Please add dynamic IF evaluation to U-SQL
Today, U-SQL allows control flow IFs based on compile time values. Often a script may depend on a dynamic value (e.g., if a rowset expression was empty or a certain threshold value was reached), It would be convenient, if the language would allow an IF expression in the algebra that during execution would either execute or not execute a subtree in the job graph.
This is a massive omission in functionality. Makes conditionals very very limited in use.