I had no idea!

I always thought the catalogue was a duckdb file. E.g, data lives in partitioned parquet files, but which parquet files are current or soft deleted, etc, etc, is managed in a duckdb data file.

However, looking at https://ducklake.select/, it seems the catalogue lives in PostgresSQL - so it is not really a ducklake, but a postgresslake.

The more you know.