This command lets you enter the name of a predefined custom user transform. A user-defined transform is a user-defined function that returns a table or a stream. Its input arguments can be scalars or cursors. A cursor is an object representing a subquery, which the user-defined transform can use to read the subquery results. The subquery can be relational or streaming.
The UDX does have to be predefined and it cannot take arguments.
It can return either a table or a stream. If it is a table you can specify a column that will contain the ROWTIME.