If you are a SQLite user who is migrating to the BDB SQL interface, then there are a few Berkeley DB-specific concepts you might want to know about.
Environments. The directory that is created alongside your database file, and which ends with the "-journal" suffix, is actually a Berkeley DB environment directory. This might be interesting to you in some administrative situations. For some minimal information on what an environment is, see Introduction to Environments.
The Locking Subsystem
You can configure the maximum number of locks that can be in use at any given time when you use the BDB SQL interface. This is probably only interesting to you if you are using the BDB SQL interface in a concurrent application that is running a very large number of transactions.
For information on configuring your locking subsystem, see Managing the Locking Subsystem.
The Logging Subsystem
The BDB SQL interface maintains log files in its journal directory, and you can manage various aspects of these. For the overwhelming majority of applications, there is no need to manage this. But for the sake of completeness, this topic is described in this manual.
For more information, see Administering Log Files.