Rules for Using Scalar Subqueries in ROLLBACK Requests - Teradata Vantage

You can specify a scalar subquery in the WHERE clause of a ROLLBACK request in the same way you can specify one for a SELECT request.

You can also specify a ROLLBACK request with a scalar subquery in the body of a trigger. However, the database processes any noncorrelated scalar subquery you specify in the WHERE clause of a ROLLBACK statement in a row trigger as a single-column single-row spool instead of as a parameterized value.