Explanation:None. 4. If we want to retain all duplicates, we must write ________ in place of union.
A. Union all
B. Union some
C. Intersect all
D. Intersect some
Answer:A
Explanation:None. 4. If we want to retain all duplicates, we must write ________ in place of union.
A. Union all B. Union some C. Intersect all D. Intersect some
Explanation:Union all will combine all the tuples including duplicates. 5. (Select course id