M

Manageability Monitor (MMON) process

The process responsible for a host of tasks, including invoking ADDM after each snapshot collection, snapshot retention and purging, and ASH purging (under normal circumstances). When purging ASH, MMON also filters the data and stores a portion of it in the AWR. See also Active Session History; Automatic Database Diagnostic Monitor.

Manageability Monitor Light (MMNL) process

The process responsible for purging the ASH when it fills before the scheduled MMON purge takes place. Like the MMON process, MMNL filters the data in the ASH before purging and stores a portion of it in the AWR. See also Active Session History; Automatic Workload Repository.

manual channel allocation

A type of channel allocation that is performed any time you issue the command ALLOCATE CHANNEL. The manual command for allocating a channel is ALLOCATE CHANNEL channel_name TYPE DISK.

manually sized components

SGA memory components that are not dynamically sized by ASMM. Instead, they are sized according to their associated initialization parameter settings. These include the streams pool, the keep and recycle caches, and a few other miscellaneous components.

mapping priorities

A method used to resolve mapping rule conflicts. When a user session maps to more than one resource consumer group, mapping priorities are used to make the final determination.

MAX_DUMP_FILE_SIZE

An initialization parameter used to define the maximum size that a trace file can reach.

media management layer (MML)

An API that interfaces Recovery Manager (RMAN) with different hardware vendors' tape devices.

mirrored redo logs

At least one additional log member per log group. Also referred to as multiplexed redo logs.

MML

See media management layer.

MMNL

See Manageability Monitor Light process.

MMON

See Manageability Monitor process.

multiplexed redo logs

See mirrored redo logs.

multiplexing

A process by which multiple database files are read simultaneously and all of the blocks are written to the same RMAN backup set.