Showing posts with label Database Quizzes. Show all posts
Showing posts with label Database Quizzes. Show all posts

Thursday, 3 March 2016

Database management systems quiz questions with answers 1

DBMS quiz with answers / Database Management Systems Basics Quiz / DBMS Multiple choice questions


Quiz


1. The row/tuple of a relational table is called as an entity _________.
(a) Instance
(b) Attribute
(c) Model
(d) Relationship
2. Relational calculus is a ________
(a) Procedural language
(b) Non-Procedural language
(c) Data Definition language
(d) High level language
3. SQL is a _____________
(a) Procedural language
(b) Non-Procedural language
(c) Data Definition language
(d) High level language
4. Cartesian product (X) operation in relational algebra is ________
(a) an unary operator
(b) a binary operator
(c) both (a) and (b)
(d) not an operator
5. A database schema can be written in ________
(a) DML (Data Manipulation Language)
(b) DDL (Data Definition Language)
(c) DCL (Data Control Language)
(d) TCL (Transaction Control Language)
6. Which of the following is the advantage of relational database model?
(a) Structural dependence
(b) Conceptual complexity
(c) Complex database design
(d) Easier database design
7. A relational database management system is a single data repository in which data _______ is maintained.
(a) independence
(b) dependence
(c) complexity
(d) None of the above
8. Relational algebra is a _________
(a) Procedural language
(b) Non-Procedural language
(c) Data Definition language
(d) High level language
9. Which of the following is the external level of database architecture?
(a) Physical level
(b) Logical level
(c) View level
(d) All of the above
10. An entity set that does not have enough _________ to form a _______ is a weak entity set.
(a) attribute, primary key
(b) records, foreign key
(c) records, primary key
(d) attribute, foreign key



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Wednesday, 24 February 2016

Fragmentation in Distributed Database - Quiz

Database System Architectures - Quiz


1. What are the advantages of Replication of data in Distributed database?
    Avaliability, Parallelism, Increased data transfer
    Availability, Parallelism, Reduced data transfer
    Availability, Increased parallelism, Cost of updates
    All of the above

2. A fragmentation technique wherein every tuple of a table is assigned to one or more fragments as a result of fragmentation is called ________________ .
    Vertical Fragmentation
    Horizontal Fragmentation
    Hybrid Fragmentation
    None of the above

Assume a relation EMP as given below:
                EMP(EmpNo, EName, Job, Sal, Department)
Furthermore, assume that there are two applications which are accessing the above mentioned table. One application typically retrieves information about employees who earn more than Rs5.000, the other application typically manages information about 'clerks' (job). Also, assume that there are employees with other designations and different salaries stored in EMP. With this information, answer the questions 3 to 6.

3. Which of the following are the simple predicates which can be directly extracted from the given applications?
    {Job = clerk, Salary>5000}
    {Job = clerk, Salary<5000 br=""> {Job = Manager, Salary>5000}
    {Job = Manager, Salary<5000 ul="">
    4. How many valid minterm predicates we can derive for the above said problem?
      4
      5
      3
      2

    5. Assume that the departments are 'Finance', 'Production', and 'Design'. If there is one more application which accesses the informatoin frequently based on the 'Finance' department, what would be the number of valid minterm fragments?
      5
      6
      7
      8

    6. If by mistake, I miss one of the valid minterm fragments. What would be the effect of that in fragmentation?
      Causes skew
      Reconstruction of EMP will be unsuccessful
      Slows down the database access
      None

    7. Which of the following failures are unique to distributed database systems?
      Failure of a site
      Loss of messages
      Network Partition
      All the above

    8. For the given set of simple predicates Pr, how many min-term predicates we can derive (including invalid ones). Pr = {Branch = “Vellore”, Branch = “Chennai”, Salary <=20000, Salary > 20000} Assumptions: Consider there are five different branches.
      4
      8
      16
      32

    9. In a distributed database application, if we have very many number of read only queries than update queries then ______________ allocation technique is advantageous.
      Hybrid Fragmentation
      Horizontal Fragmentation
      Replication
      Vertical Fragmentation

    10. Which of the following would be the advantage of Database Fragmentation?
      Most of the operations are local to any sites
      Reduced Network Traffic
      Parallel processing
      All the above

    Score =

    Correct answers:

Saturday, 20 February 2016

Database Management Systems - Relational Algebra quiz

Database management system quiz - DBMS quiz with answers - DBMS multiple choice questions - DBMS basics quiz - DBMS interview questions - Relational Algebra quiz in DBMS - Relational Algebra operations in Database interview questions



Let us use the following relations R and S to answer the questions 1 – 10s;
A
B
3
3
6
4
2
3
3
5
3
6
B
C
D
5
1
6
3
3
5
4
3
1
1. Compute R S. Which of the following records will be in the result? Assume each record has the schema (A, B, C, D).
(a) (3, 3, 1, 6)
(b) (6, 4, 4, 1)
(c) (2, 3, 3, 5)
(d) (3, 5, 3, 1)
2. Compute R R.A<S.C S. [this is theta join]. Which of the following records will be in the result? Assume each record has the schema (A, B, C, D).
(a) (2, 3, 3, 5)
(b) (6, 4, 4, 1)
(c) (6, 4, 3, 1)
(d) (3, 5, 1, 6)
3. Compute R R.B < S.D AND R.A<S.C S. [this is theta join]. Which of the following records will be in the result? Assume each record has the schema (A, B, C, D).
(a) (3, 3, 3, 5)
(b) (6, 4, 3, 1)
(c) (2, 3, 3, 5)
(d) (3, 5, 1, 6)
4. Compute π C, D (S). Which of the following records will be in the result?
(a) (5, 1)
(b) (4, 3)
(c) (3, 3)
(d) (3, 5)
5. Compute π B, C (R S). Which of the following records will be in the result?
(a) (6, 4)
(b) (4, 3)
(c) (5, 1)
(d) (5, 3)
6. Compute π B (R) - π B (S). Which of the following records will be in the result?
(a) (6)
(b) (4)
(c) (1)
(d) (5)
7. Compute π B (R) ∩ π B (S). Which of the following records will be in the result?
(a) (6)
(b) (1)
(c) (2)
(d) (5)
8. Compute R S. Which of the following records will be in the result? Assume each record has the schema (A, B, C, D).
(a) (3, 3, 1, 6)
(b) (6, 4, 4, 1)
(c) (3, 5, 1, 6)
(d) (3, 5, 3, 1)
9. Compute π B (R) U π B (S). Which of the following records will be in the result?
(a) (6)
(b) (1)
(c) (2)
(d) (5)
10. Assume a relation R(A, B) with n unique records, and a relation S(B, C) with m unique records. When you compute the natural join between R and S you shall get r records as the result. Which of the following assumptions are correct in terms of (n, m, r)?
(a) (5, 4, 25)
(b) (2, 3, 8)
(c) (3, 3, 10)
(d) (2, 3, 6)





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