2011dbms
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This document contains questions for a database engineering examination. It includes questions about data definition language commands, differences between file processing systems and database systems, weak entity sets, cardinality, foreign keys, hashing techniques, lock types, differences between object-oriented and object-relational databases, rollup, entity-relationship modeling, converting models, B+ tree operations, relational algebra queries, relational calculus queries, SQL queries, and more. Students are asked to answer one compulsory question with multiple parts, and five questions from the remaining list.
2011dbms
- 1. PGCS 4205 Fourth Semester Examination - 2011 DATABASE ENGINEERING Full Marks - 70 Time:3 Hours Answer Question No. 1 which is compulsory and any five from the rest. The figures in the right-hand margin indicate marks. 1. ,.74nswer the following questions : / / , 1a1 Give two examples of DCL. 2x1O (b) ist four significant differences between a file processing system and a : (c) Give an example of a weak entity set and explain why it is weak. .l (d) What is cardinality ? How many types of cardinality are available ? , ,'r (f) Define foreign key. Write an example to explain it. _ (g) Write down four differences between static hashing and dynamic hashing. '. (h) Distinguish between shared lock and exclusive lock. (i) What is the difference between object oriented and objeci relational data- base ? Give an example. .0) What do you mean by rollup ? Explain using an example. " 2 fta) More than one teacher can teach a course. A student can register to -/''/ ,f, any one teacher for the course. Draw the ER diagram and convert it to Relationalmodel. 5 (b) How to convert a network model to relational model ? Explain using an example. 5 P.T.O.
- 2. 3. How to insert, delete and update a B+ tree ? Explain usin$ example. 10 +. ..'(a)@) "zeonsider the following relations : r-/ ^a , ,,^-/ Student (Rollno, Name, Subject, Marks) Teacher (Tid, Tname, Subject, Rollno) Write the following queries in relational aigebra : (i) Find the name of those students who have registered with teacher 001. (ii) Find the name of those teachers who have more than 5 registered students. (b)r,Aonsiderthe following relations : 5 '/ EMPLOYEE (Emp_Code, Emp_Name, Desig, Mgr_No, Doj, Salary, Comm, Dept_Code) DEPARTM ENT (Dept_Code, Dept_Name, Location) Write the following queries in relational calculus : (i) Find the name and Emp-Code of all employees who work for the ' "Computer Science" Depadment. (ii) Find the name of all employees whose salary is above Rs. 25000i- along with their department name. 5. (a) Considerthefollowing relations. 5 ' Student (Rollno, Name, Subject, Marks) Write the following queries in SeL : (i) Find the name of those students who have secured more that the . average marks in the class ? (ii) Find the name of those students who have secured the highest mark in each subject ? (b) Considerthe following relations : 5 Student (Rollno, Name, Subject, Marks) Teacher (Tid, Tname, Subject, Rollno) Write the following queries in eBE : (i) Find the name of those students who have registered with teacher 001 . (ii) Find the name of those students who have secured the highest mark in the class ? PCCS 4205 Contd.
- 3. 6. (a) Explain Multivalued dependency with examples. 5 (b) Considerthe following relations : 5 Student (Rollno, Name, Subject, Marks) Teacher (Tid, Tname, Subject, Rollno) Draw the relational algebra tree forfinding the name of those students who have registered with teacher 001. Find the costs associated with various operations involved in the above query and write a process to optimize it. (a) What is Serialize ? Give some examples for testing of Serializability. 5 (b) What is timestamp ? Explain with examples. 5 Write short notes on any two of the following : 5x2 (a) Data lndependence (b) RA|D (c) Thomas Write Rule (d) Phantom rows.