Subscriptions resemble SQL select statements. They identify the replication definition or publication to which you are subscribing, the source and destination databases and data servers, and the materialization method by which the initial information is to be copied. You can use a where clause to specify a subset of rows or parameters that the destination database receives from the source database. This chapter describes how to materialize subscription data and manage subscriptions.
Materialization is the process of copying data specified by a subscription from a primary database to a replicate database, thereby initializing the replicate table. Replicate data can be transferred over a network, or, for subscriptions involving large amounts of data, loaded initially from media. Initialization from media is called bulk materialization. You use one of four materialization methods, depending on how you want materialization to affect the replication system. See “Subscription materialization methods” for more information.
Subscriptions for database replication definitions instruct Replication Server to replicate database objects from the primary to the replicate database. You can choose to replicate or not replicate individual tables, transactions, functions, system stored procedures, and data definition language (DDL). This method requires only a single database replication definition for each primary database and a single subscription for each subscribing database. See Chapter 12, “Managing Replicated Objects Using Multisite Availability,” for detailed information about database replication definitions and database subscriptions.
Subscriptions for table replication definitions instruct Replication Server to replicate data from primary tables into specified replicate tables. After you have created a replication definition for a primary table, replicate sites must subscribe to the replication definition at the primary database to receive updates.
Subscriptions for function replication definitions require you to use the no-materialization or the bulk materialization methods. See “No materialization” and “Bulk materialization”. See also Chapter 10, “Managing Replicated Functions” for information about replicated functions.
You can subscribe to a group of replication definition articles by subscribing to a publication. Publication subscriptions cannot contain where clauses. To subscribe to a subset of rows in an article, you must include a where clause when you create the article. See “Using publication subscriptions” for information about subscribing to publications.
You create subscriptions at the Replication Server managing the database where the replicate data is to be maintained. Your previously created replication definition provides the location of the primary data and defines the structure of the primary table and optionally, of the replicate table, where they differ.
