Call now: 252-767-6166  
Oracle Training Oracle Support Development Oracle Apps

 E-mail Us
 Oracle Articles
New Oracle Articles

 Oracle Training
 Oracle Tips

 Oracle Forum
 Class Catalog

 Remote DBA
 Oracle Tuning
 Emergency 911
 RAC Support
 Apps Support
 Oracle Support

 SQL Tuning

 Oracle UNIX
 Oracle Linux
 Remote s
 Remote plans
 Application Server

 Oracle Forms
 Oracle Portal
 App Upgrades
 SQL Server
 Oracle Concepts
 Software Support

 Remote S


 Consulting Staff
 Consulting Prices
 Help Wanted!


 Oracle Posters
 Oracle Books

 Oracle Scripts

Don Burleson Blog 









Password File

Oracle RAC Cluster Tips by Burleson Consulting

This is an excerpt from the bestselling book Oracle Grid & Real Application Clusters.  To get immediate access to the code depot of working RAC scripts, buy it directly from the publisher and save more than 30%.

The password file is another important file which is shared by all the instances of the RAC database system. This file, which is stored in binary format, records all the authentication privileges granted to the users.  Privileges such as SYSDBA or SYSOPER are recorded in this file.  The password file is required for remote authentication for the users with SYSDBA or SYSOPER privileges. This file is located on the cluster file system and is accessible to all the nodes in the cluster.

Alert Log File and Trace Files

Each instance in the RAC database keeps writing to the alert log file and also produces trace files periodically. The Alert Log file contains all the messages the Oracle database kernel generates. Trace Files contain detailed information about a specific event or issue. These log and trace files help the administrators keep track of the database activity and also assist in troubleshooting.

The Alter Log File and Trace Files can be written either to a directory within a local file system or within the cluster file system.

Files for loading into External Tables

External Tables allow direct access of data located in the operating system level files by using the SQL interface within the database. It is a new way of reading and writing files into and out of the database. Data stored in operating system level files (ASCII filer) can be accessed as if they are some kind of table with rows and columns. The usual SQL interface can be used and even the joins can be constructed with data in the O/S file and logical database tables.

For all practical purposes, external tables act the same as the usual tables; however, the data is not stored with the Oracle Data Files. External Tables are a great way to load the data into a database and do data processing.

There is no restriction as to where the external table data file has to be located. In a RAC database system, it can be located on the local file system or on a cluster file system. For the sake of concurrent access, it becomes more meaningful to keep the external table file on a shared storage or cluster file system. This allows for transparent access to the external table so any instance in the RAC database should be able to read and write to it at the operating system level (ASCII). This is possible only if the external table file is located on a clustered file system.

Oracle Cluster Registry (OCR)

The OCR contains cluster and database configuration information for RAC and Cluster Ready Services (CRS) such as the cluster node list, cluster database instances to node mapping, and CRS application resource profiles.

The OCR is a shared file located in a cluster file system. When the Cluster File System is not in use, the OCR file can be located on a shared raw device in UNIX-based systems, or a shared logical partition in Windows environments. During the installation of Cluster Ready Services software, the Oracle Universal Installer (OUI) automatically initializes the OCR file by executing the srvconfig -init command.

If more than one database is created on the cluster, they all share the same Oracle cluster registry. If upgrading from Oracle9i Release 2, then the raw device that was used for the SRVM configuration repository can be used instead of creating this new logical volume.


This is an excerpt from the bestselling book Oracle Grid & Real Application Clusters, Rampant TechPress, by Mike Ault and Madhu Tumma.

You can buy it direct from the publisher for 30%-off and get instant access to the code depot of Oracle tuning scripts.


Oracle Training at Sea
oracle dba poster

Follow us on Twitter 
Oracle performance tuning software 
Oracle Linux poster


Burleson is the American Team

Note: This Oracle documentation was created as a support and Oracle training reference for use by our DBA performance tuning consulting professionals.  Feel free to ask questions on our Oracle forum.

Verify experience! Anyone considering using the services of an Oracle support expert should independently investigate their credentials and experience, and not rely on advertisements and self-proclaimed expertise. All legitimate Oracle experts publish their Oracle qualifications.

Errata?  Oracle technology is changing and we strive to update our BC Oracle support information.  If you find an error or have a suggestion for improving our content, we would appreciate your feedback.  Just  e-mail:  

and include the URL for the page.


Burleson Consulting

The Oracle of Database Support

Oracle Performance Tuning

Remote DBA Services


Copyright © 1996 -  2017

All rights reserved by Burleson

Oracle ® is the registered trademark of Oracle Corporation.

Remote Emergency Support provided by Conversational