Partition Statistics Files in Apache Iceberg
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.
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652 posts on Apache Iceberg, lakehouse architecture, data engineering and applied AI.
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.
Credential vending end to end: the wire protocol, scoped access on each cloud, remote signing, credential lifetime on long jobs, and failures that look like bugs.
Exactly-once semantics in the Iceberg sink connector: the coordinator, the control topic, offsets stored inside Iceberg snapshots, and where duplicates still get in.
Four meters, their real proportions, and how to attribute compute to a query, a table, and a team so a platform can answer what a dashboard costs to run.
The five layers of the open lakehouse explained, then a lab: Parquet, Iceberg, Polaris, Arrow, and Ossie running in two containers on your own machine.
The format war ended and exit cost did not: where lock-in relocated after open tables won, how to measure it, and which costs are worth keeping down.
A comparison of Great Expectations, Soda, dbt tests, and anomaly detection, and a layered design that uses each where it fits.