Open Data Infrastructure
Apache Polaris Interoperability Tests for ODI
Interoperability tests for Polaris-backed Iceberg catalogs across engines, namespaces, permissions, metadata, and exit paths.
A catalog is not interoperable because the slide says "REST." It is interoperable when multiple engines can prove the same table contract without special pleading.
The practical problem
Apache Polaris belongs in the ODI stack because it can anchor an open catalog boundary for Iceberg tables. But an open catalog can still become a closed control plane if only one engine, one permission model, or one deployment path works cleanly.
Interoperability has to be tested as behavior. The test suite should cover table discovery, namespace management, schema evolution, credential behavior, commit paths, audit signals, and migration out of the catalog. Otherwise the team has a catalog endpoint, not an open control plane.
Core idea: a Polaris interoperability test should prove that table control remains portable across engines, policies, and operating teams.
The tests that prove the boundary
The first test is engine diversity. Use at least two approved compute paths against the same Polaris-backed catalog and the same Iceberg table. One engine should create or alter the table, and another should read the result without private glue.
The second test is operation-level authorization. Read metadata, read data, create tables, alter schemas, commit snapshots, and manage namespaces should not collapse into one broad permission. The test should show which identity can do which operation and which denial appears in the audit trail.
The third test is metadata portability. Ownership, namespace conventions, table identifiers, and lineage references should be understandable outside one vendor experience. If the data is portable but the control context is not, the architecture still has an exit problem.
What breaks first
- One engine path works because it carries hidden configuration that the second engine does not have.
- Role names look clean, but permissions map poorly to actual Iceberg operations.
- Credential vending works for reads but not for writes, maintenance jobs, or streaming writers.
- Lineage captures the job after the fact but cannot explain which catalog policy allowed the operation.
Questions to ask
Use these questions before treating a Polaris deployment as ODI-ready.
- Can two engines create, evolve, read, and maintain the same table through the catalog?
- Can the test suite prove deny behavior as clearly as allow behavior?
- Can audit records connect identity, operation, table, engine, and policy?
- Can the catalog configuration move between environments without losing table identity?
- Can another REST-compatible catalog replace Polaris in a controlled exit test?
Pair this with What Is a REST Catalog?, Open Standard vs Open Source vs Open Governance, and Polaris vs Nessie vs Gravitino.
Sources to start with
Use the primary docs as the test contract. Then make the evidence executable.