how to set the memory target parameter in oracle 11g

How to set the memory target parameter in oracle 11g

SQL> show parameter memory

NAME                                 TYPE        VALUE

------------------------------------ ----------- ------------------------------

hi_shared_memory_address             integer     0

memory_max_target                    big integer 0

memory_target                        big integer 0

shared_memory_address                integer     0

SQL> ALTER SYSTEM SET MEMORY_MAX_TARGET=3G SCOPE=SPFILE;

System altered.

SQL> ALTER SYSTEM SET MEMORY_TARGET=2G SCOPE=SPFILE;

System altered.

SQL> ALTER SYSTEM SET PGA_AGGREGATE_TARGET=0 SCOPE=SPFILE;

System altered.

SQL> ALTER SYSTEM SET SGA_TARGET=0 SCOPE=SPFILE;

System altered.

SQL> SHUTDOWN IMMEDIATE;

Database closed.

Database dismounted.

ORACLE instance shut down.

SQL> STARTUP;

ORACLE instance started.

Total System Global Area 3207790592 bytes

Fixed Size                  2092920 bytes

Variable Size            2248151176 bytes

Database Buffers          939524096 bytes

Redo Buffers               18022400 bytes

Database mounted.

Database opened.

SQL> show parameter memory

NAME                                 TYPE        VALUE

------------------------------------ ----------- ------------------------------

hi_shared_memory_address              integer     0

memory_max_target                    big integer  3G

memory_target                            big integer  2G

shared_memory_address                 integer     0

SQL>