SQL> startup nomount
ORA-00838: Specified value of MEMORY_TARGET is too small, needs to be at least 6384M
--这里之所以报错是我之前alter system set MEMORY_TARGET='1536M' scope='spfile';
因为之前系统分配给SGA的内存就这么大，我设置的参数绝对不能超过SGA，这也就是导致修改完参数重启数据库出错的原因。
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 startup pfile/initora11g.ora'
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.
可以看到数据库已经重新启动，因为刚才是在pfile中修改的参数，现在同步到spfile中：
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>
