Oracle Audio Technologies B10508-01 ユーザーズマニュアル

Starter Database Contents

Oracle9i Installation Guide Release 2 (9.2.0.2) for HP Alpha OpenVMS

The starter database contains three control files

.  

These files are located in the 

ora_root:[oradata.<

>]

 directory

.  

The files 

control01.ctl

, 

control02.ctl

, and 

control03.ctl

 are automatically included in the Custom 

database

.  

Oracle Corporation recommends that you keep at least three control files 

(on separate physical drives) for each database and set the CONTROL_FILES 
initialization parameter to list each control file

.  

 describes the database 

control files.

Rollback segments record the old values of data that are changed by each 
transaction, whether or not the transaction has been committed.  Every database 
contains one or more rollback segments.  Use rollback segments to provide read 
consistency, to roll back transactions, and to recover the database.  The rollback 
segments of the starter database are as follows:

■

Rollback segment SYSTEM is contained in tablespace SYS and is used by SYS.

■

Rollback segments _SYSSMU1$ through _SYSSMU10$ are a pool of rollback 
segments that any instance can use if it requires a rollback segment.  They are 
contained in tablespace UNDOTBS<n> and are used by PUBLIC.

The data dictionary is a protected collection of tables and views containing 
reference information on the database, its structure, and its users

.  

The data that is 

stored in the dictionary includes the following:

control01.ctl

control02.ctl

control03.ctl

A control file is an administrative file

.  

Oracle9i requires a 

control file to start and run the database

.  

The control file 

records the physical structure of the database

.  

For example, a 

control file contains the database name, and the names and 
locations of the database data files and redo log files.

Oracle9i Database Administrator’s Guide for more 

information on setting this initialization parameter value.