Understanding Database Normalisation and Integrity

What is the primary goal of database normalisation?

• To increase data redundancy

• To reduce data redundancy and improve data integrity

• To make databases larger

• To decrease database performance

Which of the following is a requirement for a table to be in First Normal Form (1NF)?

• All non-key attributes must be fully functionally dependent on the primary key

• All entries in a column must be of the same data type

• There must be no transitive dependencies

• The table must have a composite key

What is the main difference between Second Normal Form (2NF) and Third Normal Form (3NF)?

• 2NF requires that all non-key attributes are fully functionally dependent on the primary key, while 3NF requires no transitive dependencies

• 2NF requires no transitive dependencies, while 3NF requires all non-key attributes to be fully functionally dependent on the primary key

• 2NF requires a composite key, while 3NF does not

• 2NF and 3NF are the same

Which of the following is NOT one of the ACID properties in relational databases?

• Atomicity

• Consistency

• Isolation

• Durability

• Scalability

What does referential integrity ensure in a relational database?

• That all data is encrypted

• That foreign keys correctly reference primary keys in another table

• That all tables are in Third Normal Form

• That all transactions are completed in real-time

Which SQL command is used to enforce referential integrity constraints?

• CREATE

• INSERT

• FOREIGN KEY

• SELECT

In the context of SQL, what does the term "relational database" refer to?

• A database that stores data in a hierarchical structure

• A database that stores data in tables with relationships between them

• A database that uses XML to store data

• A database that is used for storing multimedia files

Which of the following SQL statements is used to retrieve data from a database?

• UPDATE

• DELETE

• SELECT

• INSERT