A star join dimension work file node is labeled WFSJDn, where n represents the order in which the work file is used. For example, a node that is labeled WFSJD2 represents the second star join work file. This node is , by default, displayed as an arrow polygon.
DB2® generates star join dimension work files in the beginning of the data manager pushdown star join subquery. DB2 then treats those star join dimension work files like the work files that result from a sort operation; DB2 uses a work file scan (WFSCAN) to access the star join dimension work files.