When you create a database using the BDB SQL interface, a directory is created alongside of it. This directory has the same name as your database file, but with a -journal suffix.

That is, if you create a database called "mydb" then the BDB SQL interface also creates a directory alongside of the "mydb" file called "mydb-journal".

This directory contains files that are very important for the proper functioning of the BDB SQL interface. Do not delete this directory or any of its files unless you know what you are doing.

In Berkeley DB terms, the journal directory contains the environment files that are required to provide access to databases across multiple processes.