Question: Consider two tables X ( A , B ) and Y ( A , C ) . A , B , C are attributes. A
Consider two tables XAB and YAC A B C are attributes. A is the primary key in both X and Y Assume that NULL values are NOT permitted for A B and C; and the two tables X Y are not empty.
Decide if the following two queries are equivalent that is if they are guaranteed to produce the same answer no matter what the actual data in X and Y are. Do not consider the sequence of the returned rows
: select A from Y where A in select A from X;
: select A from X where A in select A from Y;
Group of answer choices
True
False
Step by Step Solution
There are 3 Steps involved in it
1 Expert Approved Answer
Step: 1 Unlock
Question Has Been Solved by an Expert!
Get step-by-step solutions from verified subject matter experts
Step: 2 Unlock
Step: 3 Unlock
