Most teams think Apache Iceberg migration pain comes from data layout. It doesn't. It comes from the catalog. Moving metadata takes one API call. Rebuilding your roles, grants, and credential delegation takes months. We compared Nessie vs Polaris vs Unity vs Glue vs HMS:
🧵 Key takeaways: • "Supports REST" standardizes wire protocol, NOT permissions or credential behavior. • Registering one table in two writable catalogs is a direct recipe for data corruption. • Nessie wins on branching, but pins older Iceberg versions.
• Snowflake can write to Unity-managed tables (GA on Azure), but Unity keeps write authority. • The boring choice (Glue/HMS + REST front-door) often beats catalogs you can't run at 3 AM.
Full guide + interactive catalog picker & write-path test protocol: 🔗 t.co/czJzUDqJ4O #ApacheIceberg #DataEngineering
