DATABASES GUIDE
MySQL Interview Questions for Developers
By the HireReadyAI team · 9 min read
Indexes, transactions, joins, locks, and how Node APIs should talk about MySQL.
Core topics
- Indexes and EXPLAIN
- Transactions and isolation levels
- Joins and when they explode
- Normalization vs practical denormalization
- Locks, deadlocks, and long transactions
Sample questions
Q: What does a covering index do? A: It contains all columns a query needs so MySQL can answer from the index without touching the table.
Q: Why do transactions matter for transfers? A: Atomicity — debit and credit succeed or fail together under concurrency controls.
From a Node API
Discuss pooled connections, statement timeouts, and avoiding N+1. Interviewers hiring Node engineers want database literacy, not DBA trivia alone.