## Lesson — Major LanceDB engine upgrades (e.g., v0.19 to v2.0.0)

**Tags:** lancedb, indexing, migrations

Major LanceDB engine upgrades (e.g., v0.19 to v2.0.0) can introduce changes to the underlying storage format that are not caught by API-level unit tests. A full index rebuild is required post-upgrade to prevent search panics and to enable performance improvements like enhanced FTS caching.
