Relational Schema

Consider a relational database schema with a relation $R(A, B, C, D)$. If $\{A, B\}$ and $\{A, C\}$ are the only two candidate keys of the relation $R$, then the number of superkey...

Consider the following relational schema along with all the functional dependencies that hold on them. R1(A, B, C, D, E): { D → E, EA → B, EB → C} R2(A, B, C, D): { A → D, A → B, C...

Consider the following relational schema: Students (rollno: integer, name: string, age: integer, cgpa: real) Courses (courseno: integer, cname: string, credits: integer) Enrolled (...

Consider the following relational schema: Students ($$\mathrm{\underline {rollno:integer}}$$, name: string, age: integer, cgpa: real) Courses ($$\mathrm{\underline {courseno:intege...

Which of the following is NOT a superkey in a relational schema with attributes $$V, W, X, Y, Z$$ and primary key $$V Y?$$

Consider the following relational schema: employee ( empId, empName, empDept ) customer ( custId, custName, salesRepId, rating) SalesRepId is a foreign key referring to empId of th...

Let $$R\left( {A,B,C,D} \right)$$ be a relational schema with the following functional dependencies: $$A \to B,\,\,B \to C,\,\,C \to D$$ and $$D \to B.$$ The decomposition of $$R$$...

Consider a relation scheme $$R = \left( {A,\,B,\,C,\,D,\,E,\,H} \right)$$ on which the following functional dependencies hold: $$\left\{ {A \to B,\,\,BC \to D,\,\,E \to C,\,\,D \to...

In a schema with attributes $$A, B, C, D,$$ and $$E,$$ following set of functional dependencies are given $$\eqalign{ & \,\,\,A \to B \cr & \,\,\,A \to C \cr & CD \to E \cr & \,\,\...

An instance of a relational scheme R(A, B, C) has distinct values for attribute A. Can you conclude that A is a candidate key for R?