Showing posts with label Conceptual view. Show all posts
Showing posts with label Conceptual view. Show all posts

Wednesday, September 23, 2020

Database Systems MCQ

 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., PXQ)


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:


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 In tuple relational calculus P1 -> P2 is equivalent to

(A) ¬P1vP2 

(B) P1vP2

(C) P1^P2 

(D) P1^¬P2

Ans: A In tuple relational calculus P1 -> P2 is equivalent to ¬P1vP2. (The logical implication expression A->B, meaning if A then B,is equivalent to ¬AvB)


Q.17 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

Ans: A


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

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