This database is mainly for recording "items". Here's my condition I create a project. In each projects are many episodes. In each episodes are many shots. In each shots are many items. Episode can only be under 1 project. Same as shots which will be under 1 episode and items which will only be under 1 shot. Users can choose filters to list the items. Like this Choose project --> load list of available episodes choose episode --> load list of available shots The user can choose only project alone to show all items under it, or choose episode too, or choose shot too. In this case, which table design would be more appropriate? Top or bottom?