LMDB Embedded Database

LMDB (Lightning Memory-Mapped Database) is a tiny, ultra-fast embedded key-value store. It uses memory-mapped I/O (OS handles paging files in/out of memory), supports ACID transactions, and requires no external server. Written in C, <100KB binary, zero dependencies. LMDB is ideal for applications needing fast local storage—caching, session storage, time-series data, embedded systems, blockchain nodes. Not suitable for complex queries (no SQL); designed for simple key-value access.