In order to connect a Visual DBA or IDMS SERVER ODBC session to a Mainframe IDMS CV, an ODBC Data Source or node must be used. One of the options is to choose a System Data Source Name (SYSTEM DSN) or a User Data Source Name (USER DSN). What the difference between the two Data Source Types?
Release: All supported releases.
Typically, data sources meant to be used by Windows services must be defined as System Data Sources and are available to all users and services of the machine. Whereas User data sources are available only to the user who defined them, and as a result will not be available to any other users of the machine.