Database Indexing Strategies: The Performance Lever You're Probably Misusing
Every junior developer learns that indexes make queries fast. What they don’t learn is that indexes also make writes slow, consume disk space, and can actively hurt performance when misused. Let’s fix that. What Indexes Actually Do An index is a separate data structure that maintains a sorted copy of specific columns, with pointers back to the full rows. Think of it like the index in a book — instead of reading every page to find “PostgreSQL,” you flip to the index, find the entry, and jump directly to page 247. ...