E-R Model And Relational Algebra

Enrollment

The assignment operator is denoted by

• ->
• <-
• =
• ==

The _______ operator takes the results of two queries and returns only rows that appear in both result sets.

• Union
• Intersect
• Difference
• Projection

The _________ provides a set of operations that take one or more relations as input and return a relation as an output.

• Schematic representation
• Relational algebra
• Scheme diagram
• Relation flow

which of the following is correct relational algebra expression for below query: 1 .Select All the accounts records having branch name "Los Agleles"

• σ branch_name=“Los Angeles” (account)
• Π branch_name=“Los Angeles” (account)
• Π (acct_id , branch_name,balance) Account
• none of the above

Which of following is the correct relational algebra expression below query? Selects the account IDs of all accounts with a balance of$300 or more

• Π acct_id (σ balance≥300 (account))
• σ acct_id(Π balance≥300(account))
• σ balance≥300 (account))
• none of the above

Which of the following is correct relational algebra expression for below query? Listout only the consistent data of both relation Borrower and Loan.

• σ borrower.loan_id=loan.loan_id (borrower × loan)
• Π borrower.loan_id=loan.loan_id(borrower × loan)
• borrower × loan
• none of the above

Which of the following is correct relational algebra expression for below query? “Find the names of all customers with loans.”

• Π cust_name(σ borrower.loan_id=loan.loan_id(borrower × loan))
• Πcust_name(borrower ⋈ loan)
• Both A and B is correct
• A is correct , but B is not

What does the following relational operation perform?ρ x(A1,A2,A3…) (E)

• It returns the result of expression E with the previous attribute names
• It returns the result of expression E renaming the attributes as A1, A2, … and Relation with x
• It returns the result of the relation E with x only
• None of the mentioned

Relational Algebra is a __________ query language that takes two relations as input and produces another relation as an output of the query.

• Relational
• Structural
• Procedural
• Fundamental