process recovery when a server or dispatcher process terminates abnormally.

What is Ckpt in Oracle database?

From Oracle FAQ. CKPT (Oracle Checkpoint Process) is an Oracle background process that timestamps all datafiles and control files to indicate that a checkpoint has occurred. The “DBWR checkpoints” statistic (v$sysstat) indicates the number of checkpoint requests completed.

How do I start MMON?

Follow below steps to restart the MMON process:

  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.
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What is the difference between SMON and PMON?

* SMON – System Monitor process recovers after instance failure and monitors temporary segments and extents. SMON in a non-failed instance can also perform failed instance recovery for other failed RAC instance. * PMON – Process Monitor process recovers failed process resources.

What is the PMON process in Oracle?

PMON (Process MONitor) is an Oracle background process created when you start a database instance. The PMON process will free up resources if a user process fails (eg. release database locks).

What is SMON (system monitor)?

SMON (System Monitor): It is an important process responsible for recovering Oracle Instance. If this process does not work, the database is down. This process ensures that the instance to open consistently, during the database opening using the online redo log files when the Oracle database is closed inconsistently.

What does PMON stand for?

PMON (Process MONitor) is an Oracle background process created when you start a database instance. The PMON process will free up resources if a user process fails (eg.