Hacker News new | comments | show | ask | jobs | submit login hyc_symas 4 hours ago | link | parent You make some good points. We benchmark LMDB against LevelDB and its derivatives even though none of the LevelDB family offer ACID transactions. ( http://symas.com/mdb/ondisk/ ) Despite this fact, people will ask the question and try to make the comparison, so we run those tests. It's silly, but most people seem to pay attention to performance more than to safety/reliability. From my totally biased perspective, MDBM is utter garbage. They use mmap but make absolutely zero effort to use it safely . This was the biggest obstacle to overcome in developing LMDB; I had a few lengthy conversations with the SleepyCat guys about it as well. It's the reason it took 2 years (from 2009 when we first started talking about it, to 2011 first code release) to get LMDB implemented. If you want to call ...