01Which join algorithm builds an in-memory structure for the smaller table to enable O(1) lookup during the scan of the larger table?
02What is the technical difference between UNION and UNION ALL?
03Which physical join algorithm is the most efficient for massive, already-sorted datasets by zipping the two tables together?
04What happens when a Hash Join exceeds the available memory (work_mem) in the database engine?
05Which of the following set operations will NOT perform an automatic duplicate removal, making it the most performant for appending two result sets?