五. 是否使用了spfile
判断是否使用了SPFILE，可以使用以下方法：
1．查询v$parameter动态视图，如果以下查询返回空值，那么你在使用pfile.
SQL> SELECT name,value FROM v$parameter WHERE name='spfile';
2．或者你可以使用SHOW命令来显示参数设置，如果以下结果value列返回空值，那么说明你在使用pfile:
SQL> SHOW PARAMETER spfile
3．查询v$spparameter视图
如果以下查询返回0值，表示你在使用pfile,否则表明你使用的是spfile:
SQL> SELECT COUNT(*) FROM v$spparameter WHERE value IS NOT NULL;
或者使用以下查询，如果true值返回非0值，那么说明我们使用的是spfile.
SQL> select isspecified, count(*) from v$spparameter group
2 by isspecified;
ISSPECIFIED COUNT(*)
------------ ----------
FALSE 226
TRUE 33
更为直接的：
SQL> select decode(count(*), 1, 'spfile', 'pfile' ) USED
2 from v$spparameter
3 where rownum=1 and isspecified='TRUE'
4 /
USED
------------
spfile
六. SPFILE的备份与恢复
下面我们来看一下这个过程:
a. 设置控制文件自动备份:
[oracle@jumper oracle]$ rman target /
Recovery Manager: Release 9.2.0.3.0 - Production
Copyright (c) 1995, 2002, Oracle Corporation. All rights reserved.
connected to target database: HSJF (DBID=1052178311)
RMAN> CONFIGURE CONTROLFILE AUTOBACKUP ON;
using target database controlfile instead of recovery catalog
old RMAN configuration parameters:
CONFIGURE CONTROLFILE AUTOBACKUP OFF;
new RMAN configuration parameters:
CONFIGURE CONTROLFILE AUTOBACKUP ON;
new RMAN configuration parameters are successfully stored
RMAN> exit
这个设置可以在数据库中通过如下方式查询得到:
[oracle@jumper bdump]$ sqlplus "/ as sysdba"
SQL> select * from v$rman_configuration;
CONF# NAME VALUE
---------- ------------------------- ----------
1 CONTROLFILE AUTOBACKUP ON
b. 记录数据库变化
SQL> create tablespace eygle datafile '/data1/oracle/oradata/eygle01.dbf' size 5M;
如果新创建一个表空间，这时候检查alert<sid>.log文件，你可以在其中发现这样的备份信息:
Sat Jan 17 00:55:57 2004Starting control autobackupControl autobackup written to DISK devicehandle '/opt/oracle/product/9.2.0/dbs/c-1052178311-20040117-00'Completed: create tablespace eygledatafile '/data1/oracle/oradata/eygle01.dbf’
如果使用rman进行备份，在提示中你可以看到如下信息:
RMAN> configure controlfile autobackup on;
old RMAN configuration parameters:
CONFIGURE CONTROLFILE AUTOBACKUP OFF;
new RMAN configuration parameters:
CONFIGURE CONTROLFILE AUTOBACKUP ON;
new RMAN configuration parameters are successfully stored
RMAN> run
2> {
3> allocate channel ch1 type disk format='e:\oracle\orabak\penny%t.arc';
4> backup archivelog all delete all input;
5> release channel ch1;
6> }
allocated channel: ch1
channel ch1: sid=13 devtype=DISK
Starting backup at 02-DEC-03
current log archived
channel ch1: starting archive log backupset
channel ch1: specifying archive log(s) in backup set
input archive log thread=1 sequence=63 recid=168 stamp=511712617
input archive log thread=1 sequence=64 recid=169 stamp=511712620
input archive log thread=1 sequence=65 recid=170 stamp=511712626
input archive log thread=1 sequence=66 recid=171 stamp=511712690
channel ch1: starting piece 1 at 02-DEC-03
channel ch1: finished piece 1 at 02-DEC-03
piece handle=E:\ORACLE\ORABAK\PENNY511712693.ARC comment=NONE
channel ch1: backup set complete, elapsed time: 00:00:03
channel ch1: deleting archive log(s)
archive log filename=E:\ORACLE\ORADATA\PENNY\ARCHIVE\1_63.DBF recid=168 stamp=511712617
archive log filename=E:\ORACLE\ORADATA\PENNY\ARCHIVE\1_64.DBF recid=169 stamp=511712620
archive log filename=E:\ORACLE\ORADATA\PENNY\ARCHIVE\1_65.DBF recid=170 stamp=511712626
archive log filename=E:\ORACLE\ORADATA\PENNY\ARCHIVE\1_66.DBF recid=171 stamp=511712690
Finished backup at 02-DEC-03
Starting Control File and SPFILE Autobackup at 02-DEC-03
piece handle=E:\ORACLE\ORA92\DATABASE\C-3627775766-20031202-01 comment=NONE
Finished Control File and SPFILE Autobackup at 02-DEC-03
released channel: ch1
我们简单看一下自动备份的控制文件及spfile文件的格式及命名规则:
c-IIIIIIIIII-YYYYMMDD-QQ
c ------------------------控制文件
IIIIIIIIII---------DBID
YYYYMMDD------------时间戳
QQ----------------------序号00-FF，16进制表示
c. 使用自动备份恢复spfile文件
[oracle@jumper bdump]$ rman target /
Recovery Manager: Release 9.2.0.3.0 - Production
Copyright (c) 1995, 2002, Oracle Corporation. All rights reserved.
connected to target database: HSJF (DBID=1052178311)
RMAN> restore spfile to '/tmp/spfileeygle.ora' from autobackup;
Starting restore at 17-JAN-04
using target database controlfile instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=18 devtype=DISK
channel ORA_DISK_1: looking for autobackup on day: 20040117
channel ORA_DISK_1: autobackup found: c-1052178311-20040117-01
channel ORA_DISK_1: SPFILE restore from autobackup complete
Finished restore at 17-JAN-04
RMAN> exit
Recovery Manager complete.
[oracle@jumper bdump]$ ls -l /tmp/spfileeygle.ora
-rw-r----- 1 oracle dba 3584 1月 17 09:34 /tmp/spfileeygle.ora
你同样可以通过这种方法恢复控制文件，示例如下:
[oracle@jumper bdump]$ rman target /
RMAN> restore controlfile to '/tmp/control01.ctl' from autobackup;
Starting restore at 17-JAN-04
using target database controlfile instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=10 devtype=DISK
channel ORA_DISK_1: looking for autobackup on day: 20040117
channel ORA_DISK_1: autobackup found: c-1052178311-20040117-02
channel ORA_DISK_1: controlfile restore from autobackup complete
Finished restore at 17-JAN-04
RMAN> exit
Recovery Manager complete.
[oracle@jumper bdump]$ ls -l /tmp/control*
-rw-r----- 1 oracle dba 1892352 1月 17 09:44 /tmp/control01.ctl
Oracle9i自动备份控制文件的功能给我们带来了极大的收益,通过自动备份,在数据库出现紧急状况的时候,你可能可以从这个自动备份中获得更
为有效及时的控制文件.
缺省的,这个自动备份功能是关闭的,你可以用我们上面提到的方法打开该功能.
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