Tobias Oberstein wrote:

Hello,

I have read the - very interesting - performance comparison
http://symas.com/mdb/microbench/

I'd like to ask if someone did benchmark LMDB (and/or the others)
against http://www.garret.ru/fastdb.html

FastDB is an in-memory ACID database that works via shadow paging, and
without a transaction log.

OK, like LMDB it uses shadow root pages. I think the similarity ends there.
It is a relational database with an ASCII query language, while LMDB is strictly a key/value store. That automatically means for simple get/put operations LMDB will be orders of magnitude faster (just as it is so much faster than SQLite3 and SQLite4).