TEIID-4423 adding a note about subqueries

reference/Nondeterministic_Function_Handling.adoc

@@ -11,4 +11,6 @@ Teiid categorizes functions by varying degrees of determinism. When a function i
 
 4.  *Command Deterministic* - the result of function evaluation is only deterministic within the scope of the user command. This category include the curdate, curtime, now, and commandpayload functions. Command deterministic functions are delayed in evaluation until processing to ensure that even prepared plans utilizing these functions will be executed with relevant values. Command deterministic function evaluation will occur prior to pushdown - however multiple occurrences of the same command deterministic time function are not guaranteed to evaluate to the same value.
 
-5.  *Nondeterministic* - the result of function evaluation is fully nondeterministic. This category includes the rand function and UDFs marked as nondeterministic. Nondeterministic functions are delayed in evaluation until processing with a preference for pushdown. If the function is not pushed down, then it may be evaluated for every row in it’s execution context (for example if the function is used in the select clause).
+5.  *Nondeterministic* - the result of function evaluation is fully nondeterministic. This category includes the rand function and UDFs marked as nondeterministic. Nondeterministic functions are delayed in evaluation until processing with a preference for pushdown. If the function is not pushed down, then it may be evaluated for every row in it’s execution context (for example if the function is used in the select clause).  
+
+NOTE: Uncorrelated subqueries will be treated as deterministic regardless of the functions used within them.