To temper my rant (whose edit window has expired), I just want to note that Berkeley DB clearly was, at one point, a very well-designed, minimalistic and modular embedded key-value store. Almost all of my issues are with the features it has grown, like barnacles, over the past decade (or even two) to accommodate use cases which are better served by other databases designed with those features in mind. If you use it for what it was originally designed for, I am sure it is fantastic. Just don't pretend that it's anything more, despite what its most recent incarnations claim it to be.