GATE 2026 DA – Question 61

Database Management and Warehousing · ER model and relational model · 2 marks · Numerical answer

Consider an ER model with the entities E1(A11,A12,A13) and E2(A21,A22,A23), where, A11, A12, A13 are the attributes of E1, and A21, A22, A23 are the attributes of E2. Let A22 be a multi-valued attribute. A11 and A21 are the primary keys of E1 and E2, respectively.

Let R12 be a many-to-many relationship between E1 and E2. Participation of both E1 and E2 in R12 is total.

The minimum number of relations required to convert the ER model into relational model (assuming there is no other functional dependency) where each relation is in third normal form (3NF) is __________ . (*Answer in integer*)

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: 4

Explanation

Each entity gets a relation, E1(A11, A12, A13) and E2(A21, A23 and the single-valued attributes). The multi-valued attribute A22 needs its own relation, E2_A22(A21, A22), to stay in normal form. A many-to-many relationship always needs a separate relation too, R12(A11, A21), and total participation does not allow it to be folded into either entity. That is 4 relations, and each is in 3NF.