Summary of Memory Management Methods

Table 18-1 summarizes the various memory management methods. If you do not enable automatic memory management, then you must separately configure one memory management method for the SGA and one for the PGA.

Note:

When automatic memory management is not enabled, the default method for the instance PGA is automatic PGA memory management.

Table 18-1 Memory Management Methods

Instance	SGA	PGA	Description	Initialization Parameters
Auto	n/a	n/a	The database tunes the size of the instance based on a single instance target size.	You set: Total memory target size for the database instance (`MEMORY_TARGET`) Optional maximum memory size for the database instance (`MEMORY_MAX_TARGET`)
n/a	Auto	Auto	The database automatically tunes the SGA based on an SGA target. The database automatically tunes the PGA based on a PGA target.	You set: SGA target size (`SGA_TARGET`) Optional SGA maximum size (`SGA_MAX_SIZE`) Instance PGA target size (`PGA_AGGREGATE_TARGET`)
n/a	Auto	Manual	The database automatically tunes the SGA based on an SGA target. You control the PGA manually, setting the maximum work area size for each type of SQL operator.	You set: SGA target size (`SGA_TARGET`) Optional SGA maximum size (`SGA_MAX_SIZE`) PGA work area parameters such as `SORT_AREA_SIZE`, `HASH_AREA_SIZE`, and `BITMAP_MERGE_AREA_SIZE`
n/a	Manual	Auto	You control the SGA manually by setting individual component sizes. The database automatically tunes the PGA based on a PGA target.	You set: Shared pool size (`SHARED_POOL_SIZE`) Buffer cache size (`DB_CACHE_SIZE`) Large pool size (`LARGE_POOL_SIZE`) Java pool size (`JAVA_POOL_SIZE`) Streams pool size (`STREAMS_POOL_SIZE`) Instance PGA target size (`PGA_AGGREGATE_TARGET`)
n/a	Manual	Manual	You must manually configure SGA component sizes. You control the PGA manually, setting the maximum work area size for each type of SQL operator.	You must manually configure SGA component sizes. You set: Shared pool size (`SHARED_POOL_SIZE`) Buffer cache size (`DB_CACHE_SIZE`) Large pool size (`LARGE_POOL_SIZE`) Java pool size (`JAVA_POOL_SIZE`) Streams pool size (`STREAMS_POOL_SIZE`) PGA work area parameters such as `SORT_AREA_SIZE`, `HASH_AREA_SIZE`, and `BITMAP_MERGE_AREA_SIZE`