The Real MTCS SQL Server 2008 Exam 70/432 Prep Kit- P85: Congratulations on your journey to become certified in SQL Server 2008. This book will help prepare you for your exam and give you a practical view of working with SQL Server 2008. | 402 Chapter 9 Managing Replication Components Two agents are used in Snapshot Replication snapshot and distribution. Snapshot Agent This agent is a shared agent for all replication types. For any kind of replication it needs to have initial schema and data scripts. The snapshot agent s job is to generate data scripts for the objects you are replicating. These scripts are written to a folder in the file system called a snapshot folder. Apart from writing scripts to snapshot folder the snapshot agent will write commands to the distribution databases. Distribution Agent This agent will read from a snapshot folder and distribution database to propagate to the subscriber end. In snapshot replication the subscription database is not read only which means that you have the option of modifying the data at the subscriber database. However your changes will be reverted back when the publisher snapshot agent runs. Transactional Transactional replication is the most used replication type out of the three available replication types. The most valuable feature of the transactional replication is the ability to replicate incremental changes rather than applying the all-data set. Transactional replication uses transactional log to generate transactions for replication. However you don t need your database recovery model to be either Full or Bulk-Logged. Transactional replication works with every database model. You need to have a primary key for all the tables that you are going to replicate. Transactional replication is much more scalable than snapshot replication mainly due to the fact that transactional replication takes less time than snapshot replication. Here are the scenarios where you can use transactional replication Replicate huge volumes of data. As transactional replication propagates incremental data to the subscribers it can handle large volumes of data. For real-time application. For real-time applications you need to replicate data with minimum latency. Because .
