SQL> alter system set sga_max_size=2048M scope=spfile;
alter system set sga_max_size=2048M scope=spfile
*
ERROR at line 1:
ORA-32001: write to SPFILE requested but no SPFILE specified at startup
SQL> show parameter spfile;
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
spfile string
SQL> create spfile from pfile;
File created.
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup;
ORACLE instance started.
Total System Global Area 1068937216 bytes
Fixed Size 2166536 bytes
Variable Size 427819256 bytes
Database Buffers 624951296 bytes
Redo Buffers 14000128 bytes
Database mounted.
Database opened.
SQL> alter system set sga_max_size=2048M scope=spfile;
System altered.
SQL> alter system set sga_target=2048M scope=spfile;
System altered.
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup;
ORACLE instance started.
Total System Global Area 2137886720 bytes
Fixed Size 2161400 bytes
Variable Size 469763336 bytes
Database Buffers 1644167168 bytes
Redo Buffers 21794816 bytes
Database mounted.
Database opened.
SQL> show parameter sga;
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
lock_sga boolean FALSE
pre_page_sga boolean FALSE
sga_max_size big integer 2G
sga_target big integer 2G