DBMS THEORY SOME IMPORTANT QUESTIONS
UNIT-1
1. What is Data Independency in DBMS? Explain its types.
2. Difference between File System and DBMS
3. What is ER Diagram? Explain different Components of an ER Diagram with their
Notation. Also make an ER Diagram for Employee Project Management.
4. What is Data Abstraction? How the Data Abstraction is achieved in DBMS?
5. List the four functions of DBA.
6. Differentiate between physical and logical data independence
7. What is Aggregation. Difference between Aggregation and Generalization
8. Draw and explain DBMS Structure.
9. Numerical on Reduction of an ER Diagrams to Tables.
10. Describe mapping constraints and its types.
11.Describe the concept of weak entity set.
12. Explain Keys and its types.
13.Describe the three-schema architecture. Why do we need mappings between
schema levels? How do different schema definition languages support this
architecture?
14.What are the different types of Data Models in DBMS? Explain them
UNIT-2
1.
Consider the following relational database schema consisting of the four relation
schemas:
passenger ( pid, pname, pgender, pcity)
agency ( aid, aname, acity)
flight (fid, fdate, time, src, dest)
booking (pid, aid, fid, fdate)
Evaluate the following questions using relational algebra queries
i)
Get the complete details of all flights to New Delhi.
ii)
iii)
Get the details about all flights from Chennai to New Delhi.
Find only the flight numbers for passenger with pid 123 for flights to Chennai
before 06/11/2020.
iv)
Find the passenger names for passengers who have bookings on at least one
flight.
v)
Find the agency names for agencies that located in the same city as passenger
with passenger id 123.
2. Determine cursors and its type. Also determine the purpose of following cursor
attributes: %FOUND, %ISOPEN, %NOTFOUND, and %ROWCOUNT.
3. Questions on SQL Queries and Relational Algebra
4. What is the difference between DROP and DELETE command?
5. What are Joins? Discuss all types of Joins with the help of suitable examples.
6. Consider the following schema for institute library:
Student (RollNo, Name, Father_ Name, Branch)
Book (ISBN, Title, Author, Publisher)
Issue (RollNo, ISBN, Date-of –Issue)
Write the following queries in SQL and relational algebra:
(i) List roll number and name of all students of the branch ‘CSE’.
(ii) Find the name of student who has issued a book published by ‘ABC’ publisher.
(iii) List title of all books and their authors issued to a student ‘RAM’.
(iv) List title of all books issued on or before December 1, 2020.
(v) List all books published by publisher ‘ABC’
7. Which relational algebra operations require the participating tables to be union
compatible? Give the Reason.
8. State the procedural DML and nonprocedural DML with their differences.
9. What is Aggregate Function in SQL? Write SQL query for different Aggregate
Function.
10.Explain Procedure in SQL/PL SQL
11. Discuss the DDL and DML Commands and its types.
12.What is Relational Calculus and its types.
13.What is Equi-Join in database?
14.What is a CLAUSE in terms of SQL?
UNIT-3
1. What is Functional Dependency? Explain the procedure of calculating the
Canonical Cover of a given Functional Dependency Set with suitable example. What
are advantages of normalization?
2. Consider the relation R(a,b,c,d) with Set F={a→c,b→d}. Decompose this relation
in 2 NF.
3. Explain the Loss Less Decomposition with example.
4. Describe Armstrong’s axioms in detail. What is the role of these rules in database
development process?
5. Describe the term MVD in the context of DBMS by giving an example. Discuss
4NF and 5NF also
6. What do you understand by transitive dependencies? Explain with an example
any two problems that can arise in the database if transitive dependencies are
present in the database.
7. (i) What is highest normal form of the Relation R(W,X,Y,Z) with the set F= { WY →
XZ, X →Y } (ii) Consider a relation R(A,B,C,D,E) with set F= { A→CD, C→B,B→AE}
What are the prime attributes of this Relation and Decompose the given relation in
3NF.
8. Given the following set of FDs on schema R (V,W,X,Y,Z) {Z→V, W→Y, XY→Z,
V→WX}State whether the following decomposition are loss-less-join
decompositions or not. (i) R1=(V,W,X) , R2=(V,Y,Z) (ii) R1=(V,W,X), R2=(X,Y,Z)
9. Explain BCNF with example.
10.
What is Distributed DBMS?
UNIT-4
1. Explain the method of testing the serializability. Consider the schedule S1 and S2
given below S1: R1(A),R2(B),W1(A),W2(B) S2: R2(B),R1(A),W2(B), W1(A) Check
whether the given schedules are conflict equivalent or not?
2. Describe serializable schedule. Discuss conflict serializability with suitable
example. Check the given Schedule S1 is Conflict Serializable or not? S1: R1(X),
R2(X),R2(Y),W2(Y),R1(Y),W1(X)
3. Explain Deadlock Handling with Suitable example.
4. Discuss the procedure of deadlock detection and recovery in transaction?
5. Consider schedules S1, S2, and S3 below. Determine whether each schedule is
strict, cascade less, recoverable, or non recoverable. (Determine the strictest
recoverability condition that each schedule satisfies.)
S1: r1 (X); r2 (Z); r1 (Z); r3 (X); r3 (Y); w1 (X); c1; w3 (Y); c3; r2 (Y); w2 (Z); w2 (Y); c2;
S2: r1 (X); r2 (Z); r1 (Z); r3 (X); r3 (Y); w1 (X); w3 (Y); r2 (Y); w2 (Z); w2 (Y); c1;c2; c3;
S3: r1 (X); r2 (Z); r3 (X); r1 (Z); r2 (Y); r3 (Y); w1 (X); c1; w2 (Z); w3 (Y); w2 (Y);c3; c2;
6. Consider the three transactions T1, T2, and T3, and the schedules S1 and S2given
below. State whether each schedule is serializable or not. If a schedule is serializable,
write down the equivalent serial schedule(s). T1: r1 (X); r1 (Z); w1 (X); T2: r2 (Z); r2
(Y); w2 (Z); w2 (Y); T3: r3 (X); r3 (Y); w3 (Y); S1: r1 (X); r2 (Z); r1 (Z); r3 (X); r3 (Y); w1
(X); w3 (Y); r2 (Y); w2 (Z); w2 (Y); S2: r1 (X); r2 (Z); r3 (X); r1 (Z); r2 (Y); r3 (Y); w1 (X);
w2 (Z); w3 (Y); w2 (Y);
7. What is a schedule? Define the concepts of recoverable, cascade less and strict
schedules, and compare them in terms of their recoverability.
8. List ACID properties of transaction. Explain the usefulness of each. What is the
importance of Log?
9. Classify the different states of a transaction with diagram.
10.
Examine the concept of View Serializability.
11.
Given a schedule S for transactions T1 and T2 with set of read and write
operations, S: R1(X) R2(X) R2(Y) W2(Y) R1(Y) W1(X). Identify, whether given schedule
is equivalent to serial schedule or not?
12.
Describe how view serializability is related to conflict serializability.
13.
When is a transaction Rolled Back?
14.
Explain Tree and Graph based Locking protocols.
UNIT-5
1. Explain Time Stamp Based Concurrency Control technique.
2. Explain Recovery from Concurrent Transaction.
3. Discuss 2 phase commit (2PC) protocol and time stamp based protocol with
suitable example. How the validation based protocols differ from 2PC?
4. What do you mean by time stamping protocol for concurrency controlling? Discuss
multi version scheme of concurrency.
5. How does strict timestamp ordering differ from basic timestamp ordering?
6. How do optimistic concurrency control techniques differ from other concurrency
control techniques? Why they are also called validation or certification techniques?
Discuss the typical phases of an optimistic concurrency control method.
7. Discuss the immediate update recovery technique in both single-user and
multiuser environments. What are the advantages and disadvantages of immediate
update?
8. Discuss Concurrency control. Why it is needed in DBMS?
9. Discuss Conservative 2PL (Static) and Strict 2PL.
10.
List the various levels of locking?
11.
Illustrate multiple granularity locking? How is it implemented?
12.
Illustrate timestamp protocol. In timestamp ordering w-timestamp (Q)
denotes the largest timestamp that executes write (Q) successfully. If we define it to
be timestamp of most recent transaction to execute write (Q) successfully. Is there
any difference? Justify your answer.