Data Sources

A data source contains the information necessary to access source data for an object such as a cube. Although the term data source is sometimes used to refer to the source data itself, in this topic it refers to the data source object, which is used by Microsoft® SQL Server™ 2000 Analysis Services to establish connections to the source data.

A data source specifies an OLE DB provider and settings for the other properties in the connection string used to access the source data. The property set varies according to the selected provider. Typically, many of the properties are optional, so the creation of a data source can be accomplished quickly.

Data sources are created in the Data Link Properties dialog box. For more information, see Specifying Data Sources.

Analysis Services supports many data sources, including SQL Server 2000 databases and databases created by other products. For more information, including a list of the database products whose databases can be selected when you create a data source, see Specifications and Limits.

When defining a new data source in the Data Link Properties dialog box, you can select a database that is accessed through an ODBC driver as the source of data if you specify an OLE DB provider that supports ODBC drivers. One such provider is Microsoft OLE DB Provider for ODBC Drivers, which is supplied with Analysis Services. If you use this provider, you must create a system data source name (DSN) before you create the data source. To create a system DSN, use the ODBC Data Source Administrator in Control Panel.

Data sources are immediately subordinate to the following objects in the object hierarchy:

• Database

  A database can contain multiple data sources, which are shared among the cubes, partitions, and dimensions in the database.

• Cube

  A cube can have only one data source. When a cube is created, its data source is selected from the database's data sources, or a new data source can be created. The cube's partitions can have different data sources than the cube's data source.

  A data source for a linked cube must specify Microsoft OLE DB Provider for Analysis Services or another provider that is compliant with the OLAP section of the OLE DB specification dated March 1999 (2.6).

• Partition

  A partition can have only one data source. It is selected from the database's data sources or created when the partition is created. Each partition in a cube can have a different data source; however, all the data sources must reference sources of data that contain:

  • A fact table with the same structure and columns.
    
    
  • The same set of dimension tables that is used in the cube's schema. Among the sources of data, the dimension tables must have the same structure and columns.

In addition, each dimension has a data source. A dimension can be included in a cube only if they have the same data source.

After data sources are created, shared dimensions are typically the next objects that are created. For more information, see Dimensions.

Data sources are also used in incremental updates of cubes and partitions. Before you perform an incremental update, you must create a data source for the source data that will be incorporated into the cube or partition by the incremental update. For more information about incremental updates, see Updating and Refreshing Cube Data.

In Analysis Manager, a data source is identified by the following icon:

If you are programming with Decision Support Objects (DSO), the class type associated with the data source is clsDataSource. For more information, see clsDataSource.

See Also

Operational Considerations

Processing Tab (Properties Dialog Box)

Specifying Data Sources