Using a Reference Table Query in a Join

Use a join to combine incoming event data and source data from a reference table query.

1. Obtain the necessary information about the external database table containing the information you wish to look up:
   • the name of the table containing the data.
   • the schema for that table.
   • the service to use to connect to it.
2. Create the reference table query in your project.
3. Create the input stream or window. A stream and a reference in a join only produces a stream; a window and a reference in a join produces a window, provided that the primary keys are set in the reference and input window.
4. Create a join to combine the incoming event data from the input stream or window with the data obtained from the reference table query:
   1. From the Palette, under Streams and Windows, select Join(), then click an empty area in the diagram.
   2. From the Palette, select Connector and connect the input stream or window to the join.
   3. From the Palette, select Connector and connect the reference query table to the join.