Monday, April 16, 2007

Oracle9i DBA -- Database: Fundamentals I (6)

Maintaining the Control File


  • Multiplexing the control file using spfile step

1. Alter the spfile

2. Showdown normal

3. Create additional control files

4. Start the database

  • Multiplexing the Control File Using init.ora(pfile)

1. Shutdown normal

2. create additional control files

3. Add the new control file name to init.ora

4. Start the database

  • V$PARAMETER lists the status and location of all parameters (eg. Control files names)

V$CONTROLFILE_RECORD_SECTION provides information about control file record sections.

V$CONTROLFILE provides information about the name and status of all control files.


  • The database has to be in the NOMOUNT state to create the control file.
  • The recommended way is to have 3 control file copies on separate disks to provide fault tolerance. The maximum level of multiplexing control files is 8 , minimum is 2. But in OMF only up to 5
  • The Redo Log files and Control files creation share the common parameter DB_CREATE_ONLINE_LOG_DEST_n parameter through OMF, while datafiles use DB_CREATE_FILE_DEST.
  • DB_CREATE_FILE_DEST sets the default location for datafile, control file, and online log creation.
  • When available control file is failed, Recover the database using SQL>STARTUP RECOVER or RMAN>RECOVERY DATABASE

Read more!

No comments: