(Alex note) Maintaining the control file

uses of the control file
a. binary file
b. define current state of physical database
d. 只要data file 和redo log file 不丢，control file 还是有可能恢复的
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cd dbs
ls -al
strings spfile | more
# now we can found the control file path
cd /u01/oradata/wilson/    
strings control01.ctl | more
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conents of control file
Database name and identifier
Timestamp of database creation
Tablespace names
Names and locations of data files and online redo log files
current online redo log file sequence number
checkpoint information
begin and end of undo segments
Redo log archive information
RMAN information


multiplex and manage control file
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Alter system set control files = '$HOME/oradata/u01/ctrl01.ctl','$HOME/oradata/u01/ctrl02.ctl' scope=spfile;
shutdown immediate
cp $HOME/oradata/u01/ctrl01.ctl $HOME/oradata/u01/ctrl02.ctl
startup
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manager control file with OFM (不建议使用)
location: DB_CREATE_ONLINE_LOG_FILE_n

obtain control file information
V$CONTROLFILE
V$PARAMETER
V$CONTROLFILE_RECORD_SECTION (list the content of the control file)
Show parameter control_files (the same as from V$PARAMETER)

Creating new control files
....
Backing up control files
....