M

managed targets

Entities that can be monitored and managed within the Oracle Management Framework. These entities include databases, application servers, web servers, applications, and Oracle agents such as the Oracle Net listener and Connection Manager. See also Oracle Connection Manager.

mean time to recovery (MTTR)

The average amount of time it takes to recover the database and make it available after an instance failure occurs.

media failure

A failure in which one or more database files is damaged. Media failure applies to control files, redo log files, tempfiles and datafiles.

metadata

Data that describes data. Metadata includes table definitions, stored PL/SQL program code, and privileges, but not the information found in tables.

metric

A measurement that is collected and stored in the AWR (Automatic Workload Recovery) repository. See also Automatic Workload Recovery (AWR).

middleware

Software and hardware that sits between a client and the Oracle server. Middleware can provide a variety of functions such as load balancing, security, and application-specific business logic processing.

MTTR

See mean time to recovery (MTTR).

multiplexing

Creating multiple copies of a redo log file or control file in different locations so that the loss of one copy does not significantly affect your ability to recover a database.