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 








Vertical vs. Horizontal scalability for Oracle

Oracle Database Tips by Donald Burleson

Best practices for scaling Oracle VLDB systems

For large Oracle databases, we often see multiple database servers being utilized, either the "server blade" approach of Oracle 10g Grid (horizontal scalability or "scale out"), the vertical scalability approach "scale up" where large servers are used, and a combination of both vertical and horizontal scalability solutions. 

Horizontal scaling for Oracle

This is called "horizontal scaling", or the "scale out" approach, whereby small server blades are genned-in to an Oracle RAC cluster over a high-speed interconnect.  Horizontal scaling requires Real Application Clusters and also provides the benefit of guaranteed continuous availability.

Vertical scaling for Oracle

We also see the "scale up" approach (the vertically scalable architecture) whereby server resources (CPU, RAM, Disk) can be added into a single, monolithic server.  Examples include the HP Superdome (64 CPU), the Unisys ES7000 (32 Processors) The Sun Sun Fire and the IBM X Series.

Vertical scaling has several benefits over horizontal scaling for Oracle databases:

  • RAC is not required
  • Machine resources (especially CPU) are instantly available for sharing
  • A single-server requires less overhead and management

The Sun architecture has broken the Oracle data warehouse TPC-H World record using a vertical scalable architecture.

"Running on a single Sun Fire? 25K server with 72 UltraSPARC IV+ 1.5 GHz processors and the Solaris? 10 Operating System (OS), Oracle Database 10g Release 2 with Automatic Storage Management achieved a record-breaking performance of 105,430.9.

Oracle Database 10g Release 2 repeatedly demonstrates its superior fit in demanding data warehouse environments, " said Richard Sarwal, vice president of Server Performance, Oracle. "The addition of this benchmark helps to prove that no matter how much our customers' data warehouses grow, the Oracle Database will continue to deliver the best, most consistent database performance."

Combining horizontal scalability and vertical scalability

So, which is better for high-availability databases using Oracle Real Application Clusters (RAC)?

In the real world, savvy corporations combine vertical scalability and horizontal scalability.  They start with a large vertical architecture server, adding resources as-needed.  If continuous availability is also required, they may have a mirrored server using long-distance RAC or Oracle Streams.

When the single server is approaching capacity, they the "scale out" with the horizontal scalability, employing RAC and adding additional servers, each with a vertical scaling architecture.

Sun  notes:

"For large databases, vertically-scalable architectures can provide higher levels of scalability than large numbers of horizontally-scalable systems with distributed databases, and vertically-scalable servers are often easier and less expensive to manage."

If you like Oracle tuning, you may enjoy the new book "Oracle Tuning: The Definitive Reference", over 900 pages of BC's favorite tuning tips & scripts. 

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 -  2020

All rights reserved by Burleson

Oracle ® is the registered trademark of Oracle Corporation.