Natural Join

Consider the relations $$r(A, B)$$ and $$s(B, C),$$ where $$s.B$$ is a primary key and $$r.B$$ is a foreign key referencing $$s.B.$$ Consider the query $$Q:$$ $$\,\,\,\,\,\,\,\,\,$...

Consider two relations $${R_1}\left( {A,B} \right)$$ with the tuples $$(1,5), (3,7)$$ and $${R_2}\left( {A,C} \right) = \left( {1,7} \right),\left( {4,9} \right).$$ Assume that $$R...

Database table by name Loan_Records is given below. Borrower Bank_Manager Loan_Amount Ramesh Sunderajan 10000.00 Suresh Ramgopal 5000.00 Mahesh Sunderajan 7000.00 What is the outpu...

The following functional dependencies hold for relations R(A, B, C) and S(B, D, E): $$$\eqalign{ & B \to A \cr & A \to C \cr} $$$ The relation R contains 200 tuples and the relatio...

Let R and S be two relations with the following schema R ( P , Q , R1, R2, R3) S ( P , Q , S1, S2) Where {P, Q} is the key for both schemas. Which of the following queries are equi...

Consider the relations r 1 (P, Q, R) and r 2 (R, S, T) with primary keys P and R respectively. The relation r 1 contains 2000 tuples and r 2 contains 2500 tuples. The maximum size...

Let r be a relation instance with schema R = (A, B, C, D). We define $${r_1} = {\pi _{A,B,C}}\left( r \right)$$ and $${r_1} = {\pi _{A,D}}\left( r \right)$$. Let $$s = {r_1}*{r_2}$...

Consider the following relation schema pertaining to a students database: Students ( rollno , name, address) Enroll( rollno,courseno , coursename) Where the primary keys are shown...

A library relational database system uses the following schema USERS (User #, User Name, Home Town) BOOKS (Books # Book Title, Author Name) ISSUED (Book #, User #, Date) Explain in...