SQL Antipatterns

Objective: Optimize Performance

Performance is the single most common concern I hear from database developers. Just look at the talks scheduled at any technical conference: they’re full of tools and techniques to squeeze more work out of your database. When I give a talk about a way to structure a database or write SQL to give better reliability, security, or correctness, I’m not surprised when the only question from the audience is, “OK, but how does that affect performance?”

The best technique for improving performance in your database is to use indexes well. An index is a data structure that the database uses to correlate values to the rows where these values occur in a given column. An index provides an easy way for the database to find ...