Table File may not necessary to be include in database. Does table File mean the original file which the user uploads? Do we need to save the original file in our database?
Could add a User table. Although we don't have login function, I think we still need to storage user's email to send the transcription and status report after transcribe. And user data may affect the authentication process for accessing history portal.
According to class diagram, should we build a new table for history record, which includes non-expired files and expire dates for each non-expired files?
I'm not sure if we need to create a table for files in the queue of transcribing. Do you think it can make sense? For the function of queue, we need to know the quantities of files in the transcribing process and estimated waiting time for the first files waiting to transcribe for the user. But I don't know if it is necessary to be storaged in database.