Microsoft® SQL Server™ 2008 All-In-One Desk Reference For Dummies®

VIII.5.2. Defining a Replication Publishing Model

With replication, three different models exist. These models define whether the entire database is replicated (or only the changes), how often the replication occurs, and who can make changes to the source database.

• Snapshot replication: Snapshot replication involves making a copy of the publication at a moment in time. The entire publication is then replicated to the receiving database. Snapshot replication is the easiest to implement, but takes the most bandwidth.

• Transactional replication: Transactional replication is used to constantly update and publish the articles. This is used when the subscribers need access to changes as they occur. All changes to the database are recorded in the transaction log. The log reader agent then reads the transaction log to replicate the changes to the receiving database. These changes are then applied to the receiving database.

• Peer-to-peer transactional replication: Peer-to-peer replication is used for applications that might read or modify data at any of multiple databases participating in replication. It's built on the foundation of transactional replication, but peers in transactional replication can both read and modify changes; subscribers in transactional replication can only receive the changes.

• Merge replication: Merge replication is used when multiple locations need to be able to update the data. For example, a retail chain might have multiple stores that all need to submit sales and ...