Code No. : 9919 Sub. Code : HCAM 35

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1 Reg. No. :... Sub. Code : HCAM 35 M.C.A. (CBCS) DEGREE EXAMINATION, APRIL Third Semester Computer Applications DATABASE MANAGEMENT SYSTEMS (For those who joined in July 2012 onwards) Time : Three hours Maximum : 75 marks SECTION A (10 1 = 10 marks) Answer ALL questions. Choose the correct answer : 1. A relational database developer refers to a record as (a) a criteria a relation (c) a tuple (d) an attribute

2 2. An advantage of the database management approach is (a) (c) (d) data is dependent on programs data redundancy increases data is integrated and can be accessed by multiple programs none of the above 3. Functional dependencies are a generalization of (a) (c) (d) key dependencies. relation dependencies database dependencies none of these 4. Which is not a component of a relational database (a) entity attribute (c) table (d) hierarchy 5. In normal form, any multi-valued attributes have been removed. (a) First Second (c) Third (d) Fourth Page 2

3 6. A language that is used to specify the database schemethrough set of definitions is called (a) SQL OML (c) DDL (d) ISO 7. SQL is a type of language. (a) Low level High level (c) procedural (d) Non procedural 8. The role of the query system is to (a) (c) (d) present the data in a user friendly format provide data security retrieve and manipulate data support data integrity 9. Which component of the database management system (DBMS) most affects the performance (speed)? (a) (c) (d) Data Storage Subsystem Database Engine Query Processor Security Subsystem Page 3

4 10. The database model that utilizes multiple tables interconnected through common attributes to store and manage information is called a (a) (c) (d) Class Database Matrix Database Network Database Relational Database SECTION B (5 5 = 25 marks) Answer ALL questions, choosing either (a) or, each answer should not exceed 250 words. 11. (a) Explain the components of a storage manager. List down and explain database users. 12. (a) Explain functional dependency with example. Explain the aggregate functions in SQL. 13. (a) Explain with example hash index. What are A.C.I.D. properties? Page 4

5 14. (a) Explain table inheritance under object-based databases. What are the reasons for building distributed database system? 15. (a) Consider the following employee database : employee(employee_name,street,city) works(employee_name,company_name, salary) company(company_name,city) manages(employee_name, manager_name) Give an expression in SQL for each of the following queries : (i) (ii) find all employees who earn more than the average salary of all employees of their company. find all employees who live in the same cities as the companies for which they work. Page 5

6 Consider the following relational schema Person(driver_id, name, address) Car(license,model,year) Accident(report-number,date,location) Owns(driver_id, license) Participated(driver_id,car,report_nurnber, damage_amount) Construct the following SQL queries : (i) (ii) find the number of accidents in which the car belonging to John involved. update the damage amount for the car with license number ccdd12345 in the accident with report number R12345 to Rs SECTION C (5 8 = 40 marks) Answer ALL questions, choosing either (a) or, each answer should not exceed 600 words. 16. (a) Compare and contrast file oriented approach with that of database oriented approach. List down and explain various data models. Page 6

7 17. (a) Explain fourth normal form and domain key normal form with example. Explain with examples basic structure of SQL queries. 18. (a) Explain two-phase locking protocol in concurrency control. Explain multi level indices with example. 19. (a) Explain with example structured types and inheritance in SQL in object based databases. Discuss about concurrency control in distributed databases. 20. (a) Consider the following relational schema : employee(emp_no,emp_name,bdate,address sex,salary,dno) primary key : emp_no Page 7

8 Department(dnumber,dname) primary key: dnumber Project(pnumber,pname,plocation,dnum) primary key : pnumber works_on(empcode,pno,hours) primary key: (empcode,pno) Using above tables write SQL queries for the following : (i) Retrieve the name of each employee who works on all the projects controlled By department number 5. (ii) For each project on which more than two employees work, retrieve the Project number, project name, and the number of employees who work On the project. (iii) Retrieve a list of employees and the projects they are working on, ordered by Department and within each department, alphabetically by employee name. Page 8

9 (iv) For each department, retrieve the department number, the number of Employees in the department and their average salary. Consider the following relational schema : customer(customer_name,street,city) customer_name primary key branch(branch_name,branch_city,assets) branch_name primary key account(account_number,branch_name, balance) account_number primary key depositor(customer_name,account_number) primarykey(customer_name,account_ number) Using the above tables, Write SQL queries for the following : (i) (ii) Find all customers who have at most one account at Salem branch. Find the average balance for each customer who lives in Chennai and have atleast three accounts. Page 9

10 (iii) Find the number of depositors for each branch. (iv) Find the average account balance at each branch. Page 10

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