If you have a lot of graphics files, you may want to organize them into separate databases. This option allows you to select another database to open.
ThumbsPlus databases have the extension .tpdb8. Each of these databases has an associated option (INI) file, with the extension .tdo.
ThumbsPlus can only open a single database at a time, though you can run ThumbsPlus multiple times, each time with a different (or the same) database.
You can specify the database for ThumbsPlus to use on the command line, from Explorer. You can also double-click on .tpdb8 files Windows Explorer to bring up ThumbsPlus with a specific database.
To create a new database, use the File | Database | New Database.