What are the differences between EXECUTE and EXECUTE IMMEDITATE, is I can’t see any difference in the supplied documentation...
Properties of EXECUTE, EXECUTE IMMEDIATE and dbc.SysExecSql are:
EXECUTE IMMEDIATE is the ANSI equivalent of Teradata "CALL dbc.SysExecSQL()". [The argument for either is a character string that contains a SQL statement.]
EXECUTE requires separate PREPARE statement, and allows parameter values to be passed (USING). [The argument for EXECUTE is a "prepared SQL statement" object.]
All three statement types can be used multiple times in one stored procedure.