The Metadata Structure of Modern Table Formats

This is Part 2 of a 15-part Apache Iceberg Masterclass . Part 1 covered why table formats exist. This article breaks down exactly how each format organizes its metadata. The metadata structure of a table format determines everything: how fast queries start planning, how efficiently concurrent writes are handled, how schema changes propagate, and how much overhead accumulates over time. Two formats can both claim "ACID support" and "time travel" while having fundamentally different mechanisms und