Transactions that occur in a primary database are detected by a Replication Agent and transferred to the local Replication Server, which distributes the information across a network to Replication Servers at destination sites. In turn, these Replication Servers update the replicate database according to the requirements of the remote client.
The primary data is the source of the data that Replication Server replicates in other databases. You publish data at primary sites to which Replication Servers at other (replicate) sites subscribe. To do so, you first create a replication definition to designate the scope and location of the primary data. The replication definition describes the structure of the table. A database replication definition can replicate individual tables, functions, and DDLs. A table replication definition describes the structure of the table and states the key that is to be used to query the table for updates and deletes.
Creating a replication definition does not, by itself, cause Replication Server to replicate data. You must also create a subscription against the replication definition to instruct Replication Server to replicate the data in another database. A subscription resembles a SQL select statement: It can include a where clause to specify the rows of a table you want to replicate in the local database.
You can have multiple replication definitions for a primary table to filter different objects. Replicate tables can subscribe to different replication definitions to obtain different views of the data.
After you have created subscriptions to replication definitions or publications, Replication Server replicates transactions to databases with subscriptions for the data.
