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

 
 Home
 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
 Analysis
 Design
 Implementation
 Oracle Support


 SQL Tuning
 Security

 Oracle UNIX
 Oracle Linux
 Monitoring
 Remote s
upport
 Remote plans
 Remote
services
 Application Server

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

 Remote S
upport  
 Development  

 Implementation


 Consulting Staff
 Consulting Prices
 Help Wanted!

 


 Oracle Posters
 Oracle Books

 Oracle Scripts
 Ion
 Excel-DB  

Don Burleson Blog 


 

 

 


 

 

 

 

   

Oracle standby reporting database


Oracle Tips

 
 
QUESTION: I want to create a cloned database that can be used for crystal reporting and standby databases.  What's the best approach?
 
ANSWER: Oracle offers several options for creating a read-only copy of the database, each depending on your tolerance for stale data in the reporting database:

         Physical Standby Database (redo apply)
         Logical Standby Database (SQL Apply)
         Simple Replication (using snapshots)
         Streams Replication (using database, schema-level or tables level data capture)

Unless you have created a manual standby you are using Oracle data guard. Data guard is the term that defines oracle's managed standby. I think you are confusing it with Data guard Broker which is a separate configurable tool.   Let's take a closer look at each approach:
 
Physical Standby Database
 
This ancient method of transporting and applying redo logs has been around for over 15 years and is very simple and reliable.  Starting in 9i, the physical standby will transfer redo as it is generated, greatly reducing the chance of lossing data.  The database can be queried read-only and the data will be current as of the transaction that was applied. 
 
  • Physical Standby Database Downsides: The possibility of losing some transactions during a system crash.
  • Physical Standby Database Staleness: In 9i and 10g, redo apply must be stopped when the database is opened read only.  In 11g, redo apply continues when the database is opened read only.
 
Logical Standby Database
 
The Logical Standby Database uses SQL Apply to keep a consistent replication of the primary database.  The tables that are managed are also protected from modification. The main advantage of logical database is that indexes and materialized views can be added to the standby database.  This is perfect for reporting application where the DBA will create pre-joined, de-normalized table structures for super-fast queries.  For details, see the book "Oracle Data Guard Standby Database".
 
  • Logical Standby Database Downside:  Changes made to the standby to support reporting can case performance problems it the standby is activated.
  • Logical Standby Database Staleness:  Same as the Physical Standby except that the standby is always open.
     
 
Simple Replication
 
Oracle offers simple (snapshot) replication whereby mview logs are created for all replicated tables, and the logs are used to update the tables on the standby database at specified intervals (from "on commit" to any delayed time period).  For details, see the book "Oracle Replication".
 
  • Simple Replication Downside: No managed switchover/failover however both databases are open and available.
  • Simple Replication Staleness:  User-defined, from "On commit" to a defined refresh interval.
 
Streams Replication
 
Oracle Streams is a great solution and Streams provides high-speed data replication with a minimum of set-up fuss.  Using database, schema or table level data capture it is easy to define a replication strategy.  Both databases are open read-write.  There is no protection such as on the Logical Standby.  For more details, see the book "Oracle Streams" and its handy code depot.
 
  • Streams Replication Database Downside: No managed switchover/failover but both databases open and available.
  • Simple Replication Database Staleness:  Normally negligible.

 


 

 

��  
 
 
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.