SSC CGL - DBMS 1000+ MCQ [Solved] PDF Download

1. Create a table with the following attributes: Employee(EMPNO integer, EMPNAME of 10 characters)
A. Create table Employee(EMPNO int, EMPNAME char(10));
B. Create table Employee(EMPNO integer, EMPNAME String(10));
C. Create table Emplo(EMPNO number, EMPNAME string);
D. Create table Emp(EMPNO int, EMPNAME char(10));
Answer : A

2. Cascading rollback is avoided in all protocol except
A. strict two-phase locking protocol.
B. tree locking protocol
C. two-phase locking protocol
D. validation based protocol.
Answer : D

3. E-R Modeling is achieved by using ____ diagrams
A. DFD
B. Flowcharts
C. Gantt Charts
D. E-R
Answer : D

4. For correct behaviour during recovery, undo and redo operation must be
A. Commutative
B. Associative
C. idempotent
D. distributive
Answer : C

5. The graphical representation of a query is .
A. B-Tree
B. graph
C. Query Tree
D. directed graph
Answer : C

6. Use of UNIQUE while defining an attribute of a table in SQL means that the attribute values are
A. distinct values
B. cannot have NULL
C. both (A) & (B)
D. same as primary key
Answer : C

7. In an ER diagram the ___shape specifies the Attibute and a ____ shape specifies the primary key attribute.
A. Oval; An oval with an underlined attribute
B. Circle; A circle with bolded attribute inside it
C. Diamond; A bolded attribute
D. Square; An attribute within the square
Answer : A

8. Tree structures are used to store data in
A. Network model.
B. Relational model.
C. Hierarchical model.
D. File based system.
Answer : C

9. Which of the following constitutes a basic set of operations for manipulating relational data?
A. Predicate calculus
B. Relational calculus
C. Relational algebra
D. SQL
Answer : C

10. ………………… approach reduces time and effort required for design and lesser risk in database management.
A. Single global database
B. Multiple databases
C. Top-down approach
D. None of the above
Answer : B

11. Change Staff table by removing default of Assistant for position column
A. ALTER TABLE Staff ALTER position DROP DEFAULT;
B. ALTER TABLE Staff ALTER position DEFAULT;
C. ALTER TABLE Staff ALTER DROP DEFAULT;
D. MODIFY Staff ALTER position DROP DEFAULT;
Answer : A

12. The ______ key of a relation is the attribute (column) or collection of attributes, which uniquely identify a given tuple.
A. Primary
B. Foreign
C. Candidate
D. Alternate
Answer : A

13. ______contains information that defines valid values that are stored in a column or data type.
A. Default
B. Index
C. Rule
D. View
Answer : B

14. In an ER model,_____ is described in the database by storing its data.
A. Entity
B. Attribute
C. Relationship
D. Notation
Answer : A

15. Consider the join of relation R with a relation S. If R has m tuples and S has n tuples, then the maximum and minimum size of the join respectively are
A. m+n and 0
B. m+n and |m-n|
C. mn and 0
D. mn and m+n
Answer : C

16. The _____ category includes storage media that can be operated on directly by the computers central processing unit.
A. Primary storage
B. Secondary Storage
C. All
D. Tertiary Storage
Answer : A

17. If a transaction T has obtained an exclusive lock on item Q, then T can
A. read Q
B. write Q
C. both read and write Q
D. write Q but not read Q
Answer : C

18. It is an abstraction through which relationships are treated as higher level entities
A. Generalization.
B. Specialization.
C. Aggregation.
D. Inheritance.
Answer : C

19. Given the following relation S(SNO,SNAME,CITY) write a query to update the value of CITY to KANPUR for the supplier S1.
A. UPDATE S CITY = KANPUR WHERE SNO=S1
B. UPDATE S SET CITY = KANPUR FOR SNO=S1
C. UPDATE S SET CITY = KANPUR WHERE SNO=S1
D. UPDATE S RENAME CITY = KANPUR WHERE SNO=S1
Answer : C

20. _____ First proposed the process of normalization.
A. Edgar. W
B. Edward Stephen
C. Edgar F. Codd
D. Edward Codd
Answer : C

21. In E-R Diagram total participation is represented by
A. Double lines
B. Single line
C. Dashed lines
D. Triangle
Answer : A

22. According to the levels of abstraction, the schema at the intermediate level is called
A. Logical schema.
B. Physicl schema.
C. Subschema.
D. None of the above.
Answer : D

23. _______ product was acquired by Informix, integrated into its RDBMS and introduced as the Informix Universal Server an ORDBMS.
A. Star
B. llustar
C. SQL
D. Cygnus
Answer : B

24. For using a specific database …………… command is used.
A. use database
B. database name use
C. Both A & B
D. None of them
Answer : A

25. If both the functional dependencies : X�Y and Y�X hold for two attributes X and Y then the relationship between X and Y is
A. M:N
B. M:1
C.
D. 1:M
Answer : C

26. ______is a special type of integrity constraint that relates two relations & maintains consistency across the relations.
A. Domain Integrity Constraints
B. Referential Integrity Constraints
C. Domain Constraints
D. Entity Integrity Constraints
Answer : B

27. Between DRAM and magnetic disk storage another form of memory, called ______ memory is becoming common because it is non volatile.
A. RAM
B. Flash
C. Hard Disk
D. Secondary
Answer : B

28. Maximum height of a B+ tree of order m with n key values is
A. Logm(n)
B. (m+n)/2
C. Logm/2(m+n)
D. None of these
Answer : D

29. A list consists of last names, first names, addresses and pin codes. If all people in the list have the same last name and same pin code a useful key would be
A. the pin code
B. the last name
C. the compound key first name and last name
D. Tr from next page
Answer : C

30. In SQL, testing whether a subquery is empty is done using
A. DISTINCT
B. UNIQUE
C. NULL
D. EXISTS
Answer : D

31. What is a disjoint less constraint?
A. It requires that an entity belongs to no more than one level entity set.
B. The same entity may belong to more than one level.
C. The database must contain an unmatched foreign key value.
D. An entity can be joined with another entity in the same level entity set.
Answer : A

32. A relation is in attribute of other composite key. if an attribute of a composite key is dependent on an
A. 2NF
B. 3NF
C. BCNF
D. 1NF
Answer : B

33. The ____ operator joins two or more conditions and displays rows only if that rows data satisfies all conditions specified.
A. OR
B. AND
C. NOT
D. ALL
Answer : B

34. Manager salary details are hidden from the employee .This is
A. Conceptual level data hiding.
B. External level data hiding.
C. Physical level data hiding.
D. None of these.
Answer : A

35. Key to represent relationship between tables is called
A. primary key
B. secondary key
C. foreign key
D. none of the above
Answer : C

36. Which two files are used during operation of the DBMS?
A. Query languages and utilities
B. DML and query language
C. Data dictionary and transaction log
D. Data dictionary and query language
Answer : C

37. The fact that information in the data warehouse changes far less often and may be regarded as non-real-time with periodic updating; This implies that data warehouses are _______
A. Volatile
B. Non - Volatile
C. Logical
D. Physical
Answer : B

38. Immediate database modification technique uses
A. Both undo and redo.
B. Undo but no redo.
C. Redo but no undo.
D. Neither undo nor redo.
Answer : A

39. A _____ is used to define overall design of the database
A. code
B. data definition language
C. application program
D. schema
Answer : D

40. ______defines the structure of a relation which consists of a fixed set of attribute-domain pairs.
A. Instance
B. Program
C. Schema
D. Super Key
Answer : C

41. In b-tree the number of keys in each node is than the number of its children.
A. one less
B. same
C. one more
D. half
Answer : A

42. Which of the syntax is correct for insert statement?
i) insert into values
ii) insert into (column list) values
A. i-only
B. ii-only
C. Both of them
D. None of them
Answer : C

43. Relational Algebra is
A. Data Definition Language .
B. Meta Language
C. Procedural query Language
D. None of the above
Answer : C

44. Precedence graphs help to find a
A. Serializable schedule.
B. Recoverable schedule.
C. Deadlock free schedule.
D. Cascadeless schedule.
Answer : A

45. The default level of consistency in SQLis
A. repeatable read
B. read committed
C. read uncommitted
D. serializable
Answer : D

46. Which of the following is not a property of transactions?
A. Atomicity
B. Concurrency
C. Isolation
D. Durability
Answer : B

47. The concept of mapping of ______ entity types is the concept in which the for each strong entity type E in the ER schema, create a relation R that includes all the simple attributes of E.
A. Regular
B. Irregular
C. None
D. Weak
Answer : A

48. The one guideline to be followed while designing the database is
A. A database design may be ambiguous.
B. It should avoid/reduce the redundancy.
C. Unrelated data should be in the same table so that updating the data will be easy.
D. An entity should not have attributes.
Answer : B

49. DBMS is a collection of _____ that enables user to create and maintain a database.
A. Keys
B. Program
C. Translators
D. Language Activity
Answer : B

50. The rule that a value of a foreign key must appear as a value of some specific table is called a
A. Referential constraint.
B. Index.
C. Integrity constraint.
D. Functional dependency.
Answer : A