Use DUW processing to remain connected to your default (or current) location, and have the ability to execute a limited range of statements on data objects in another local or remote location. You can use INSERT, UPDATE, DELETE, and SELECT commands with three-part object names, while OPEN, FETCH and CLOSE commands are valid for DUW processing with embedded SQL.
An application simply uses the fully qualified name (location-name.authid.object-name) of a table or view that resides in the other location. Based on information in the system catalog tables on the current XDB Server, the request is sent to the appropriate XDB Server and data is returned.
Use of the DUW option requires that you reference no more than one location per SQL statement. If you need to work with objects in several locations, you must use multiple statements, one location per statement.
The XDB Server does not currently support two-phase commit or distributed queries.