Apache Polaris is an open-source catalog service for Apache Iceberg. Originally developed by Snowflake and open-sourced in June 2024, it was donated to the Apache Software Foundation (ASF) and officially graduated to a Top-Level Project in early 2026. Polaris serves as a centralized metadata management layer that allows multiple, disparate compute engines to interact securely and seamlessly with Iceberg tables.
By implementing the open Iceberg REST Catalog API, Polaris ensures that organizations can decouple their storage and catalog layers from specific compute vendors, achieving true architectural flexibility and preventing vendor lock-in.
Core Capabilities
- Engine Interoperability: Any query engine that supports the Iceberg REST standard (which includes Apache Spark, Apache Flink, Dremio, Trino, and Snowflake) can connect to a Polaris catalog out-of-the-box. No custom connectors or proprietary translation layers are required.
- Unified Governance and RBAC: Polaris acts as the central gatekeeper for data access. It provides a unified Role-Based Access Control (RBAC) model, allowing administrators to define fine-grained security policies in one place. These policies are enforced uniformly, regardless of which compute engine requests the data.
- Credential Vending: To enhance security, Polaris integrates with cloud IAM (Identity and Access Management) systems to vend short-lived, scoped credentials to compute engines. The engine receives temporary access to read or write specific object storage paths (S3, ADLS, GCS) only after Polaris verifies the user's authorization, eliminating the need to distribute long-lived storage keys to various client applications.
- Flexible Deployment: As an open-source project with mature Kubernetes support (Helm charts), Polaris can be self-hosted on-premises, deployed in public or private clouds, or consumed as a managed service from various vendors, providing deployment flexibility to match security and operational requirements.
The Shift Toward Vendor Neutrality
Before Polaris, organizations looking to adopt Iceberg often had to rely on proprietary or cloud-specific catalogs like AWS Glue, or adapt the legacy Hive Metastore. Polaris fills the critical need for a modern, security-focused, and robust catalog that is entirely open-source and governed by the ASF. It cements the Iceberg ecosystem's commitment to openness, ensuring that the catalog layer - the crucial component that defines the table's state - remains under the organization's control.
