Oracle ORACLE9I B10508-01, Руководство по установке, Страница: 101 / 186

Starter Database Contents
Post-Installation 5-25
Locating the Initialization Parameter File
The database initialization parameter file (
init.ora
) is generated when a database
is created. The
init.ora
file is used to bring up the instance and to create the
database and the data dictionary. When the database is complete, the instance is
shutdown, and the
init.ora
file is saved to
ora_root:[dbs]init<SID>.ora
. The logical, ORA_PARAMS, points to
ora_root:[dbs]init<SID>.ora
.
The
init.ora
file is a text file that contains a list of preconfigured instance
configuration parameters and that must exist for an instance to start
.
No edits are
required to this file in order to use the starter database.
Locating Redo Log Files
The starter database and the custom database each contain three redo log files that
are located in the
ora_root:[oradata.<db_name>]
directory
.
Table 5–3
describes the redo log files.
See Also:
Oracle9i Database Administrator’s Guide and Oracle9i
Database Reference for more information on database-specific
initialization parameters and their default values.
Table 5–3 Redo Log files
Redolog Files Disk Size Description
redo01.rdo
redo02.rdo
redo03.rdo
100 MB
100 MB
100 MB
Redo log files hold a record of all changes
that are made to data in the database
buffer cache. If an instance failure occurs,
then Oracle9
i uses the redo log files to
recover the modified data in memory.
Oracle9 i uses redo log files in a cyclical
fashion. For example, if three files
constitute the online redo log, then
Oracle9
i fills the first file, then fills the
second file, and then fills the third file. In
the next cycle, it reuses and fills the first
file, the second file, and so on.
See Also:
Oracle9i Backup and Recovery Concepts for more
information on redo log files.