Databases
Explore core database concepts and real-world usage, from relational modeling to SQL querying and performance basics. These quizzes help you review terminology, choose the right data structures, and understand how databases store, retrieve, and protect data.
Quizzes
Transactions and isolation levels explained
Test your understanding of database transactions and isolation levels with practical, scenario-based questions. You’ll review ACID, locking, MVCC, and classic anomalies like dirty reads and phantom reads. Mix fundamentals with real-world troubleshooting to strengthen your SQL and system design instincts.
Indexing basics: B-trees and hash
Build a solid foundation in database indexing with B-tree and hash indexes. You’ll test how indexes speed up reads, what trade-offs they introduce on writes, and which index type fits common query patterns. Choose your preferred difficulty and number of questions, then learn from every explanation—no timer pressure.
SQL joins: inner, left, and full
Test your understanding of SQL joins with a focused set of questions on INNER, LEFT, and FULL joins. You’ll practice reading result sets, predicting row counts, and spotting when NULLs appear. Great for interview prep or sharpening everyday query skills.
What you'll find here
- Curated quizzes focused on Databases
- Difficulty spread from easy to hard
- Randomized questions with instant feedback
- Quizzes you can replay and compare on the leaderboard
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Category FAQ
How many quizzes are available?
There are 3 quizzes with 348 questions total.
Do these database quizzes require SQL experience?
Basic SQL helps, but many questions cover concepts like keys, normalization, and transactions that you can learn as you go.
How are the questions formatted?
Each question has 4 options and there is no timer, so you can answer at your own pace.
Are the quizzes suitable for interview prep?
Yes. They cover common interview topics like joins, indexes, normalization, and ACID properties in a quick practice format.
What difficulty level should I start with?
Start with the shorter or more basic quiz to gauge your level, then move to longer sets that include performance and transaction scenarios.
More to explore
What you’ll practice
These Databases quizzes focus on practical knowledge you’ll use in analytics, backend development, and data engineering—especially how data is modeled, queried, and kept consistent.
You’ll review essentials like tables and relationships, keys and constraints, normalization, joins, transactions, and indexing, plus common database terms you’ll see in documentation and interviews.
How the quizzes work
Each question has 4 answer options and there’s no timer, so you can think through query logic and definitions without rushing.
Difficulty and length vary across the set: some quizzes are quick refreshers while others go deeper into advanced scenarios, so you can pick an easier run-through or a longer, more challenging session.
Helpful database facts
Many modern systems still rely on foundational relational ideas introduced decades ago, and concepts like ACID transactions and indexing remain central even as NoSQL and distributed databases have grown.
Understanding why an index speeds up reads (but can slow writes) or how isolation levels affect concurrency can make a noticeable difference in real application performance.
Tips for better results
- Read the full question first, then eliminate clearly wrong options
- Watch for details about NULL handling, constraints, and join types
- Think about trade-offs: consistency vs performance, reads vs writes
- Review why an answer is correct, not just which option it is
- Re-take missed questions to reinforce key definitions and patterns