01What is the primary performance drawback of a CORRELATED subquery?
02In a Recursive CTE, what comprises the 'Base Case'?
03What is the common result when using WHERE id NOT IN (SELECT id FROM ...) if the subquery returns at least one NULL value?
04In modern database engines, what is the 'Optimization Fence' effect that occurs when a Common Table Expression (CTE) is materialized?
05Which of the following is the most efficient way to rewrite a correlated subquery in a SELECT list that calculates a count for every row?