db_create_file_dest

<span><span>RAC中。将db_create_file_dest改动为本地路径，在创建表空间指定ASM磁盘组的时候还能够直接'+DATA'么？</span></span>

1.查看參数设置
db_create_file_dest                  string      +DATA
2.改动并查看參数设置

SQL> alter system set db_create_file_dest='/u02' scope=both;

System altered.

SQL> show parameter db_create

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
db_create_file_dest                  string      /u02

3.模拟创建
+data下的datafile们：
ASMCMD [+data/orcl/datafile] > ls
SYSAUX.256.901333685
SYSTEM.265.901333685
UNDOTBS1.264.901333687
UNDOTBS2.266.901333943
USERS.257.901333687
tdb.dbf
tsys.dbf

在+data创建datafile
SQL> create tablespace dxmy datafile '+DATA' size 10m autoextend off;

Tablespace created.

+data下的datafile们：
ASMCMD [+data/orcl/datafile] > ls
DXMY.270.902737815     ---还是会自己主动创建
SYSAUX.256.901333685
SYSTEM.265.901333685
UNDOTBS1.264.901333687
UNDOTBS2.266.901333943
USERS.257.901333687
tdb.dbf
tsys.dbf

看来，这个是ASM自己主动管理的，跟数据库的这个參数没有关系。

那么。查了一下这个參数的作用：
DB_CREATE_FILE_DEST specifies the default location for Oracle-managed datafiles. This
location is also used as the default location for Oracle-managed control files and online
redo logs if none of the DB_CREATE_ONLINE_LOG_DEST_ n initialization parameters are
specified

OK，那就是OMF的路径了。