You've have a point. But then, it's a bench mark and it would not be the first time that a bench is done using different settings than in production. Like I said, that lmdb is used in OpenLDAP doesn't automatically mean it is used with the exact same configuration as in the benchmark ;-) Nor did I say a memory store is bad, it's just you're not comparing the same things. Redis could be added to the bench for instance.