Database Management System
MCQ For Gate Preparation
1. In an object-oriented model, one object can access data of another object by passing: a. Instance variable b. Message c. Variable d. None of these
2. A view of database that appears to an application program is known as: a. Schema b. Subschema c. virtual table d. none of the above
3. An abstraction concept for building composite object from their component object is called: a. Specialization b. Normalization c. Generalization d. Aggregation
4. A set of objects that share a common structure and a common behavior is called: a. Object b. Class c. Entity d. None of these
5. Every weak entity set can be converted into a strong entity set by: a. using generalization b. adding appropriate attributes c. using aggregation d. none of the above
6. The number of entities to which another entity can be associated via a relationship set is expressed as: a. Entity b. Cardinality c. Schema d. Attributes
7. Relations produced from an E-R model will always be in: a. First normal form b. Second normal form c. Third normal form d. Fourth normal form
8. In ER model the details of the entities are hidden from the user. This process is called: a. Generalization b. Specialization c. Abstraction d. none of these above
9. The file organization that provides very fast access to any arbitrary record of a file is: a. Ordered file b. Unordered file c. Hashed file d. B-tree
10. What is not true about a view? a. It is a definition of a restricted portion of the database b. It is a security mechanism c. It is always updatable like any other table d. All are true
11. In a relational database a referential integrity constraint can be specified with the help of a. primary key b. foreign key c. secondary key d. none of the above
12. A super key is a set of one or more attributes that, taken collectively, allow us a. to identify uniquely an entity in the entity set b. to make the key most powerful for faster retrieval c. to increase effectiveness of database access d. none of the above
13. 4NF is designed to cope with: a. Transitive dependency b. Join dependency c. Multi valued dependency d. None of these Prepared By Mr. Vipin Wani 1 Database Management System
14. Every Boyee-Codd normal form is in a. First normal form b. Second normal form c. Third normal form d. All of the above
15. Which command is used to remove all rows from a table? a. Delete b. Remove c. Truncate d. Both [A] and [B]
16. Which of the following is an aggregate function in SQL? a. Union b. Like c. Group By d. Max
17. Which command is used to add a column to an existing table? a. Create b. Update c. Alter d. None of these
18. A deadlock exists in the system if and only if the wait for graph: a. has a cycle in it b. has a path from first node to last node c. is a tree d. none of the above
19. Rollback of transactions is normally used to: a. recover from transaction failure b. update the transaction c. retrieve old records d. repeat a transaction
20. Prevention of access to the database by unauthorized users is referred to as: a. Integrity b. Productivity c. Security d. Reliability
21. In the relational modes, cardinality is termed as: (A) Number of tuples. (B) Number of attributes. (C) Number of tables. (D) Number of constraints.
22. Relational calculus is a (A) Procedural language. (B) Non- Procedural language. (C) Data definition language. (D) High level language.
23. The view of total database content is (A) Conceptual view. (B) Internal view. (C) External view. (D) Physical View.
24. Cartesian product in relational algebra is (A) a Unary operator. (B) a Binary operator. (C) a Ternary operator. (D) not defined.
25. DML is provided for (A) Description of logical structure of database. (B) Addition of new structures in the database system. (C) Manipulation & processing of database. (D) Definition of physical structure of database system.
26. ‘AS’ clause is used in SQL for (A) Selection operation. (B) Rename operation. (C) Join operation. (D) Projection operation.
27. ODBC stands for (A) Object Database Connectivity.(B) Oral Database Connectivity. (C) Oracle Database Connectivity. (D) Open Database Connectivity.
28. Architecture of the database can be viewed as (A) two levels. (B) four levels. (C) three levels. (D) one level.
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29. In a relational model, relations are termed as (A) Tuples. (B) Attributes (C) Tables. (D) Rows.
30. The database schema is written in (A) HLL (B) DML (C) DDL (D) DCL
31. In the architecture of a database system external level is the (A) physical level. (B) logical level. (C) conceptual level (D) view level.
32. An entity set that does not have sufficient attributes to form a primary key is a (A) strongentity set. (B) weak entity set (C) simple entity set (D) primary entity set
33. In a Hierarchical model records are organized as (A) Graph. (B) List. (C) Links. (D) Tree.
34. In an E-R diagram attributes are represented by (A) rectangle. (B) square. (C) ellipse. (D) triangle.
35. In case of entity integrity, the primary key may be (A) not Null (B) Null (C) both Null & not Null. (D) any value.
36. In tuple relational calculus P1 ®P2 is equivalent to (A) ¬P1 Ú P2 (B) P1 Ú P2 (C) P1 Ù P2 (D) P1 Ù¬P2
37. The language used in application programs to request data from the DBMS is referred to as the (A) DML (B) DDL (C) VDL (D) SDL
38. A logical schema (A) is the entire database. (B) is a standard way of organizing information into accessible parts. (C) describes how data is actually stored on disk. (D) both (A) and (C)
39. Related fields in a database are grouped to form a (A) data file. (B) data record. (C) menu. (D) bank.
40. The database environment has all of the following components except: (A) users (B) separate files. (C) database. (D) database administrator.
41. The language which has recently become the defector standard for interfacing application programs with relational database system is (A) Oracle. (B) SQL. (C) DBase. (D) 4GL.
42. The way a particular application views the data from the database that the application uses is a (A) module. (B) relational model.(C) schema. (D) sub schema.
43. In an E-R diagram an entity set is represent by a (A) rectangle. (B) ellipse. (C) diamond box. (D) circle.
44. A report generator is used to (A) update files. (B) print files on paper (C) data entry (D) delete files.
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45. The property / properties of a database is / are : (A) It is an integrated collection of logically related records. (B) It consolidates separate files into a common pool of data records. (C) Data stored in a database is independent of the application programs using it. (D) All of the above.
46. The DBMS language component which can be embedded in a program is (A) The data definition language (DDL). (B) The data manipulation language (DML). (C) The database administrator (DBA). (D) A query language.
47. DBMS is a collection of ………….. that enables user to create and maintain a database. A) Keys B) Translators C) Program D) Language Activity
48. In a relational schema, each tuple is divided into fields called A) Relations B) Domains C) Queries D) All of the above
49. In an ER model, ……………. is described in the database by storing its data. A) Entity B) Attribute C) Relationship D) Notation
50. DFD stands for A) Data Flow Document B) Data File Diagram C) Data Flow Diagram D) Non of the above
51. A top-to-bottom relationship among the items in a database is established by a A) Hierarchical schema B) Network schema C) Relational Schema D) All of the above
52. . ……………… table store information about database or about the system. A) SQL B) Nested C) System D) None of these
53. . …..defines the structure of a relation which consists of a fixed set of attribute-domain pairs. A) Instance B) Schema C) Program D) Super Key
54. . ……………… clause is an additional filter that is applied to the result. A) Select B) Group-by C) Having D) Order by
55. A logical schema A) is the entire database B) is a standard way of organizing information into accessible parts. C) Describes how data is actually stored on disk. D) All of the above
56. ………………… is a full form of SQL. A) Standard query language B) Sequential query language C) Structured query language D) Server side query language 57. A relational database developer refers to a record as A. a criteria B. a relation C. a tuple D. an attribute
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58. ………. keyword is used to find the number of values in a column. A. TOTAL B. COUNT C. ADD D. SUM
59. An advantage of the database management approach is A. data is dependent on programs B. data redundancy increases C. data is integrated and can be accessed by multiple programs D. none of the above
60. The collection of information stored in a database at a particular moment is called as …… A. schema B. instance of the database C. data domain D. independence
61. Data independence means A. data is defined separately and not included in programs. B. programs are not dependent on the physical attributes of data C. programs are not dependent on the logical attributes of data D. both B and C
62. A ……… is used to define overall design of the database A. schema B. application program C. data definition language D. code
63. Key to represent relationship between tables is called A. primary key B. secondary key C. foreign key D. none of the above
64. Grant and revoke are ……. statements. A. DDL B. TCL C. DCL D. DML
65. DBMS helps achieve A. Data independence B. Centralized control of data C. Neither A nor B D. Both A and B
66. ………. command can be used to modify a column in a table A. alter B. update C. set D. create
67. The candidate key is that you choose to identify each row uniquely is called …………….. A) Alternate Key B) Primary Key C) Foreign Key D) None of the above 68. …………….. is used to determine whether a table contains duplicate rows. A) Unique predicate B) Like Predicate C) Null predicate D) In predicate
69. To eliminate duplicate rows ……………… is used A) NODUPLICATE B) ELIMINATE C) DISTINCT D) None of these
70. State true or false i) A candidate key is a minimal super key. ii) A candidate key can also refer to a surrogate key. A) i-true, ii-false B) i-false, ii-true C) i-true, ii-true D) i-false, ii-false
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71. DCL stands for A) Data Control Language B) Data Console Language C) Data Console Level D) Data Control Level
72. …………………… is the process of organizing data into related tables. A) Normalization B) Generalization C) Specialization D) None of the above
73. A ………………. Does not have a distinguishing attribute if its own and most are dependent entities, which are part of some another entity. A) Weak entity B) Strong entity C) Non-attributes entity D) Dependent entity
74. …………….. is the complex search criteria in the where clause. A) Substring B) Drop Table C) Predict D) Predicate
75. ………………… is the preferred method for enforcing data integrity A) Constraints B) Stored Procedure C) Triggers D) Cursors
76. The number of tuples in a relation is called its …………. While the number of attributes in a relation is called it’s ……………….. A) Degree, Cardinality B) Cardinality, Degree C) Rows, Columns D) Columns, Rows
77. The language that requires a user to specify the data to be retrieved without specifying exactly how to get it is A. Procedural DML B. Non-Procedural DML C. Procedural DDL D. Non-Procedural DDL
78. Which two files are used during the 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
79. The database schema is written in A. HLL B. DML C. DDL D. DCL
80. The way a particular application views the data from the database that the application uses is a A. module B. relational model C. schema D. subschema
81. The relational model feature is that there A. is no need for primary key data B. is much more data independence than some other database models C. are explicit relationships among records. D. are tables with many dimensions
82. Which one of the following statements is false? A. The data dictionary is normally maintained by the database administrator Prepared By Mr. Vipin Wani 6 Database Management System
B. Data elements in the database can be modified by changing the data dictionary. C. The data dictionary contains the name and description of each data element. D. A data dictionary is a tool used exclusively by the database administrator.
83. Which of the following are the properties of entities? A. Groups B. Table C. Attributes D. Switchboards
84. Which database level is closest to the users? A. External B. Internal C. Physical D. Conceptual
85. Which are the two ways in which entities can participate in a relationship? A. Passive and active B. Total and partial C. Simple and Complex D. All of the above
86. …….. data type can store unstructured data A. RAW B. CHAR C. NUMERIC D. VARCHAR
87. …………… database is used as template for all databases created. A) Master B) Model C) Tempdb D) None of the above
88. One aspect that has to be dealt with by the integrity subsystem is to ensure that only valid values can be assigned to each data items. This is referred to as A) Data Security B) Domain access C) Data Control D) Domain Integrity
89. ………………….. operator is basically a join followed by a project on the attributes of first relation. A) Join B) Semi-Join C) Full Join D) Inner Join
90. Which of the following is not a binary operator in relational algebra? A) Join B) Semi-Join C) Assignment D) Project
91. Centralizing the integrity checking directly under the DBMS ………….. duplication and ensures the consistency and validity of the database. A) Increases B) Skips C) Does not reduce D) Reduces 92. Which of the following is/are the DDL statements? A) Create B) Drop C) Alter D) All of the above
93. In snapshot, …………………. clause tells oracle how long to wait between refreshes. A) Complete B) Force C) Next D) Refresh
94. ……………… defines rules regarding the values allowed in columns and is the standard mechanism for enforcing database integrity. A) Column B) Constraint C) Index D) Trigger
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95. For like predicate which of the following is true. i) % matches zero of more characters. ii) _ matches exactly one character. A) i-only B) ii-only C) Both of them D) None of them 96. State true or false. i) Select operator is not a unary operator. ii) Project operator chooses subset of attributes or columns of a relation. A) i-True, ii-False B) i-True, ii-True C) i-False, ii-True D) i-False, ii-False
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