Database Indexes Explained Simply: Why Some Queries Take 1ms and Others Take 10 Seconds (opens in new tab)

You've probably experienced this. Your app works perfectly during development. Then production arrives. A table grows from: 1,000 rows to: 10,000,000 rows Suddenly: pages load slowly APIs time out users complain CPUs start screaming The SQL query hasn't changed. So what happened? In many cases, the answer is surprisingly simple: You're missing an index. Index The Mystery of the Slow Query What Is a Database Index? A Real-Life Analogy How Databases Search Without an Index How Databases Search ...