Apache Polaris Catalog

Apache Polaris Catalog

Apache Polaris is an open-source, Apache Software Foundation-governed implementation of the Apache Iceberg REST Catalog specification. It serves as the neutral, vendor-agnostic reference catalog for the Apache Iceberg ecosystem — providing a production-grade catalog server that any Iceberg-compatible engine can connect to without vendor lock-in.

Origins: Co-Created by Dremio and Snowflake

Apache Polaris was co-created by Dremio and Snowflake — two of the most prominent companies in the data lakehouse space — and jointly donated to the Apache Software Foundation. This cross-vendor collaboration was significant: it demonstrated that Dremio and Snowflake, despite being competitors in the data platform market, shared a strategic interest in establishing a neutral, open standard for Iceberg catalog infrastructure.

By placing Polaris under the Apache Foundation’s governance (rather than under either company’s control), both contributors ensured that Polaris would be a community asset — free for anyone to use, improve, and build upon.

Note: Dremio’s commercial Open Catalog capability is powered by Apache Polaris, deeply integrated into the Dremio platform as part of its Agentic Lakehouse architecture.

What Apache Polaris Implements

Polaris is a full implementation of the Iceberg REST Catalog specification — a standardized HTTP API for catalog operations. This means any engine or client that supports the Iceberg REST Catalog (Spark, Flink, Trino, Dremio, PyIceberg, DuckDB, and more) can connect to a Polaris server and immediately read and write Iceberg tables.

Core Capabilities

Namespace Management: Create and manage hierarchical namespaces (databases/schemas) within a catalog.

Table Lifecycle: Create, load, update (commit), and drop Iceberg tables with full atomic commit semantics.

View Support: Manage Iceberg views — stored SQL queries that appear as tables to downstream consumers.

Multi-Catalog Architecture: Polaris supports running multiple named catalogs in a single Polaris server instance, enabling multi-tenant deployments.

Credential Vending: Polaris issues short-lived, scoped object storage credentials to clients, so engines never hold long-lived cloud credentials. The client requests access, Polaris authenticates and authorizes, and returns temporary credentials scoped to the specific tables requested.

Fine-Grained Access Control: Role-based access control at the catalog, namespace, and table level. Polaris manages principals (users and service accounts) and their privileges.

Architecture Overview

Query Engine (Spark / Flink / Dremio / Trino / PyIceberg)
        │ Iceberg REST Catalog API (HTTP)
        ▼
Apache Polaris Server
  ├── Catalog management (namespaces, tables, views)
  ├── Authentication & authorization (OAuth2 / RBAC)
  ├── Credential vending (scoped object storage tokens)
  └── Metadata storage (internal persistence layer)
        │
        ▼
Object Storage (S3 / ADLS / GCS)
  └── Iceberg metadata files, manifest files, data files

The Iceberg REST Catalog Standard

Apache Polaris is the reference implementation of the Iceberg REST Catalog specification — a vendor-neutral HTTP API that standardizes how engines interact with catalogs. This standardization is transformative because:

1. Any engine can connect to any compliant catalog: Write once with the Iceberg REST Catalog API, connect to Polaris, Nessie, AWS Glue, or any other compliant implementation.
2. Eliminates catalog vendor lock-in: Switching from one catalog to another requires only configuration changes, not code changes.
3. Enables credential vending as a standard pattern: Security teams can enforce credential isolation without each engine implementing its own access control logic.

Polaris in the Dremio Ecosystem

Dremio describes itself as “The Agentic Lakehouse for AI and Analytics” and positions its Open Catalog capability — powered by Apache Polaris — as the interoperability backbone of the modern lakehouse. In Dremio Cloud and Dremio Enterprise:

• The Open Catalog exposes Iceberg tables to any Iceberg-compatible engine via the REST Catalog API.
• Dremio’s AI Semantic Layer, Intelligent Query Engine, and AI Agent capabilities all operate against the same catalog layer.
• Credential vending ensures that third-party engines (Spark, Flink, PyIceberg) access only the tables they are authorized to read — enforced at the catalog level, not just the query engine level.

Polaris vs. Other Catalogs

Getting Started with Apache Polaris

Apache Polaris is available as:

• Open-source code at github.com/apache/polaris
• Docker images for local development
• Managed service via Dremio Cloud (the Open Catalog)
• Managed service via Snowflake Open Catalog

For most teams, starting with Dremio Cloud’s free tier provides the fastest path to a production-grade Polaris-backed catalog without infrastructure management overhead.