LMDB is kinda unique in KV segment. It's fast, gives access to zerocopy values, full ACID. I use it for inverted index where SQLite quite sucks. The only issue

LMDB is kinda unique in KV segment. It's fast, gives access to zerocopy values, full ACID. I use it for inverted index where SQLite quite sucks. The only issue with LMDB is a size reservation for a db file.