The image above showing all five files is with PL3 Elite closed. Am running OSX 14.6 with latest build of PL3. If one were to want to back up the database, would you back up only the first one? Are the remaining four (on my machine) just temporary files that should go away on closing the program?
.shm and .wal files are created by the SQLite database engine and are all temporary and should be recreated if deleted.