Microsoft Office 2000/Visual Basic Programmer's Guide

When to Choose Database Replication

Database replication is well suited to business solutions that need to:

• Share data among remote offices.   You can use database replication to create copies of a corporate database to send to each satellite office across a wide area network (WAN). Each location enters data in its replica, and all remote replicas are synchronized with the replica at corporate headquarters. Individual replicas can maintain local tables that contain information not included in the other replicas in the set.
  
  
• Share data among dispersed users.   New information that is entered in the database while sales representatives are out of the office can be synchronized any time the sales representatives establish an electronic link with the corporate network. As part of their workday routine, sales representatives can dial in to the network, synchronize the replica, and work on the most current version of the database. Because only the incremental changes are transmitted during synchronization, the time and expense of keeping up-to-date information are minimized. By using partial replicas, you can synchronize only specified parts of the data.
  
  
• Make server data more accessible.   If your solution doesn't need to have immediate updates to data, you can use database replication to reduce the network load on your primary server. Introducing a second server with its own copy of the database improves response time. You determine the schedule for synchronizing the replicas, and you can adjust that schedule to meet the changing needs of your users. Replication requires less centralized administration of the database while offering greater access to centralized data.
  
  
• Distribute solution updates.   When you replicate your solution, you automatically replicate not only the data in your tables, but also your solution's objects. If you make changes to the design of the database, the changes are transmitted during the next synchronization; you don't have to distribute complete new versions of the software.
  
  
• Back up data.   At first glance, database replication might appear to be very similar to copying a database. However, while replication initially makes a complete copy of the database, thereafter it simply synchronizes that replica's objects with the original objects at regular intervals. This copy can be used to recover data if the original database is destroyed. Furthermore, users at any replica can continue to access the database during the entire backup process.
  
  
• Provide Internet or intranet replication.   You can configure an Internet or intranet server to be used as a hub for propagating changes to participating replicas.