The underused Iceberg metadata for planning: what the partition statistics file holds, what the spec guarantees, how to write one, and when it earns its slot.
Fixtures, in-memory catalogs, and golden metadata: the assertions that catch wrong rows, unsafe reruns, schema drift, and concurrent-write corruption in CI.
A repeatable test for what an Iceberg REST catalog actually serves, a scoring scheme that separates design from breakage, and the 2026 evidence across seven catalogs.
Three multi-region topologies that work and one that mostly does not, what an Iceberg commit costs across regions, and where the catalog has to live.
