Role-based syntax is not supported in SAP Sybase IQ 15.x databases.
When using SAP Sybase IQ 16.0 to connect to a 15.x database, only authority-based syntax is valid. Using role-based syntax returns errors. For example, GRANT ROLE returns an error message; GRANT MEMBERSHIP IN GROUP does not.
Beyond this limitation, there should be no change in functionality and no noticeable change in performance using SAP Sybase IQ 16.0 with a 15.x database.