A many-to-one relationship exists from entity set r₁ to entity set r₂. If Pk(r) denotes the primary key of relation r, how is it represented using functional dependencies?
Pick an option to check yourself, or open the answer below.
Show answer & explanation
Correct answer: A. Pk(r₁) → Pk(r₂)
Explanation
Each r₁ entity relates to at most one r₂ entity, so r₁'s key determines r₂'s key.
More Database Management Systems questions
- Database systems that store each relation in a separate operating system file may use the operating system's authorization scheme, instead…
- Let R₁(a, b, c) and R₂(x, y, z) be relations in which a is a foreign key of R₁ referring to the primary key of R₂. Consider: (a) insert int…
- For a database relation R(a, b, c, d) where the domains of a, b, c and d include only atomic values, and only the following functional depe…
- Consider the following schedules involving two transactions: S₁: r₁(X); r₁(Y); r₂(X); r₂(Y); w₂(Y); w₁(X) S₂: r₁(X); r₂(X); r₂(Y); w₂(Y); r…
- Relations produced from E - R Model will always be in ________.
- In a Hierachical database, a hashing function is used to locate the ________.