如何獲取oracledbid
1.查詢v$database獲得
由於DBID在控制文件和數據文件中都存在記錄,所以如果能夠mount數據庫就可以查詢v$database視圖獲得.
SQL> alter database mount;
Database altered.
SQL> select dbid from v$database;
DBID
----------
1363251591
2.在nomount狀態時
如果數據庫配置了自動控制文件備份(Oracle9i),並且名稱是缺省的,那麼我們可以從自動備份文件獲得DBID.
[oracle@jumper dbs]$ cd $ORACLE_HOME/dbs
[oracle@jumper dbs]$ ll c-*
-rw-r----- 1 oracle dba 3375104 Dec 21 11:13 c-1363251591-20051221-00
-rw-r----- 1 oracle dba 3358720 Jan 21 14:03 c-1363251591-20060121-00
-rw-r----- 1 oracle dba 3358720 Jan 21 14:08 c-1363251591-20060121-01
這裡的1363251591就是DBID。在10g中，使用Flash Recovery Area，則沒有這個命名規則。
3.從自動備份中恢復
需要或缺DBID進行恢復通常是因為丟失了所有的控制文件.在恢復時會遇到錯誤.
[oracle@jumper dbs]$ rman target /
Recovery Manager: Release 9.2.0.4.0 - Production
Copyright (c) 1995, 2002, Oracle Corporation. All rights reserved.
connected to target database: conner (not mounted)
RMAN> restore controlfile from autobackup;
Starting restore at 05-FEB-06
using target database controlfile instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=11 devtype=DISK
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of restore command at 02/05/2006 20:47:25
RMAN-06495: must explicitly specify DBID with SET DBID command
如果存在自動備份,我們通常可以直接恢復控制文件,mount數據庫之後就好辦了:
RMAN> restore controlfile from '/opt/oracle/product/9.2.0/dbs/c-1363251591-20051221-00';
Starting restore at 05-FEB-06
using channel ORA_DISK_1
channel ORA_DISK_1: restoring controlfile
channel ORA_DISK_1: restore complete
replicating controlfile
input filename=/opt/oracle/oradata/conner/control01.ctl
output filename=/opt/oracle/oradata/conner/control02.ctl
output filename=/opt/oracle/oradata/conner/control03.ctl
Finished restore at 05-FEB-06
4.直接從幸存的文件中讀取
由於DBID存在於數據文件及控制文件中,所以我們可以通過PL/SQL程序直接從文件中讀取:
SQL> select eygle.get_dbid('/opt/oracle/oradata/conner','user02.dbf') from dual;
EYGLE.GET_DBID('/OPT/ORACLE/OR
------------------------------
1363251591
SQL> select dbid from v$database;
DBID
----------
1363251591
其實更簡單的，用BBED就好了。
這種方法僅為測試興趣所致,不被推薦.
--
此處為eygle自定義的函數 （抽時間我會補上）
5、通過dump數據文件獲取dbid：
SYS@orcl> alter system dump datafile 'D:\APP\ADMINISTRATOR\ORADATA\ORCL\USERS01.DBF' block 1000;
系統已更改。
SYS@orcl> select tracefile from v$process where addr in (select paddr from v$session where sid in (select sid from v$mystat));
--查看trace文件：Db ID=1363251591
TRACEFILE
------------------------------------------------------------------------------
d:\app\administrator\diag\rdbms\orcl\orcl\trace\orcl_ora_6740.trc
Start dump data block from file D:\APP\ADMINISTRATOR\ORADATA\ORCL\USERS01.DBF minblk 0 maxblk -1
V10 STYLE FILE HEADER:
Compatibility Vsn = 186646528=0xb200000
Db ID=1363251591=0x51419187, Db Name='ORCL'
Activation ID=0=0x0
Control Seq=10579=0x2953, File size=1600=0x640
File Number=4, Blksiz=8192, File Type=3 DATA
Dump all the blocks in range:
...
-------------------------------
Dylan Presents.
