Proxy users access Vantage through a middle-tier application set up for trusted sessions. They are authenticated by the application rather than the database. The GRANT CONNECT THROUGH statement assigns role-based database privileges to proxy users. To establish privileges for a connection to the database, the application submits the SET QUERY_BAND statement when it connects the user. The SET QUERY_BAND statement and the rules for how it is applied to each proxy user must be coded into the application as part of setup for trusted sessions.