BC remote Oracle DBA - Call (800) 766-1884  
Oracle Consulting Oracle Training Development

Remote DBA

Remote DBA Plans  

Remote DBA Service

Remote DBA RAC

   
Remote DBA Oracle Home
Remote DBA Oracle Training
Remote DBA SQL Tuning Consulting
Remote DBA Oracle Tuning Consulting
Remote DBA Data Warehouse Consulting
Remote DBA Oracle Project Management
Remote DBA Oracle Security Assessment
Remote DBA Unix Consulting
Burleson Books
Burleson Articles
Burleson Web Courses
Burleson Qualifications
Oracle Links
Remote DBA Oracle Monitoring
Remote DBA Support Benefits
Remote DBA Plans & Prices
Our Automation Strategy
What We Monitor
Oracle Apps Support
Print Our Brochure
Contact Us (e-mail)
Oracle Job Opportunities
Oracle Consulting Prices





   

 

 

 

Remote DBA services

Remote DBA Support

Remote DBA RAC

Remote DBA Reasons

Remote Oracle Tuning

Remote DBA Links

Oracle DBA Support

Oracle DBA Forum

Oracle Disaster

Oracle Training

Oracle Tuning

Oracle Training

 Remote DBA SQL Server

Remote MSSQL Consulting

Oracle DBA Hosting

Oracle License Negotiation

 

 


 

 

 

 

   
  Oracle Tips by Burleson

Benefits of RAC 

In the beginning was Oracle Parallel Server or OPS, now we have Real Application

Clusters or RAC. It is more than just a name change. RAC provides a process known asw cache-fusion which allows direct sharing of Oracle database blocks between cache areas of Oracle instances participating in RAC via a high speed interconnect. This direct sharing eliminates the biggest performance robbers in the OPS architecture, the DB block PING.     

A DB block PING would occur when an instance participating in an OPS database would have a block in its cache that another participating instance required. In OPS if another instance required the block in the cache of a second instance, the block would have to written out to disk, the locks transferred and then the block re-read into the requesting instance. As you can imagine all of this IO was expensive in terms of  time and performance.      

The new RAC with cache fusion exploits the new high speed buses and architectures available in the new servers. By eliminating the blockage caused by pinging, RA enables better, more efficient scaling. In order to add more processing or user capacity you simply add a server to the LAN, load the appropriate software and Oracle9i and you are up and operating.

What Is a DB Cluster? 

A DB cluster consists of a group of independent servers, connected via a LAN

that share a set of disk assets via the LAN and have a high speed cluster interconnect that allows connection of their processors to the other processors in the cluster. The clusters do not share memory and act as independent servers. The servers can either be single processor or SMP (Symmetric Multi-Processor) nodes. A DB cluster provides fault-tolerance and allow for modular growth. By having the built in redundancies of multiple servers the chance that a single point of failure will prevent database access is unlikely. 

DB Cluster Architectures 

Essentially there are only two basic architectures used in DB clusters, these are the shared-nothing and shared-disk. The shared-nothing cluster uses dedicated disk assets for each server in the cluster. The shared-disk cluster uses a SAN type storage array to serve the cluster.      

Examples of systems that use the shared nothing architecture are the IBM RS/6000 SP and the federated database approach used by SQL Server. This architecture is rapidly losing ground to the shared-disk architecture.      

The shared-disk architecture is being adopted almost 100% by IBM, SUN and HP and other vendors. It offers better redundancy, and , better connectivity through technologies such as fiber-channel, hub and shared SCSI.

See Code Depot


www.oracle-script.com

Remote DBA Service
 

Oracle Tuning Book

 

Advance SQL Tuning Book 

BC Oracle support

Oracle books by Rampant

Oracle monitoring software

 

 

 

 

 

 

BC Remote Oracle Support

Remote DBA

Remote DBA Services

Copyright © 1996 -  2013 by Burleson. All rights reserved.

Oracle® is the registered trademark of Oracle Corporation.