设置数据库自动内存管理主要是设置两个参数：
如果这两个参数设置为0说明数据库内存采用手动管理，反之则为自动管理。
SQL> startup nomount
ORA-00838: Specified value of MEMORY_TARGET is too small, needs to be at least 6384M
SQL> create pfile ='/home/oracle/initora11g.ora' from spfile;
File created.
创建pfile文件，然后修改pfile文件设置这两个参数大小为7G。
[oracle@TestServer dbhome_1]$ vi /home/oracle/initora11g.ora
atsdb.__db_cache_size=16777216
atsdb.__java_pool_size=16777216
atsdb.__large_pool_size=16777216
atsdb.__oracle_base='/opt/app/oracle'#ORACLE_BASE set from environment
atsdb.__pga_aggregate_target=5083496448
atsdb.__sga_target=1610612736
atsdb.__shared_io_pool_size=0
atsdb.__shared_pool_size=1526726656
atsdb.__streams_pool_size=16777216
*.audit_file_dest='/opt/app/oracle/admin/atsdb/adump'
*.audit_trail='db'
*.compatible='11.2.0.0.0'
*.control_files='/opt/app/oracle/oradata/atsdb/control01.ctl','/opt/app/oracle/flash_recovery_area/atsdb/control02.ctl'
*.db_block_size=8192
*.db_domain=''
*.db_name='atsdb'
*.db_recovery_file_dest='/opt/app/oracle/flash_recovery_area'
*.db_recovery_file_dest_size=4070572032
*.diagnostic_dest='/opt/app/oracle'
*.dispatchers='(PROTOCOL=TCP) (SERVICE=atsdbXDB)'
*.global_names=FALSE
*.memory_max_target=7610612736
*.memory_target=7610612736
*.open_cursors=300
*.pga_aggregate_target=5078253568
*.processes=3000
*.remote_login_passwordfile='EXCLUSIVE'
*.sessions=3555
*.sga_target=1610612736
*.undo_tablespace='UNDOTBS1'
修改完成之后从pfile启动数据库：
SQL>='/home/oracle
ORACLE instance started.
Total System Global Area 7616245760 bytes
Fixed Size 2214496 bytes
Variable Size 6979323296 bytes
Database Buffers 603979776 bytes
Redo Buffers 30728192 bytes
Database mounted.
Database opened.
SQL> create spfile from pfile='/home/oracle/initora11g.ora';
File created.
SQL> show parameter memory
NAME TYPE
------------------------------------ ----------------------
VALUE
------------------------------
hi_shared_memory_address integer
0
memory_max_target big integer
7296M
memory_target big integer
7296M
shared_memory_address integer
0
SQL>
成功。
