Database Systems and Applications MCQ Questions & Answers

Database Systems and Applications MCQ Questions & Answers

Quiz – 3

1. The entity involved in the generalization is considered as
   a. Medium Class of entity
   b. Mini Class of entity
   c. Subclass of entity
   d. Super class of entity
2. The operations of Natural-join in databases are
   a. Distributive
   b. Commutative
   c. Conjunctive
   d. Associative
3. Identify correct option for below SQL statement Select Cust_id from Customer where cust_id NOT IN ( select cust_id from Company );
   a. View all the customers from Customer table and NOT from Company table
   b. View all the customers from Customer table who does not have Company
   c. View all the customer from Customer and Company tables
   d. View all the customer from Company table only
4. Which normal form is considered adequate for normal relational database design?
   a. 4NF
   b. 5NF
   c. 2NF
   d. 3NF
   

   
   
   
   

5. If each functional dependency X→Y specified in F either appeared directly in one of the relation schemas Ri in the decomposition D or could be inferred from the dependencies that appear in some Ri.This property is called ______
   a. Attribute preservation condition
   b. Dependency preservation condition
   c. Decomposition condition
   d. Lossless Join condition
6. The rule that specifies removal of attributes from the right-hand side of a dependency
   a. Reflexive rule
   b. Augmentation rule
   c. Decomposition rule
   d. Transitive rule
7. The situation in which a bucket may overflow even when other buckets still have space is called
   a. bucket surplus
   b. bucket skew
   c. bucket overflow
   d. bucket spill 
8. Which of the following is not an indexing method?
   a. Clustering
   b. Secondary
   c. None of the above
   d. Primary

   
   
   
   

9. Which type of SQL group is used to update and access control of the data in the database.
   a. DCL, DML
   b. DML, DDL
   c. DDL, DML
   d. DML, DCL
10. Which f the following is best suitable for DROP, DELETE and Truncate Command.
     a. Drop used to delete the entire table , Delete is used to delete the data of table and Truncate is used to delete the entire table.
    b. Drop used to delete the complete data inside the table, Delete is used to delete the table records and Truncate is used to delete the entire table.
    c. Drop used to delete the entire table, Delete is used to delete the table records and Truncate is used to delete the complete data inside the table.
    d. Drop used to delete the data, Delete is used to delete the entire table and Truncate is used to delete the complete data inside the table.
11. Primary Indexes are built on
     a. Structured file of records
    b. Non – ordered file of records.
    c. Unstructured file of records.
    d. Ordered file of records
    

12. Which statement would rename a column salary to new_salary in the table Employee which is already created?

    ALTER TABLE Employee rename COLUMN (salary NUMBER(3,1) TO new_salary);
    ALTER TABLE Employee rename salary NUMBER(3,1);
    ALTER TABLE Employee rename (salary NUMBER(3,1) TO new_ salary NUMBER(3,1));
    ALTER TABLE Employee rename salary TO new_salary;
    ALTER TABLE Employee rename COLUMN salary TO new_salary;

    a. 1, 4, 5
    b. 5
    c. 4, 5
    d. 1, 3
    

    
    
    
13. A single further allows the user to be authenticated once, and multiple applications can then verify the user’s identity through an authentication service without requiring reauthentication.
    a. Virtual Private Database (VPD)
    b. OpenID
    c. Sign-on system
    d. Security Assertion Markup Language (SAML)
14. DBMS periodically suspends all processing and synchronizes its files and journals through the use of
     a. Backup facility
    b. Recovery manager
    c. Checkpoint facility
    d. Database change log
15. The operations of Natural-join in databases are
     a. Associative
    b. All The Above
    c. Commutative
    d. Distributive Under Projection
16. Which of the following is used to provide delete authorization to instructor?
     a. CREATE ROLE instructor; GRANT SELECT ON takes TO instructor;
    b. CREATE ROLE instructor ; GRANT DELETE TO instructor;
    c. CREATE ROLE instructor; GRANT DELETE ON takes TO instructor;
    d. All of the mentioned
    
    
    
    

17. Even with two-factor authentication, users may still be vulnerable to_____________attacks.
     a. scripting
    b. Cross attack
    c. Man-in-the-middle
    d. Radiant
18. The Assessment plan for composite query involves many
     a. Disk Access
    b. Parameter Access
    c. All of the above
    d. Sector Access
19. Which of the following is an example of a self-referencing relationship?
     a. A “Product” table with a foreign key referencing the “Category” table.
    b. A “Category” table with a foreign key referencing the “Product” table.
    c. An “Employee” table with a foreign key referencing the “Department” table
    d. A “Department” table with a foreign key referencing the “Employee” table.
    
    
    
    
    

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Quiz – 2

1. Consider a disk with a sector size of 512 bytes, 2000 tracks per surface,50 sectors per track, five double-sided platters, and average seek time of 10 msec.? What is the capacity of the disk?
   a. 500000K
   b. 600000K
   c. 550000K
   d. 450000K
   
2. If a transaction obtains a shared mode lock on a data item Q, ____________.
   a. it can read Q but not modify Q
   b. it can read Q and write Q
   c. it cannot read Q but modify Q
   d. it can read and modify Q
3. i) Atomicity
   ii) Inconsistency Removal
   iii) Isolation
   iv) Durability
   In perspective of Desirable properties of transaction which of the following is true
   a. i),ii),iii) must always hold
   b. i),iii),iv) must always hold
   c. i),ii),iii),iv)must always hold
   d. i),ii),iv) must always hold
4. i) they belong to different transactions;
   ii) they access the same item X
   iii) at least one of the operations is a write_item(X)
   Which of the following is true if two transactions in a schedule are said to be conflicting in perspective of above three conditions
   a. If either of i),ii),iii) is true
   b. If all of i),ii),iii) are true
   c. If none of i),ii),iii) are true
   d. If any two of i),i),iii) are true
5. i) BEGIN_TRANSACTION
   ii) COMMIT_TRANSACTION
   iii) RELEASE_TRANSACTON
   iv)COMMIT_TRANSACTION
   If we are taking about transaction states which of the following is true
   a. i),ii),iv) are correct
   b. i),iii),iv) are correct
   c. ii),iii),iv) are correct
   d. i),ii), iii) are correct
6. Concurrency control is needed because
   a. The lost update problem
   b. All of the mentioned
   c. The incorrect summary problem
   d. The dirty read problem
7. A Web site that allows users to enter text, such as a comment or a name, and then stores it and later display it to other users, is potentially vulnerable to a kind of attack called a ___________ attack.
   a. Cross-site request forgery
   b. Cross-site scripting
   c. Two-factor authentication
   d. Cross-site scoring scripting
8. The grants privileges on SQL authorization mechanism does not have
   a. Specified tuples Entire relation
   b. Entire relation
   c. None of the above
   d. Specified attributes
   
   
   
   

9. Prevention of access to the database by unauthorized users is referred to as :
   a. Productivity
   b. Security
   c. Integrity
   d. Reliability
10. When we update any tuple in the relation which Authorization on a relation allows a user to?
    a. define authorization
    b. grant authorization
    c. select authorization
    d. update authorization
11. What is used for database security?
    a. a view
    b. all of the above
    c. data encryption
    d. finger print
12. To construct an XML document two main structuring concepts are used
    a. Data, Element
    b. Element, Attribute
    c. All of the above
    d. Data Information

    
    
    
    

13. By alerting the processing programme each time a start or end tag is encountered, this feature enables on-the-fly processing of XML documents
    a. DOM
    b. DDL
    c. DTD
    d. SAX
14. Data security threats include
    a. hardware protection
    b. all of the above
    c. privacy invasion
    d. fraudulent manipulation of data
15. ______ is an attack which forces an end user to execute unwanted actions on a web application in which he/she is currently authenticated.
    a. Cross-site scoring scripting
    b. Two-factor authentication
    c. Cross-site request forgery
    d. Cross-site scripting
16. Authentication refers to
    a. controlling access to portions of database
    b. all of the above
    c. controlling the operation on the data
    d. methods of restricting user access to system
    
    
    
    

17. Transaction processing is not associated with
    a. maintaining data
    b. producing detail, summary, or exception reports
    c. recording a business activity
    d. confirming an action or triggering a response
18. Select a query to update the portion of the address in the given employee table, within the address, house number ‘194’ will be replaced by ‘648’.
    a. UPDATE address_housenumber = REPLACE(address_housenumber, ‘194’, ‘648’);
    b. UPDATE employee SET address_housenumber = REPLACE(address_housenumber, ‘194’, ‘648’);
    c. UPDATE address_housenumber = REPLACE(address_housenumber, ‘194’, ‘648’) WHERE address_housenumber LIKE ‘%194%’;
    d. UPDATE employee SET address_housenumber = REPLACE(address_housenumber, ‘194’, ‘648’) WHERE address_housenumber LIKE ‘%194%’;
19. Consider a disk with a sector size of 512 bytes, 2000 tracks per surface,50 sectors per track, five double-sided platters, and average seek time of 10 msec. If the disk platters rotate at 5400 rpm (revolutions per minute), what is the maximum rotational delay?
    a. 0.011seconds
    b. 0.031 Seconds
    c. 0.12seconds
    d. 0.00099 seconds
    e. 0.00011seconds
20. Pick out the Odd Man out from the types of the closed hashing techniques
    a. Quadratic Probing & Linear Probing
    b. Double Hashing
    c. None of these methods
    d. Separate Chaining & Binary Probing

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Quiz – 1

1. Which is the lowest level of abstraction that describes how the data are actually stored?
   a. View
   b. User
   c. Abstract
   d. Physical
2. A weak entity
   a. Has 1:N relationship with its strong entity
   b. Does have a partial key
   c. All of the above
   d. Does not have a primary key
3. A social media platform allows users to create profiles and connect with other users. Users can post multiple photos, and each photo can have multiple tags associated with it. Additionally, users can follow other users. Identify the cardinalities in this scenario.
   a. User-to-Photo (one-to-many), Photo-to-User (many-to-many), User-to-User (many-to-many)
   b. Photo-to-Tag (many-to-many), User-to-Photo (one-to-many). User-to-Tag (many-to-many)
   c. User-to-Photo (one-to-many), Photo-to-Tag (many-to-many). User-to-User (many-to-many)
   d. Photo-to-User (one-to-many), Photo-to-Tag (many-to-one), User-to-User (many-to-many)
4. The weak entity set can be transformed into a strong entity set by
   a. using generalization
   b. adding appropriate attributes
   c. adding a relationship set
   d. using aggregation
   
   
   
   
5. A _________ entity does not have a primary key of its own.
   a Weak
   b. Regular
   c. Total participation type
   d. Partial relationship type
6. The following ER diagram is an example for
   a. Ternary relationship
   b. Recursive relationship
   c. Binary relationship
   d. No relationship
7. ___________ is a set of commands to support creation, deletion and modification of table structures and views.
   a. Data Definition Language
   b. Structure Query Language
   c. Data Manipulation Language
   d. Embedded Language
8. Relation R1 has 20 tuples and 6 attributes. Relation R2 has 0 tuples and 5 attributes. When CARTESIAN PRODUCT is applied between R1 and R2, how many tuples would the resultant set have?
   a. 30
   b. 0
   c. 100
   d. 20
   
   
   
   
9. A correlated subquery is
   a. A sub-query that does not depend on its outer query’s correlation names
   b. A sub-query that substitutes the names of the outer query
   c. An independent query that uses the correlation name of another independent query.
   d. A sub-query that uses the correlation name of an outer query
10. How can we control duplicate values in result using SQL query.
    a. Using group by
    b. Using Distinct keyword
    c. Using where clause
    d. Removing duplicate values
11. {ts & instructor (t[name] = s[name]^ 3 u t department (u[dept name] = s[dept name]^ u[building] = “Watson”))) Which of the following best describes the query?
    a. Finds the names of all department is in the Watson building
    b. Finds the names of all instructors whose department is in the Watson building
    c. Finds the name of the dapartment whose instructor and building is Watson
    d. Returns the building name of all the departments
12. Identify the CORRECT statement about TRIVIAL FD
    a. Trivial FD is one where every attribute on the RHS is also on the LHS.
    b. Trivial FD is one where the RHS is a subset of the LHS
    c. None
    d. Every FD represents a Trivial FD
    
    
    
    
13. Multivalued Dependencies are a consequence of
    a. First Normal Form
    b. Fourth Normal Form
    c. Second Normal Form
    d. Third Normal Form
14. When you normalize a relation by breaking it into two smaller relations, what must you do to maintain data integrity?
    a. Assign both relations the same primary key field(s)
    b. Create a primary key(s) for the new relation
    c. Remove any functional dependencies from both relations
    d. Create a foreign key for the new relation
15. Which of the following statements fully describes data in 2NF?
    a. When any repeating fields have been removed and the table is given a primary key
    b. When all repeating entries of data are removed and the fields in each table are directly related to the primary key and no fields are present that are not related to each other
    c. When all the fields in each table are directly related to the primary key
    d. If and only if it is in 2NF and every non-key attribute is Non-transitively dependent on the primary key
16. Neither multivalued nor composite attributes, nor their combinations, may be used in the
    a. First
    b. Third
    c. Second
    d. fourth
    
    
    
    
17. Which is the lowest level of abstraction that describes how the data are actually stored?
    a. Abstract
    b. View
    c. Physical
    d. User
18. What is a database management system?
    a. Collection of interrelated data
    b. None of the above
    c. Collection of many programs to manage data
    d. Collection of Commands
19. What is rows of a relation known as?
    a. Data
    b. Tuple
    c. Degree
    d. Entity
20. A DB is a large collection of
    a. Files
    b. Sectors
    c. Records
    d. Fields

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