Oracle Memory Management

--Memory allocation
When you build a library, you can allocate system memory 50%-80% to Oracle and later adjust to your business.
SGA, PGA distribution ratio:
Oltp:sga%80, PGA%20
Olap:sga%50, PGA%50
Mixed: SGA%60, PGA%40

--SGA Automatic Management
The Statistics_level value is set to typical or all to start the SGA Auto-management.
A total value for the given sga_target.

--SGA Manual Management
Set the sga_target=0 to set the associated component size:
Java_pool_size
Large_pool_size
Shared_pool_size
Streams_pool_size
Db_cache_size
Log_buffer--seemingly cannot be set directly, to use pfile settings

Sql> alter system set sga_target=0 Scope=spfile;

System altered.

Sql> alter system set JAVA_POOL_SIZE=4M Scope=spfile;

System altered.

Sql> alter system set LARGE_POOL_SIZE=4M Scope=spfile;

System altered.

Sql> alter system set SHARED_POOL_SIZE=136M Scope=spfile;

System altered.

Sql> alter system set DB_CACHE_SIZE=352M Scope=spfile;

System altered.

Close and restart the database

--PGA Automatic Management
Enable PGA Auto-management when the Workarea_size_policy value is set to Auto
A total value for the given Pga_aggregate_target

Oracle 11g two parameters
Memory_target User automatic memory management (SGA and PGA)
Memory_max_size a target value for automatic memory management, which may actually exceed this value

Oracle Memory Management