DBMS-30-7-25

Which of the following best describes a relational database?

• A database that stores data in a single file.
• A database that stores data in tables with relationships between them.
• A database that uses only key-value pairs.
• A database that organizes data in a hierarchical structure.

What is the main objective of a relational database system?

• To store and manage data in a structured way that maintains relationships and integrity.
• To provide a graphical user interface for applications.
• To ensure data is only stored in text format.
• To create and delete files on a server.

Which of the following is a popular relational database management tool?

• PostgreSQL
• MongoDB
• SQLite
• MySQL

What is data redundancy in databases?

• Data redundancy is the unnecessary duplication of data in a database.
• Data redundancy is the organization of data into multiple databases for efficiency.
• Data redundancy refers to the elimination of duplicate data in a database.
• Data redundancy is the process of compressing data in a database.

What is a common effect of redundancy in databases?

• Data inconsistency/update anomaly

• Increased data retrieval speed
• Enhanced data security
• Improved data organization

If A → B in a relation, then B is functionally dependent on A. This means:

• A and B are unrelated entities.
• B is functionally dependent on A.
• B is independent of A.
• A is functionally dependent on B.

Which symbol represents functional dependency?

• <=>
• ==>
• ~>
• ->

What is the purpose of normalization in relational databases?

• To reduce data redundancy and improve data integrity in relational databases.

• To enhance the visual representation of data in reports.
• To simplify database queries by merging tables.
• To increase data duplication for faster access.

A relation is in First Normal Form (1NF) if

• It requires all attributes to be unique.
• It contains nested tables within the relation.
• It allows duplicate values in a column.
• It contains only atomic values and no repeating groups.

A table is in Second Normal Form (2NF) if:

• A table is in 2NF if it has no transitive dependencies.
• A table is in 2NF if it is in 1NF and has no partial dependencies.
• A table is in 2NF if it contains only unique values.
• A table is in 2NF if it has a primary key defined.