U-SQL Data Sources
One of the major value propositions of U-SQL is that it allows to query data where it lives. For external systems, such as Microsoft Azure SQL Database, this is achieved with federated queries against data sources.
In order to query these external data sources, a data source object has to be created and referenced that abstracts the connection information as well as information about its capabilities to execute query expressions passed and translated from U-SQL to the its local query engine.
Data Source DDL Statements
The following are the DDL statements that allow to manage data sources:
Datasource_DDL_Statement := Create_Datasource_Statement | Alter_Datasource_Statement | Drop_Datasource_Statement.