Module persistence 

Persistence — save/load catalog and storage to/from disk.

Layout in database directory: catalog.json — serialized CatalogContent data/.bin — per-table row data in a simple binary format

Functions

load_catalog

Load catalog content from dir/catalog.json. Returns None if not found.

load_storage

Load all table data from dir/data/.

save_catalog

Save catalog content to dir/catalog.json.

save_storage

Save all table data to dir/data/<table_id>.bin.