I'm currently designing a database for concerts, so I have created the following entity-relationship diagram (ERD):
Business domain characteristics
A concert can take place on a regular event or a festival. A festival "uses" all the attributes an event has, but it also holds some additional ones. The same goes with festival_concerts and concerts.
As festival_concerts and concerts are processed the same way in some places but completely different in other places, they need to be separated.
Because of that, I planned to store the additional attributes in a second table that uses the concert primary key as primary key too. The other way was to store them in completely seperate tables. If using my plan, I'd like to clean up the ERD so this weird rectangle-relationship doesn't exist anymore. Which way do you recommend?