Select Edit-->preferences to set configuration options for mdb. The window that appears has four tabs for setting view, players, backup and SQL preferences. The first controls which fields are displayed and which must be present to include a track in the data base. The players tab controls which audio players are used for which file formats. It allows new players to be added to mdb. The backup specifies how frequently edited playlists are backed up. This is not a substitute for manually saving playlist to backup your work. Its main purpose is to provide a backup if the main data base becomes corrupted.
The last is an experimental feature to build a PostgreSQL database of the information in the library.
In addition to these preferences you can control window sizes and field widths.
Creating a PostgreSQL database
Window and field sizes