What is metadata table querying in Iceberg?

Iceberg exposes a table's own internal metadata — snapshots, manifests, data files, history — as queryable "metadata tables," accessed by appending a suffix to the table name, letting an analyst or engineer inspect a table's structure and history using ordinary SQL rather than needing a separate tool to introspect Iceberg's internal files directly.

SELECT * FROM db.events.snapshots;
SELECT * FROM db.events.history;
SELECT * FROM db.events.files;
SELECT * FROM db.events.partitions;

The snapshots metadata table lists every snapshot with its ID, timestamp, and summary of changes; history shows the chronological sequence of snapshots that became the table's current state over time; files lists every current data file along with its size, record count, and column statistics; and partitions summarizes data volume and file counts per partition value.

These metadata tables are commonly used for operational visibility — auditing when a specific change happened by inspecting history, diagnosing a small-files problem by checking file counts in files or partitions, or identifying old snapshots that are safe to expire — all queryable through the same SQL interface used for the table's actual data, rather than requiring a separate, specialized metadata inspection tool.