验证concepts中关于sga_target与sg…

os：OEL 5.8
version: oracle 11gR2


##对于sga_target大小不能大于sga_max_size
SQL> show parameter sga

NAME                TYPE    VALUE
------------------------------------ -----------------------------------------
lock_sga             boolean    FALSE
pre_page_sga             boolean    FALSE
sga_max_size             big integer 224M
sga_target             big integer 224M

SQL>  alter system setsga_target=225;
 alter system set sga_target=225
*
ERROR at line 1:
ORA-02097: parameter cannot be modified because specified value isinvalid
ORA-00827: could not shrink sga_target to specified value


SQL> alter system set sga_target=225m;
alter system set sga_target=225m
*
ERROR at line 1:
ORA-02097: parameter cannot be modified because specified value isinvalid
ORA-00823: Specified value of sga_target greater thansga_max_size

##在startup时，sga_target可以大于sga_max_size，并且sga_max_size自动会调整和sga_target一样大

SQL> show parameter sga

NAME                TYPE    VALUE
------------------------------------ -----------------------------------------
lock_sga             boolean    FALSE
pre_page_sga             boolean    FALSE
sga_max_size             big integer 224M
sga_target             big integer 224M

SQL> alter system set sga_target=225mscope=spfile;

System altered.

SQL> srartup force
SP2-0734: unknown command beginning "srartup fo..." - rest of lineignored.
SQL> startup force
ORACLE instance started.

Total System Global Area  238530560 bytes
Fixed Size         1335724 bytes
Variable Size        109055572 bytes
Database Buffers     125829120 bytes
Redo Buffers         2310144 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 228M
sga_target             big integer 228M
SQL>