MEMORY_TARGET

Property	Description
Parameter type	Big integer
Syntax	`MEMORY_TARGET =` `integer` `[K \| M \| G]`
Default value	`0` (SGA autotuning is disabled for `DEFERRED` mode autotuning requests, but allowed for `IMMEDIATE` mode autotuning requests)
Modifiable	`ALTER SYSTEM`
Range of values	152 MB to `MEMORY_MAX_TARGET`
Basic	No

MEMORY_TARGET specifies the Oracle system-wide usable memory. The database tunes memory to the MEMORY_TARGET value, reducing or enlarging the SGA and PGA as needed.

MEMORY_TARGET should be set higher than or equal to the sum of the current sizes of the SGA and PGA.

In a text-based initialization parameter file, if you omit MEMORY_MAX_TARGET and include a value for MEMORY_TARGET, then the database automatically sets MEMORY_MAX_TARGET to the value of MEMORY_TARGET. If you omit the line for MEMORY_TARGET and include a value for MEMORY_MAX_TARGET, the MEMORY_TARGET parameter defaults to zero. After startup, you can then dynamically change MEMORY_TARGET to a nonzero value, provided that it does not exceed the value of MEMORY_MAX_TARGET.

Total memory usage can grow beyond the value of MEMORY_TARGET. For example, memory is allocated to PL/SQL tables and varrays regardless of the value of MEMORY_TARGET as long as memory is available at the operating system level.

In the Default value field, IMMEDIATE mode autotuning requests are necessary to avoid ORA-04031 errors. The DEFERRED and IMMEDIATE modes are reflected in the OPER_MODE column of the V$MEMORY_RESIZE_OPS view.

Note:

The default value of SGA_MAX_SIZE depends on the values of MEMORY_TARGET and MEMORY_MAX_TARGET.