Not sure if this is quite right... If you decided to add a "continuity" field that denoted which continuity a character was from, you'd probably want to use that data to relate characters -- in SQL land that would usually be a foreign key, in document stores, it's a little less clear how to do it (depending on which you pick) -- RethinkDB does (equi)joins, so you could just use a string. Can't say the same for other relational databases, I think the query would turn into a MapReduce.