在Oracle 11g 以前，我们可以从spfile来创建pfile，或者利用pfile来创建spfile。 在Oracle 11g中，在管理spfile方面得到增强，可以从memory来创建pfile和spfile。
语法如下：
CREATE PFILE [= 'pfile_name' ]
FROM { { SPFILE [= 'spfile_name'] } | MEMORY } ;
CREATE SPFILE [= 'spfile_name' ]
FROM { { PFILE [= 'pfile_name' ] } | MEMORY } ;
示例：
[15:43 oracle@dave /u01/backup]$ora si
SQL*Plus: Release 11.2.0.3.0 Production onFri Oct 12 15:43:22 2012
Copyright (c) 1982, 2011, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Enterprise EditionRelease 11.2.0.3.0 - 64bit Production
With the Partitioning, OLAP, Data Miningand Real Application Testing options
SQL> create pfile from memory;
File created.
SQL> create spfile from memory;
create spfile from memory
*
ERROR at line 1:
ORA-32002: cannot createSPFILE already being used by the instance
--对于open 状态的实例，不能从memory创建spfile。
SQL> startup mount force;
ORACLE instance started.
Total System Global Area 730714112 bytes
Fixed Size 2231952 bytes
Variable Size 285213040 bytes
Database Buffers 419430400 bytes
Redo Buffers 23838720 bytes
Database mounted.
SQL> select open_mode from v$database;
OPEN_MODE
--------------------
MOUNTED
SQL> create spfile from memory;
create spfile from memory
*
ERROR at line 1:
ORA-32002: cannot createSPFILE already being used by the instance
--mount 状态也不可以使用
SQL> startup nomount force;
ORACLE instance started.
Total System Global Area 730714112 bytes
Fixed Size 2231952 bytes
Variable Size 285213040 bytes
Database Buffers 419430400 bytes
Redo Buffers 23838720 bytes
SQL> create spfile from memory;
create spfile from memory
*
ERROR at line 1:
ORA-32002: cannot createSPFILE already being used by the instance
--nomount 状态也不可以
SQL> shutdown abort;
ORACLE instance shut down.
SQL> create spfile from memory;
create spfile from memory
*
ERROR at line 1:
ORA-00922: missing or invalid option
--数据库关闭后，语法不可以用。
我们用pfile启动数据库，在来创建spfile：
SQL> startuppfile='/u01/app/oracle/product/11.2.0/db_1/dbs/initdave.ora'
ORACLE instance started.
Total System Global Area 730714112 bytes
Fixed Size 2231952 bytes
Variable Size 285213040 bytes
Database Buffers 419430400 bytes
Redo Buffers 23838720 bytes
Database mounted.
Database opened.
SQL> create spfile from memory;
File created.
--这次创建成功。
注意：
（1）如果是RAC 环境，那么生成的脚本会包含所有节点的参数。
（2）执行这个命令需要使用sysdba或sysoper角色来执行。