You can use a query band statement to change a sessions routing rule dynamically. The query band rule makes sure that particular reporting or load processes use a specific routing rule.
If the client application is already using the routing rule, then the query band has no effect. If the client specifies a routing rule different from the currently used, it disconnects its Unity sessions and reconnects using the specified routing rule.
SET QUERY_BAND = 'UNITYROUTING=DB1_Only;’ For Session;