重建控制文件时DBA需要知道，但是也许整个职业生涯都不会再生产系统上遇见。
首先强调，备份是最安全，快捷，有效的恢复方式，一个DBA，如果没有规划好有效的备份，终有一天，他会被噩梦惊醒。
梦醒之后，就是无奈的，繁杂的手工恢复。而且，恢复到什么程度，就要看天，看命，反正不能看自己了，因为没有备份，你已经将主动权完全交个别人。这里就记录一下controlfile的重建
在其他正常的数据库上创建controlfile trace
SQL> alter database backup controlfile to trace;
指定trace文件的生成路径
SQL> alter database backup controlfile to trace as '/tmp/controlfile.trc'; trace 文件路径在user_dump_dest下
SQL> show parameter user_dump_dest
NAME TYPE VALUE
-------------- ------ ------------------------------------------------
user_dump_dest string /home/Oracle/admin/R10105/udump/
After navigating to the directory locate the latest trace file by date/time by issuing: ls -ltr.
% cd /home/oracle/admin/R10105/udump/
% ls -ltr
一个完整的trace请参考附件
你可以修改trace文件的路径等具体参数值，并提取其中的创建脚本
STARTUP NOMOUNT
CREATE CONTROLFILE REUSE DATABASE "R10105" NORESETLOGS ARCHIVELOG
MAXLOGFILES 16
MAXLOGMEMBERS 3
MAXDATAFILES 100
MAXINSTANCES 8
MAXLOGHISTORY 454
LOGFILE
GROUP 1 '/opt/oracle/oradata/R10105/redo01.log' SIZE 10M,
GROUP 2 '/opt/oracle/oradata/R10105/redo02.log' SIZE 10M,
GROUP 3 '/opt/oracle/oradata/R10105/redo03.log' SIZE 10M
-- STANDBY LOGFILE
DATAFILE
'/opt/oracle/oradata/R10105/system01.dbf',
'/opt/oracle/oradata/R10105/undotbs01.dbf',
'/opt/oracle/oradata/R10105/sysaux01.dbf',
'/opt/oracle/oradata/R10105/users01.dbf',
'/opt/oracle/oradata/R10105/example01.dbf'
CHARACTER SET AL32UTF8
;
注册archivelog
-- ALTER DATABASE REGISTER LOGFILE '/home/oracle/flash_recovery_area/R10105/archivelog/2012_06_15/o1_mf_1_1_%u_.arc';
-- ALTER DATABASE REGISTER LOGFILE '/home/oracle/flash_recovery_area/R10105/archivelog/2012_06_15/o1_mf_1_1_%u_.arc';
-- Recovery is required if any of the datafiles are restored backups,
-- or if the last shutdown was not normal or immediate.
RECOVER DATABASE
-- All logs need archiving and a log switch is needed.
ALTER SYSTEM ARCHIVE LOG ALL;
-- Database can now be opened normally.
ALTER DATABASE OPEN;
-- Commands to add tempfiles to temporary tablespaces.
-- Online tempfiles have complete space information.
-- Other tempfiles may require adjustment.
ALTER TABLESPACE TEMP ADD TEMPFILE '/opt/oracle/oradata/R10105/temp01.dbf'
SIZE 20971520 REUSE AUTOEXTEND ON NEXT 655360 MAXSIZE 32767M;
-- End of tempfile additions.
--
其实重建控制文件，就是相当于手动重新建库，把现有的数据库资源，逐一添加到controlfile中，最后注册目前的archivelog文件。
同时，重建controlfile分为NORESETLOGS和RESETLOGS两种，根据需求选择相应的脚本。
最后的最后，这一切，都是噩梦，还是做好有效备份，有备无患，才是王道！！