Local Schema Migrations

A local schema migration changes stored data so a newer app can use it. The input may include years of records, skipped releases, unsynced edits, and uncertain operations.

The migration succeeds only if the new app can use the data and important user work remains recoverable.

Version the stored format separately

An app version and a schema version are different. Several app releases may use one schema. A schema change may affect tables, indexes, pending-operation payloads, and file references together.

Provide a tested path from every supported starting schema