Sorry, I don't know all the answers. However, I do know this (from the README):
> Core Engine (Storage & Search): Tantivy[1]
> Acts as both the primary storage for email content and the full-text search index. This unified approach ensures high performance and eliminates data redundancy.
> Core Engine (Storage & Search): Tantivy[1] > Acts as both the primary storage for email content and the full-text search index. This unified approach ensures high performance and eliminates data redundancy.
[1] https://github.com/quickwit-oss/tantivy