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Q.1 When a primary key is defined in the table DBMS automatically creates a ———-on a primary key column?
Unique Index
Sequence
Trigger
Synonym
Explanation
When a primary key is defined, the DBMS automatically creates a unique index on that column to ensure data integrity and to speed up data retrieval operations.
Q.2 Which normal form is the particular dependency removed?
First
second
Third
BCNF
Explanation
Second Normal Form (2NF) is specifically concerned with removing partial functional dependencies, ensuring that all non-key attributes are fully functional dependent on the primary key.
Q.3 Which is major data structure used in RDBMS?
Stacks
Graph
Array
none
Explanation
Relational databases conceptually organize data into tables, which are essentially two-dimensional arrays consisting of rows and columns.
Q.4 The view of total database content is:
Conceptual view
Internal view
External view
Physical view
Explanation
The conceptual view (or logical level) provides a complete description of the data stored in the database and the relationships between them for the entire community of users.
Q.5 Which is not aggregate function?
Count
Avg
Create
Max
Explanation
Aggregate functions perform a calculation on a set of values and return a single value. Count, Avg, and Max are aggregate functions, whereas ‘Create’ is a Data Definition Language (DDL) command.
Q.6 Under which category do the commands CREATE and ALTER belong to?
DML
DDL
Create
None of the above
Explanation
DDL stands for Data Definition Language. It includes commands like CREATE, ALTER, and DROP, which are used to define or modify the structure of database objects.
Q.7 ACID stands for?
Atomicity, Consistency, Isolation, Durability
Atomicity, Concurrency, Isolation, Durability
Aggregation, Consistency, Isolation, Durability
None of the above
Explanation
ACID is an acronym for Atomicity, Consistency, Isolation, and Durability. These are a set of properties that guarantee that database transactions are processed reliably.
Q.8 How many primary key can a table in database?
Only one
At least one
More than one
Any number of
Explanation
A database table can have only one primary key. However, this primary key can consist of a single column or multiple columns (which is then called a composite key).
Q.9 Which of the following are the properties of entities?
Groups
Table
Attributes
None of the above
Explanation
In database modeling, attributes are the characteristics or properties that describe an entity (for example, ‘Name’ and ‘Age’ are attributes of a ‘Student’ entity).
Q.10 Relational algebra is?
DDL
Meta Language
Procedural Query Language
None of the above
Explanation
Relational algebra is a procedural query language because it describes the steps or operations (like select, project, join) required to get the desired result from the database.
Q.11 The statement in SQL which allows to change definition of table is?
Alter
Update
Create
Select
Explanation
The ALTER statement is used to add, delete, or modify columns in an existing table, effectively changing the table’s definition/structure.
Q.12 Count function in SQL returns the number of?
Values
District Values
Groups
Columns
Explanation
The COUNT() function returns the number of rows that match a specified criterion or simply the number of non-null values in a specific column.
Q.13 In an E-R diagram Entity set is represented by?
Ellipse
Square
Rectangle
None of the above
Explanation
In Entity-Relationship (ER) diagrams, rectangles are used to represent entity sets, while ellipses represent attributes and diamonds represent relationships.
Q.14 The language used in application program to request data from DBMS is referred as:
DML
DDL
VOL
SOL
Explanation
DML (Data Manipulation Language) is the component of SQL used for accessing and manipulating data, such as retrieving (SELECT), inserting, or updating records.
Q.15 The number of attributes in a relation is called its———
Row
Column
Degree
None of the above
Explanation
The degree of a relation is the total number of attributes (columns) it contains. The total number of tuples (rows) is called its cardinality.
Q.16 Which of the following is not a type of Database?
Hierarchical
Relational
Network
Transition
Explanation
Hierarchical, Relational, and Network are established database models. ‘Transition’ is not a recognized category of database architecture.
Q.17 SELECT * from employee is what type of statement?
DML
DDL
View
Integrity Constraint
Explanation
The SELECT statement is classified as DML (Data Manipulation Language) because it is used to retrieve and view data from the tables.
Q.18 The full form of DDL is:
Dynamic Data Language
Detailed Data Language
Data Definition Language
None of the above
Explanation
DDL stands for Data Definition Language, which is used to define the database schema and structure.
Q.19 Which database is closest to the users?
External
Internal
Physical
Conceptual
Explanation
In the three-level architecture of a DBMS, the external level (or view level) is the one closest to the users as it describes only the part of the database relevant to a specific user.
Q.20 Which of the following is comparison operator in SQL?
=
LIKE
BETWEEN
All of the above
Explanation
SQL provides several comparison operators to filter data, including the equals sign (=), the LIKE operator for pattern matching, and the BETWEEN operator for range filtering.