How many IDs do we need?

[rowlesmr]

Is the goal to have an id data name for each Set category?

Do subcategories also need the id names of their parent? (eg _parent.id and _child.id & _child.parent_id? and if so, would all of the id data names form the key for that category?

[jamesrhester]

The part about all Set categories having a key data name (typically an identifier) is true. As for the second sentence, the only subcategories that objectively exist are those that are explicitly identified as children using _name.category_id, in which case all of the key data names must have equivalents.

For all other categories, they are simply tables floating in the ether, and the task is to work out which links to make between categories. So, for example, the atom_site category could have an atom_site.structure_id link to the structure category, which has a link to cell. Or instead it might have a link to cell called _atom_site.cell_id, and the cell category could link to structure via _cell.structure_id.