Computer Database Objective Type Questions for All Competitive Exams

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Computer Database Objective Type Questions for All Competitive Exams || DBMS Questions

Q.1 In the relational modes, cardinality is termed as:

(A) Number of tuples. (B) Number of attributes.

(C) Number of tables. (D) Number of constraints.

Ans: A

Q.2 Relational calculus is a

(A) Procedural language. (B) Non- Procedural language.

(C) Data definition language. (D) High level language.

Ans: B

Q.3 The view of total database content is

(A) Conceptual view. (B) Internal view.

(C) External view. (D) Physical View.

Ans: A

Q.4 Cartesian product in relational algebra is

(A) a Unary operator. (B) a Binary operator.

(C) a Ternary operator. (D) not defined.

Ans: B Cartesian product in relational algebra is a binary operator. (It requires two operands. e.g., P X Q)

Q.5 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.

Ans: C DML is provided for manipulation & processing of database. (Data stored in the database is processed or manipulated using data manipulation language commands as its name)

Q.6 ‘AS’ clause is used in SQL for

(A) Selection operation. (B) Rename operation.

(C) Join operation. (D) Projection operation.

Ans: B ‘AS’ clause is used in SQL for rename operation. (e.g., SELECT ENO AS EMPLOYEE_NO FROM EMP)

Q.7 ODBC stands for

(A) Object Database Connectivity.

(B) Oral Database Connectivity.

(C) Oracle Database Connectivity.

(D) Open Database Connectivity.

Ans: D

Q.8 Architecture of the database can be viewed as

(A) two levels.

(B) four levels.

(C) three levels.

(D) one level.

Ans: C

Q.9 In a relational model, relations are termed as

(A) Tuples. (B) Attributes (C) Tables. (D) Rows.

Ans:c

Q.10 The database schema is written in

(A) HLL (B) DML (C) DDL (D) DCL

Ans: C

Q.11 In the architecture of a database system external level is the

(A) physical level. (B) logical level. (C) conceptual level (D) view level.

Ans: D

Q.12 An entity set that does not have sufficient attributes to form a primary key is a

(A) strong entity set. (B) weak entity set. (C) simple entity set. (D) primary entity set.

Ans: B

Q.13 In a Hierarchical model records are organized as

(A) Graph. (B) List. (C) Links. (D) Tree.

Ans: D

Q.14 In an E-R diagram attributes are represented by

(A) rectangle. (B) square. (C) ellipse. (D) triangle.

Ans: C

Q.15 In case of entity integrity, the primary key may be

(A) not Null (B) Null (C) both Null & not Null. (D) any value.

Ans: A

Q.16 Which of the following is correct:

(A) a SQL query automatically eliminates duplicates.

(B) SQL permits attribute names to be repeated in the same relation.

(C) a SQL query will not work if there are no indexes on the relations

(D) None of these

Ans: D

Q.17 In a relation

(A) Ordering of rows is immaterial

(B) No two rows are identical

(C) (A) and (B) both are true

(D) None of these.

Ans: C

Q.18 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)

Ans: A

Q.19 Related fields in a database are grouped to form a

(A) data file.

(B) data record.

(C) menu.

(D) bank.

Ans: B Related data fields in a database are grouped to form a data record. (A record is a collection of related fields)

Q.20 The database environment has all of the following components except:

(A) users.

(B) separate files.

(C) database.

(D) database administrator.

Ans: A

Q.21 The language which has recently become the defacto standard for interfacing application programs with relational database system is

(A) Oracle. (B) SQL. (C) DBase. (D) 4GL.

Ans: B

Q.22 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.

Ans: D

Q.23 In an E-R diagram an entity set is represent by a

(A) rectangle. (B) ellipse. (C) diamond box. (D) circle. Ans: A

Q.24 A report generator is used to

(A) update files.

(B) print files on paper.

(C) data entry.

(D) delete files.

Ans: B

Q.25 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.

Ans: D

Q.26 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.

Ans: B

Q.27 A relational database developer refers to a record as

(A) a criteria. (B) a relation.

(C) a tuple. (D) an attribute

Ans: C

Q.28 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.

Ans: B

Q.29 Conceptual design

(A) is a documentation technique.

(B) needs data volume and processing frequencies to determine the size of the database. (C) involves modelling independent of the DBMS.

(D) is designing the relational model.

Ans:C

Q.30 The method in which records are physically stored in a specified order according to a key field in each record is

(A) hash. (B) direct. (C) sequential. (D) all of the above.

Ans: A

A method in which records are physically stored in a specified order according to a key field in each record is hash. (In hash method, a hash function is performed on the key value to determine the unique physical address of the record to store or retrieve)

Q.31 A subschema expresses

(A) the logical view. (B) the physical view.

(C) the external view.

(D) all of the above.

Ans: C A subschema expresses the external view. (External schemas are called also called as subschemas)

Q.32 Count function in SQL returns the number of

(A) values. (B) distinct values. (C) groups. (D) columns.

Ans: A    Count function in SQL returns the number of values. (Count function counts all the not null values in the specific column. If we want to count only distinct values than the DISTINCT keyword is also to be used)

Q.33 Which one of the following statements is false?

(A) The data dictionary is normally maintained by the database administrator.

(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) The data dictionary is a tool used exclusively by the database administrator.

Ans: B

Q.34 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.

Ans: C

Q.35 A DBMS query language is designed to

(A) support end users who use English-like commands.

(B) support in the development of complex applications software.

(C) specify the structure of a database.

(D) all of the above.

Ans: D Q.

36 Transaction processing is associated with everything below except

(A) producing detail, summary, or exception reports.

(B) recording a business activity.

(C) confirming an action or triggering a response.

(D) maintaining data.

Ans: C

Q.37 It is possible to define a schema completely using

(A) VDL and DDL. (B) DDL and DML. (C) SDL and DDL. (D) VDL and DML.

Ans: B

Q.38 The method of access which uses key trAnsformation is known as

(A) direct. (B) hash. (C) random. (D) sequential.

Ans: B

Q.39 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).

Ans: D both (B) and (C)

Q.40 The statement in SQL which allows to change the definition of a table is

(A) Alter.

(B) Update.

(C) Create.

(D) select.

Ans: A

Q.41 E-R model uses this symbol to represent weak entity set ?

(A) Dotted rectangle.

(B) Diamond

(C) Doubly outlined rectangle

(D) None of these

Ans: C

Q.42 SET concept is used in :

(A) Network Model (B) Hierarchical Model

(C) Relational Model (D) None of these

Ans: A

Q.43 Relational Algebra is

(A) Data Definition Language.

(B) Meta Language

(C) Procedural query Language

(D) None of the above

Ans: C

Q.44 Key to represent relationship between tables is called

(A) Primary key

(B) Secondary Key

(C) Foreign Key

(D) None of these

Ans: C

Q.45 _______ produces the relation that has attributes of R1 and R2

(A) Cartesian product (B) Difference (C) Intersection D) Product

Ans: A

Q.46 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

Ans: C

Q.47 DBMS helps achieve

(A) Data independence

(B) Centralized control of data

(C) Neither (A) nor (B)

(D) both (A) and (B)

Ans: D

Q.48 Which of the following are the properties of entities?

(A) Groups (B) Table (C) Attributes (D) Switchboards

Ans: C

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