In BAAN 5.0c,there is a session ttdba0511m000(Transfer Database User File to RDBMS Administrator Module),if double click a record in the Grid,the session ttdba0110s000 is executed.

What is the DB User File,after press the choice Trasfer ,What does the Baan do.

It loads the <dbms>_users file in $BSE/lib/<dbms>

so for example your ora_users... inf_users, etc..

By "loading" i mean it fills the appropriate ttdba tables with
the info stored in that file.

That file is the link between the driver and the database, storing
username, encrypted password, and which database / shema to connect
to..

Dave