Hidden Partitioning: How Iceberg Eliminates Accidental Full Table Scans

This article is Part 5 of a 15-part Apache Iceberg Masterclass, focusing on hidden partitioning. It describes how Hive-style exposed partitioning leads to accidental full table scans when users filter on source columns instead of partition columns, causing 100x slower queries. Iceberg solves this by allowing users to filter on source columns like order_date, while the engine automatically applies transform functions (e.g., day()) to prune partitions. The article covers the six transform functions, how pruning works under the hood, choosing the right transform, and why this matters for teams. It is a technical deep dive into a key Iceberg feature for data lake performance.