6
Copyright © Oracle Corporation, 2002. All rights reserved.
Maintaining the Control File
6-2 Copyright © Oracle Corporation, 2002. All rights reserved.
Objectives
After completing this lesson, you should be able to do
the following:
•Explain the uses of the control file
•List the contents of the control file
•Multiplex and manage the control file
•Manage the control file with Oracle Managed Files
(OMF)
•Obtain control file information
6-3 Copyright © Oracle Corporation, 2002. All rights reserved.
Control File
•A small binary file
•Defines current state of physical database
•Maintains integrity of database
•Required:
–At MOUNT state during database start up
–To operate the database
•Linked to a single database
•Loss may require recovery
•Sized initially by
CREATE DATABASE
Control
files
Database
6-4 Copyright © Oracle Corporation, 2002. All rights reserved.
6-5 Copyright © Oracle Corporation, 2002. All rights reserved.
Control File Contents
A control file contains the following entries:
•Database name and identifier
•Time stamp 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
•Backup information