Mastering RDBMS Concepts

What is the primary purpose of database normalization?

• To increase data duplication and decrease data integrity.

• To enhance user interface design and improve accessibility.

• To simplify database queries and reduce performance.

• To reduce data redundancy and improve data integrity.

Explain the difference between 1NF and 2NF.

• 1NF focuses on atomicity of data, while 2NF addresses partial dependencies on the primary key.

• 1NF allows duplicate rows, while 2NF does not.

• 1NF requires a primary key, while 2NF does not.

• 1NF is about data types, while 2NF is about data relationships.

What is a functional dependency in the context of normalization?

• A process of deleting duplicate records.

• A method for organizing data into tables.

• A relationship where one attribute's value determines another attribute's value.

• A technique for encrypting sensitive information.

How does normalization help in reducing data redundancy?

• Normalization reduces data redundancy by organizing data into related tables, ensuring each piece of data is stored only once.

• Normalization increases data redundancy by duplicating data across tables.

• Normalization eliminates the need for related tables in a database.

• Normalization allows for storing multiple copies of the same data in one table.

What are the different normal forms in database design?

• 1NF, 2NF, 3NF, 4NF, 7NF

• 1NF, 2NF, 3NF, 6NF

• 1NF, 2NF, 3NF, 4NF, 5NF, 6NF

• 1NF, 2NF, 3NF, BCNF, 4NF, 5NF

What is SQL query optimization and why is it important?

• SQL query optimization is the process of improving the performance of SQL queries, which is important for enhancing application speed, reducing resource usage, and improving user experience.

• SQL query optimization is the process of creating new databases.

• SQL query optimization is only necessary for large datasets.

• SQL query optimization is about writing SQL queries in different programming languages.

List three common techniques for optimizing SQL queries.

• Use stored procedures

• Increase server memory

• 1. Use indexing 2. Rewrite queries for efficiency 3. Analyze execution plans

• Limit database connections

What role do indexes play in SQL query performance?

• Indexes are primarily used for data storage rather than retrieval.

• Indexes significantly enhance query performance by speeding up data retrieval.

• Indexes are only useful for large databases and have no effect on small ones.

• Indexes slow down data retrieval by adding overhead.

How can the use of joins affect query performance?

• Joins always improve query performance by simplifying data retrieval.

• Joins can slow down query performance due to increased data processing and complexity.

• Joins have no impact on query performance regardless of data size.

• Joins can only enhance performance when used with indexed tables.

What is the purpose of data integrity constraints in a database?

• To enhance the speed of data retrieval.

• The purpose of data integrity constraints in a database is to maintain the accuracy and consistency of data.

• To reduce the size of the database.

• To allow unlimited data entry without checks.