Que. |
The result of the UNION operation between R1 and R2 is a relation that includes
|
a. |
all the tuples of R1 |
b. |
all the tuples of R2 |
c. |
all the tuples of R1 and R2 |
d. |
all the tuples of R1 and R2 which have common columns |
Answer given is d. Shouldn't it be c???