Database Management System 2072

Attempt all the questions.

1. Answer the following questions in short: (5x2=10)

    a)Three-schema architecture

    b) Advantage of DBMS approach over file system approach.

    c) What is weak entity, owner entity type and identifying relationship?

    d) Different types of data attributes.

    e) Differentiate between program-data independence and program-operation independence.

2. (a) Given an ER diagram for a database showing Bank. Each Bank can have multiple Branches, and each branch can have multiple accounts and loans. [6]

    (b) What is union compatibility? Define operations union, intersection, and difference on two union compatible relations R and S with suitable example.[4]

3. (a) Describe the different clauses in the syntax of an SQL query, and show what types of constructs can be specified in each clause.[5]

    (b) How view is defined in SQL? Explain the problems that may arise when one attempts to update a view. [1+4]

4. (a) Define Boyce-Codd normal form. How does it differ from 3NF? Why is it considered a stronger form of 3NF? [1+4]

    (b) What is a functional dependency? When are two sets of functional dependencies equivalent? How can we determine their equivalence? [1+4]

5. (a) Discuss the ACID properties of a database transaction with suitable example.[5]

    (b) Indicate how the recovery scheme works in a single user environment if the system fails

        i)After the transaction starts and before the read.

        ii)After the read and before the write.

        iii)After the write and before the commit.

        iv)After the commit and before al database entries are flushed onto disk.[5]

6. (a) What is the two-phase locking protocol? How does it guarantee serializability?[5]

    (b) What is meant by transaction rollback? What is meant by cascading rollback? Why do practical recovery methods use protocols that do not permit cascading rollback? [5]