Why Your Database Indexes Are Slowing Your Queries

On this episode of The Web Development Podcast, Lucas and Luna dig into a counterintuitive database performance trap: the index that looks helpful on paper but quietly degrades your write throughput and even some reads. Lucas walks through a real-world case from a mid-size e-commerce platform where adding a composite index on order status and created_at made the nightly batch job run 40 percent slower. They explain how B-tree depth, index selectivity, and write amplification interact, and why a multi-column index that seems perfect for a query can actually force the database to scan more pages than a full table scan. Luna shares a story about a PostgreSQL query planner choosing a bitmap scan over a perfectly good single-column index because the statistics were stale — and what the team did to fix it. They also cover practical tips for monitoring index bloat, using pg_stat_user_indexes, and knowing when to drop an index entirely. If you've ever added an index and seen no improvement, or worse, a regression, this episode is for you. #DatabasePerformance #PostgreSQL #Indexing #QueryOptimization #WebDev #Technology #FexingoBusiness #BusinessPodcast #Backend #SQL #BTree #WriteAmplification #IndexBloat #pgStatUserIndexes #CompositeIndex #BitmapScan #EcommerceBackend #DatabaseTuning Keep every episode free: buymeacoffee.com/fexingo