Glossary

Open Table Format

An open table format is a published, engine-neutral metadata specification that makes a collection of files in object storage behave like a database table: tracking which files belong to the table, under what schema, across which versions. The three names are Apache Iceberg, Delta Lake, and Apache Hudi — with Iceberg having emerged as the industry’s neutral standard.

The mechanism is a small tree of metadata committed by atomic pointer swap, which yields ACID transactions, safe schema evolution, row-level updates and deletes, and time travel — on plain Parquet files. It is the ingredient that turns a data lake into a lakehouse, and “open” is the point: no single vendor owns your tables.

Go deeper: What Is an Open Table Format? Iceberg, Delta, and Hudi Explained