GATE CSE 2024 | Set 2 | Question: 35

Question

​​​​​The relation schema, Person (pid, city), describes the city of residence for every person uniquely identified by pid. The following relational algebra operators are available: selection, projection, cross product, and rename.

To find the list of cities where at least $3$ persons reside, using the above operators, the minimum number of cross product operations that must be used is

• A. $1$
• B. $2$
• C. $3$
• D. $4$

Answer 1

To find the list of cities where at least $3$ persons reside, we need to do cross product of 3 tables, So, minimum only 2 cross products are required. Video Solution Here.