I've noticed that most of our API bottlenecks are due to slow database interactions. I want to start a 7-Day SQL Challenge focusing specifically on indexing and query execution plans. For those in software development, what are the most common SQL mistakes you see that tank performance, and how would you structure a week of learning to fix them?
3 answers
For a backend developer, the 7-Day SQL Challenge should be less about syntax and more about architecture. On the first two days, dive deep into B-Tree vs. Hash indexes. By mid-week, focus on identifying N+1 query problems which are notorious for slowing down REST APIs. I’ve seen so many developers forget to check if their ORM is generating efficient SQL. Use the last two days of your challenge to practice writing raw SQL that replaces heavy ORM logic for complex data fetching. This usually results in a significant boost in response times for your end-users.
Do you find that your team struggles more with the initial database design or with maintaining those indexes as the data grows over time?
Don't ignore the importance of understanding locks and transactions; they are usually the hidden culprits of API timeouts.
Totally agree with Brian. Deadlocks can be a nightmare to debug if you don't understand how your SQL isolation levels are actually working.
Good question, Joseph. It’s definitely the maintenance. We start with a clean design, but as we add features, the queries become bloated and we forget to update our indexing strategy. I’m hoping this week of focused study helps us build a more sustainable habit of checking query performance during every code review we perform.