Litestream VFS

Litestream VFS is a SQLite plugin that enables querying databases directly from object storage backups without downloading the entire database. It supports point-in-time recovery through SQL pragmas, allowing instant queries against historical database states. The system uses LTX file format for efficient page-level compaction, fetches only needed pages via S3 range requests, implements LRU caching for hot pages, and can maintain near-realtime replicas by polling backup storage every second. The VFS module works as a plugin to existing SQLite installations without requiring application modifications.