Database Management System 2019 MCA 4th Sem RCA401 AKTU

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Paper Id: 214237Roll No. _____________________

MCA(SEM IV) THEORY EXAMINATION 2018-19

DATABASE MANAGEMENT SYSTEMS

Time: 3 Hours Total Marks: 70

Note: Assume any Missing Data.

SECTION A

1. Attempt all questions in brief. 2 x 7 = 14

    (a) Differentiate between simple attributes and composite attributes.

    (b) What is total and partial participation of any entity set E in a relationship set R ?

    (c) Write Anomalies with Interleaved Execution of a transaction.

    (d) What is multi version protocol ?

    (e) Define multi valued dependency.

    (f) Differentiate Deferred Vs Immediate database modification.

    (g) Prove that if in a relational schema, the no of attributes in a primary key is one, the schema will be at least in 2NF.

SECTION B

2. Attempt any three of the following: 7 x 3 = 21

    (a) Explain the concept of referential integrity and foreign key with suitable example.

    (b) What are Relational Model Mapping Cardinalities ? Give example for each cardinalities used in DBMS.

    (c) Explain Cursors, Sequence and Procedures used in SeL.

    (d) Consider the relations:

          PROJECT (proj #, proj_name, chief architect)

          EMPLOYEE (emp#, emp_name)

          AS SIGNED (proj#, emp_name)

          Use relational algebra to express the following queries:

          (i) Get details of employees working on projects.

          (ii) Get the employee number of employees who work on all projects.

          (iii) Get details of project on which employee with name ‘RAM’ is working.

    (e) A transaction is failed and enters aborted state. Mention the conditions under which we can restart the transaction and kill the transaction.

SECTION C

3. Attempt any one part of the following: 7 x 1 = 7

    (a) A set of FD’s for the relation R-{A, B, C, D, E, F} is AB→C, C→A, BC→D, ACD→B, BE→C, EC→FA, CF→BD, F→E: Find a Canonical cover for this set.

    (b) Suppose that we decompose the schema R(A, B, C, D, E) into R1 and R2 as R1:{A, B, C} R2:{C, D, E} justify whether it is lossless decomposition or not.

4. Attempt any one part of the following: 7 x 1 = 7

    (a) A transaction is failed and enters aborted state. Mention the conditions under which we can restart the transaction and kill the transaction.

    (b) Normalize the given relation up to 3NF: R:{A, B, C, D}, F={AB→D, AC→BD, B→C}

5. Attempt any one part of the following: 7 x 1 = 7

    (a) Write short notes on following

          (i) Lock Based Protocols

          (ii) Deadlock Prevention Protocols

          (iii) Concurrency control in Distributed System

    (b) In an organization several projects are undertaken. Each project can employ one or more employees. Each employee can work on one or more projects. Each project is undertaken on the request of client. A project can use a number of items and item may be used by several projects. Draw an E-R diagram and convert it to a relational schema.

6. Attempt any one part of the following: 7 x 1 = 7

    (a) What is deadlock ? Discuss any one deadlock detection algorithm in database transaction processing.

    (b) What is the system log used for ? What are the typical kinds of records in a system log ? What are transaction commit points, and why they important ?

7. Attempt any one part of the following: 7 x 1 = 7

    (a) What are different locking techniques for concurrency control ?

    (b) Describe multi-version concurrency control. What are its benefits and disadvantages in comparison to locking ?

Thank You!