The way in which a driver handles function calls from a Unicode application determines whether it is considered a "Unicode driver."
Instead of the standard ANSI SQL function calls, such as SQLConnect, Unicode applications use "W" (wide) function calls, such as SQLConnectW. Hybrid Data Pipeline Driver forODBC supports "W" function calls, so the Driver Manager can pass them through to the driver without conversion to ANSI.
For Hybrid Data Pipeline Driver forODBC on UNIX and Linux, the Driver Manager determines the type of Unicode encoding of both the application and the driver, and performs conversions when the application and driver use different types of encoding. This determination is made by checking two ODBC environment attributes: SQL_ATTR_APP_UNICODE_TYPE and SQL_ATTR_DRIVER_UNICODE_TYPE. Driver Manager and Unicode Encoding on UNIX/Linux describes in detail how this is done.
