clib mirror of the LMDB database from: https://symas.com/mdb/

LMDB is a tiny database with some great capabilities:

• Ordered-map interface (keys are always sorted, supports range lookups)
• Fully transactional, full ACID semantics with MVCC.
• Reader/writer transactions: readers don't block writers and writers don't block readers. Writers are fully serialized, so writes are always deadlock-free.
• Read transactions are extremely cheap, and can be performed using no mallocs or any other blocking calls.
• Supports multi-thread and multi-process concurrency, environments may be opened by multiple processes on the same host.
• Multiple sub-databases may be created with transactions covering all sub-databases.
• Memory-mapped, allowing for zero-copy lookup and iteration.
• Maintenance-free, no external process or background cleanup/compaction required.
• No application-level caching. LMDB fully exploits the operating system's buffer cache.
• 32KB of object code and 6KLOC of C.
• Licensed under the OpenLDAP Public License
• It is a read-optimized design and performs reads several times faster than other DB engines, several orders of magnitude faster in many cases. It is not a write-optimized design; for heavy random write workloads other DB designs may be more suitable.

The OpenLDAP Public License