Automatic Memory Management

Oracle Database 11g XE uses the Automatic Memory Management (AMM) feature that simplifies SGA and PGA memory management significantly. The MEMORY_TARGET initialization parameter is used to automatically manage memory needs. When the MEMORY_TARGET parameter is set, Oracle Database 11g XE automatically sizes various memory components such as database buffer cache, Java pool, shared pool, streams pool, large pool, and process global area.

You cannot disable AMM in Oracle Database XE configuration. The MEMORY_TARGET parameter by default is set to 1 GB when you install Oracle Database XE. Oracle Database 11g XE includes four new views to support automatic memory management:

• V$MEMORY_CURRENT_RESIZE_OPS

• V$MEMORY_DYNAMIC_COMPONENTS

• V$MEMORY_RESIZE_OPS

• V$MEMORY_TARGET_ADVICE

The amount of memory allocated to each dynamic component is displayed using the V$MEMORY_DYNAMIC_COMPONENTS view, as shown in the following command:

SQL> SELECT * FROM v$memory_dynamic_components...