Standard

Iceberg REST Catalog Spec

An open REST API specification for Apache Iceberg catalog operations, enabling multi-engine interoperability through a standardized HTTP-based catalog interface.

9 connections 3 resources

Summary

What it is

An open REST API specification for Apache Iceberg catalog operations, enabling multi-engine interoperability through a standardized HTTP-based catalog interface.

Where it fits

The REST Catalog Spec solves the catalog fragmentation problem in the Iceberg ecosystem. Instead of every engine needing native support for Hive Metastore, Glue, Nessie, etc., any catalog that implements the REST spec becomes accessible to all REST-capable engines.

Misconceptions / Traps
  • The REST Catalog Spec defines the API contract, not the catalog implementation. Performance, consistency, and feature completeness depend on the catalog server behind the API.
  • Not all Iceberg catalog operations may be supported by every REST catalog implementation. Check compatibility for advanced features like branching, tagging, and view support.
Key Connections
  • scoped_to Iceberg Table Spec, Table Formats — standardizes catalog access for Iceberg
  • solves Vendor Lock-In — engine-agnostic catalog access
  • solves Metadata Overhead at Scale — enables centralized catalog management

Definition

What it is

An open specification defining a RESTful HTTP API for Iceberg catalog operations — listing namespaces and tables, loading table metadata, committing updates, and managing snapshots — independent of any specific catalog backend.

Why it exists

Iceberg catalogs were historically tied to specific implementations (Hive Metastore, AWS Glue, Nessie). The REST Catalog Spec decouples catalog clients from catalog backends, enabling multi-engine, multi-language interoperability through a universal HTTP interface.

Primary use cases

Multi-engine Iceberg catalog access, vendor-neutral catalog interoperability, cloud-managed Iceberg catalogs, cross-language catalog clients.

Connections 9

Outbound 4
scoped_to2
Table FormatsLakehouse
enables1
Lakehouse Architecture
solves1
Vendor Lock-In
Inbound 5
implements5
Apache PolarisApache GravitinoUnity CatalogAWS Glue CatalogProject Nessie

Resources 3

SpecHigh
github.com/apache/iceberg/blob/main/open-api/rest-catalog-op...

OpenAPI specification for the Iceberg REST Catalog, the standard API for multi-engine catalog interoperability.

DocsHigh
iceberg.apache.org/concepts/catalog/

Iceberg catalog concepts documentation explaining catalog types, REST catalog design, and configuration.

BlogMedium
tabular.io/blog/rest-catalog-intro/

Introduction to the Iceberg REST Catalog from Tabular (founded by Iceberg creators) explaining design motivations and architecture.