Shared Data Sources and Embedded Data Sources
Reporting Services provides two ways to define connections to the data sources used in reports, report models, and data-driven subscriptions. Both approaches are similar, so you can switch between embedded data source connections and shared data source items if one approach offers functionality that you want to use. The difference between the two approaches is in how the connection data is stored and managed.
An embedded data source is report-specific. The description of a data source connection is embedded in the report definition. Embedded data source connection information can be used only by the report in which it is embedded. The connection information is internal to the report or subscription (for example, if you view the XML syntax of the report, you can see the connection information in the XML). To define and manage embedded data sources, use the Data Source Properties page of a report. For more information, see Managing Report Data Sources.
A shared data source is a separate item stored on the report server that describes a data source connection. It is reusable across multiple reports and subscriptions. Shared data sources are required by report models and optional for reports and data-driven subscriptions.
You can create and manage shared data sources separately from the reports and data-driven subscriptions that use it. You can move a shared data source to different folder locations, name a shared data source, and set security on it to determine its availability. The following icon indicates a shared data source item in the folder hierarchy:
Shared data sources are useful when you have data sources that you use often. Examples of shared data sources that may be useful include the following:
A connection to a production server that supports business operations.
A connection to a frequently-used test server.
A connection to an employee database to support data-driven subscriptions.
Shared data sources are easier to adjust when there are changes to the data source. If you move or rename the database or change the database login, you can update the connection string once to effect a corresponding change in all the reports and subscriptions that use the data. You can also disable a shared data source item to prevent report processing. For more information, see Creating, Modifying, and Deleting Shared Data Sources.