SQL> show parameter open_cursors
NAME? TYPE? VALUE
------------------------------------ ----------- ------------------------------
open_cursors? integer? 400

我们只是修改参数文件，加上scope=spfile
SQL> alter system set open_cursors=300 scope=spfile;
System altered.

如果要查看参数的值，看当前session的
SQL> show parameter open_cursors

NAME? TYPE? VALUE
------------------------------------ ----------- ------------------------------
open_cursors? integer? 400

SQL> desc v$parameter
Name? Null?? Type
----------------------------------------- -------- ----------------------------
NUM? NUMBER
NAME? VARCHAR2(80)
TYPE? NUMBER
VALUE? VARCHAR2(4000)
DISPLAY_VALUE? VARCHAR2(4000)
ISDEFAULT? VARCHAR2(9)
ISSES_MODIFIABLE? VARCHAR2(5)
ISSYS_MODIFIABLE? VARCHAR2(9)
ISINSTANCE_MODIFIABLE? VARCHAR2(5)
ISMODIFIED? VARCHAR2(10)
ISADJUSTED? VARCHAR2(5)
ISDEPRECATED? VARCHAR2(5)
ISBASIC? VARCHAR2(5)
DESCRIPTION? VARCHAR2(255)
UPDATE_COMMENT? VARCHAR2(255)
HASH? NUMBER

SQL> select name,value from v$parameter where name='open_cursors';

NAME? VALUE
--------------- ---------------------------------------------
open_cursors? 400

如果想要看参数的修改后参数文件里的值
SQL> desc v$spparameter
Name? Null?? Type
----------------------------------------- -------- ----------------------------
SID? VARCHAR2(80)
NAME? VARCHAR2(80)
TYPE? VARCHAR2(11)
VALUE? VARCHAR2(255)
DISPLAY_VALUE? VARCHAR2(255)
ISSPECIFIED? VARCHAR2(6)
ORDINAL? NUMBER
UPDATE_COMMENT? VARCHAR2(255)

SQL> col name for a15
SQL> col value for a45

SQL> select name,value from v$spparameter where name='open_cursors';

NAME? VALUE
--------------- ---------------------------------------------
open_cursors? 300

SQL> show spparameter open_cursors

SID? NAME? TYPE? VALUE
-------- ----------------------------- ----------- ----------------------------
*? open_cursors? integer? 300

显然，有了show spparameter ，操作更简单一些。