oracle resetlogs和noresetlogs 创建控制文件区别
一：注意事项：
1 指定reuse
表明被初始化参数CONTROL_FILES 识别的控制文件能够被覆盖使用。如果忽略该参数，任何已经存在的控制文件被数据库检测到，则返回一个报错。
2 指定SET DATABASE
表明要更改数据库的名字，名字长度能达到8个字节。除此之外，你必须指定resetlogs语句，如果你想重新命名数据库的名字，并保留已经存在的日志文件，则创建控制文件语句执行后
使用alter database recover using bakcup controlfile 语句执行一个完全数据库恢复。
3 指定resetlogs
indicate 忽略日志文件内容，或者日志文件不存在。
指定datafile
除了只读表空间的文件（可以之后添加）和临时表空间的数据文件，列出所有数据文件，就算这些文件需要进行恢复。
4 ARCHIVELOG | NOARCHIVELOG
如果忽略了ARCHIVELOG | NOARCHIVELOG oracle默认采用非归档模式。
二实验步骤：
1 以noresetlogs方式创建控制文件，控制文件内容
[oracle@oracle backup]$ cat control.sql
STARTUP NOMOUNT
CREATE CONTROLFILE REUSE DATABASE "CRM" NORESETLOGS ARCHIVELOG
MAXLOGFILES 16
MAXLOGMEMBERS 3
MAXDATAFILES 100
MAXINSTANCES 8
MAXLOGHISTORY 292
LOGFILE
GROUP 1 '/oracle/CRM/redo01.log' SIZE 200M BLOCKSIZE 512,
GROUP 2 '/oracle/CRM/redo02.log' SIZE 200M BLOCKSIZE 512,
GROUP 3 '/oracle/CRM/redo03.log' SIZE 200M BLOCKSIZE 512,
GROUP 4 '/oracle/CRM/redo02.dbf' SIZE 200M BLOCKSIZE 512
DATAFILE
'/oracle/CRM/system01.dbf',
'/oracle/CRM/sysaux01.dbf',
'/oracle/CRM/undotbs01.dbf',
'/backup/users01.dbf',
'/oracle/CRM/pos.dbf',
'/oracle/CRM/erp.dbf',
'/oracle/CRM/user01.dbf',
'/oracle/CRM/undotbs02.dbf'
CHARACTER SET ZHS16GBK
;
2 以resetlogs方式创建控制文件，控制文件内容
cat control.sql
STARTUP NOMOUNT
CREATE CONTROLFILE REUSE DATABASE "CRM" RESETLOGS ARCHIVELOG
MAXLOGFILES 16
MAXLOGMEMBERS 3
MAXDATAFILES 100
MAXINSTANCES 8
MAXLOGHISTORY 292
LOGFILE
GROUP 1 '/oracle/CRM/redo01.log' SIZE 200M BLOCKSIZE 512,
GROUP 2 '/oracle/CRM/redo02.log' SIZE 200M BLOCKSIZE 512,
GROUP 3 '/oracle/CRM/redo03.log' SIZE 200M BLOCKSIZE 512,
GROUP 4 '/oracle/CRM/redo02.dbf' SIZE 200M BLOCKSIZE 512
DATAFILE
'/oracle/CRM/system01.dbf',
'/oracle/CRM/sysaux01.dbf',
'/oracle/CRM/undotbs01.dbf',
'/backup/users01.dbf',
'/oracle/CRM/pos.dbf',
'/oracle/CRM/erp.dbf',
'/oracle/CRM/user01.dbf',
'/oracle/CRM/undotbs02.dbf'
CHARACTER SET ZHS16GBK
;
3 恢复过程
noresetlogs方式
SQL> @/backup/control.sql
ORACLE instance started.
Total System Global Area 1252663296 bytes
Fixed Size 2226072 bytes
Variable Size 1006635112 bytes
Database Buffers 234881024 bytes
Redo Buffers 8921088 bytes
Control file created.
SQL> select open_mode from v$database;
OPEN_MODE
--------------------
MOUNTED
SQL> recover database;
ORA-00283: recovery session canceled due to errors
ORA-00264: no recovery required
SQL> alter database open;
Database altered.
resetlogs方式
SQL> @/backup/control.sql
ORACLE instance started.
Total System Global Area 1252663296 bytes
Fixed Size 2226072 bytes
Variable Size 1006635112 bytes
Database Buffers 234881024 bytes
Redo Buffers 8921088 bytes
Control file created.
SQL> recover database;
ORA-00283: recovery session canceled due to errors
ORA-01610: recovery using the BACKUP CONTROLFILE option must be done
SQL> recover database using backup controlfile;
ORA-00279: change 2526007 generated at 08/26/2012 01:13:10 needed for thread 1
ORA-00289: suggestion : /oracle/archive/1_8_791790817.dbf
ORA-00280: change 2526007 for thread 1 is in sequence #8
Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
auto
ORA-00308: cannot open archived log '/oracle/archive/1_8_791790817.dbf'
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3
ORA-00308: cannot open archived log '/oracle/archive/1_8_791790817.dbf'
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3
SQL> recover database using backup controlfile until cancel;
ORA-00279: change 2526007 generated at 08/26/2012 01:13:10 needed for thread 1
ORA-00289: suggestion : /oracle/archive/1_8_791790817.dbf
ORA-00280: change 2526007 for thread 1 is in sequence #8
Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
cancel
Media recovery cancelled.
SQL> alter database open resetlogs;
Database altered.
SQL> select open_mode from v$database;
OPEN_MODE
--------------------
READ WRITE