Apache Iceberg has become a popular choice for managing large datasets with flexibility and scalability. Catalogs are central to Iceberg’s functionality, which is vital in table organization, consistency, and metadata management. This article will explore what Iceberg catalogs are, their various implementations, use cases, and configurations, providing an understanding of the best-fit catalog solutions for different use cases.

What Is an Iceberg Catalog?

In Iceberg, a catalog is responsible for managing table paths, pointing to the current metadata files that represent a table’s state. This architecture is essential because it enables atomicity, consistency, and efficient querying by ensuring that all readers and writers access the same state of the table. Different catalog implementations store this metadata in various ways, from file systems to specialized metastore services.