[matt123456789]

It is not a chicken and egg problem, it is just a requirement to have an RDBMS available for systems like DuckLake and Hive to store their catalogs in. Metadata is relatively small and needs to provide ACID r/w => great RDBMS use case.

[dsp_person]

What about file-based catalogs with Iceberg? Found one that puts it in a single json file: https://github.com/boringdata/boring-catalog

[saxenaabhi]

Then concurrency suffers since you have to have locks when you update files.

That's also why ducklake performs better than others.

For many use cases this trade-off is worth it.