Query Handler

Description

The Query Handler is the technical object which is responsible to execute the Function. Sometimes it is also referred to as Technical Handler. It comprises all logic which is required to get the requested data from a specific Source System. It is located in the running Agent Instances. A Query Handler is assigned to a Function while creation within the Portal in the menu Virtual Datasets. Once a Function is linked to a Query Handler type, the type cannot be changed anymore.

Additional Information

All Query Handlers are maintained and provided by the VDP Team. In case of software releases, the Agents automatically downloads the new Query Handler versions from the backend.

For each type of System there exists a specific Query Handler. For some Systems, which allow for different types of data retrievals, there exists more. E.g. for SQL Server, there exists a Query Handler to connect directly to tables and another one for procedures.

All Query Handlers at the status quo are programmed in C#.