Why Database Partition Pruning Fails Without Careful Design

Episode 44 of Database Tech with Fexingo: Lucas and Luna dig into a subtle performance killer in partitioned databases — partition pruning that silently doesn't prune. They walk through how a real-world e-commerce system ran full-table scans on 200 partitions because the WHERE clause used a function-wrapped partition key. They explain how databases like PostgreSQL and MySQL handle partition elimination, why DATE() on a timestamp column defeats it, and the one index trick that can backfire. Listeners learn how to audit their own queries for accidental full scans, and why a seemingly clean schema can hide a 100x performance gap. This episode is for engineers who think their partitioned tables are fast — but haven't checked the query plan lately. #DatabasePartitioning #PartitionPruning #SQLPerformance #QueryOptimization #PostgreSQL #MySQL #DatabaseDesign #TechPodcast #DatabaseTechWithFexingo #DataEngineering #PerformanceTuning #Indexing #DatabaseInternals #FexingoBusiness #BusinessPodcast #Technology #SoftwareEngineering #BackendDev Keep every episode free: buymeacoffee.com/fexingo