Closure

Which type of anomaly occurs when adding new data to a database causes unintended changes to existing data?

•    A) Insertion anomaly 

•    B) Deletion anomaly 

•    C) Update anomaly 

•    D) Redundancy anomaly

Which normal form is designed to eliminate insertion, deletion, and update anomalies?

• A) First Normal Form (1NF) 

•    B) Second Normal Form (2NF) 

•    C) Third Normal Form (3NF) 

•    D) Boyce-Codd Normal Form (BCNF) 

A university database contains a relation `StudentCourses` with attributes `(StudentID, CourseID, Grade)`. The database administrator notices that when a student drops a course, it leads to deletion anomalies where the student's record is completely removed. Which type of anomaly is observed in this scenario?

•    A) Insertion anomaly 

• B) Deletion anomaly 

• C) Update anomaly 

•    D) Dependency anomaly

An e-commerce database maintains a relation `OrderDetails` with attributes `(OrderID, ProductID, Quantity)`. When a product's quantity changes, the database administrator notices that updating this information requires modifying multiple records, leading to inconsistencies. Which type of anomaly is evident here?

•    A) Insertion anomaly 

•    B) Deletion anomaly 

• C) Update anomaly 

•    D) Dependency anomaly

In a manufacturing database, a relation `ProductInventory` has attributes `(ProductID, WarehouseID, Quantity)`. The database designer realizes that adding a new product to the inventory without assigning it to any warehouse is not allowed due to missing warehouse ID. Which type of anomaly is being prevented in this case?

•    A) Insertion anomaly 

•    B) Deletion anomaly 

•    C) Update anomaly 

•    D) Dependency anomaly

A database system uses a relation `EmployeeSalary` with attributes `(EmployeeID, Salary)`. The database administrator notices that updating an employee's salary in multiple records every year is cumbersome and error-prone. Which type of anomaly is associated with this scenario?

•    A) Insertion anomaly 

•    B) Deletion anomaly 

•    C) Update anomaly 

•    D) Dependency anomaly

A library database maintains a relation `BookLoans` with attributes `(BookID, MemberID, DueDate)`. When a member returns a book, the database administrator observes that deleting the corresponding record affects the book and member details. Which type of anomaly is evident here?

•     A) Insertion anomaly 

•     B) Deletion anomaly 

•     C) Update anomaly 

•     D) Dependency anomaly

Let R(A,B,C,D) be a relation schema and F = {A->BC, AB->D, B->C} be the set of functional dependencies defined for R. Which will represent the closure of attribute set {B}?

• (A) (A,C,D)

• (B) (B,C)

• (C) (A,B,C)

• (D) (C,B)

•   (E) (B)

Following are the functional dependencies for relation R(PQRSTU):

PQ->RS, ST->U, R->T, U->S, PT->R and T->P

Which of the following is TRUE?

• (A) (PQ)+ = (PRST)

• (B) (ST)+ = (PQRSTU)

• (C) (QT)+ = (PQRSTU)

• (D) (PQ)+ = (PQRTU)

Let FD’s be A->BC, AB->D, B->C this defined over a relation R. Which of these represents the closure of attribute B?

• (A) (A,C,D)

• (B) (B, C)

• (C) (A,B,C)

• (D) (B)