James, you assume a database but in reality it is not "setting an index" at all. In essence this is NOT a relational database. Therefore it is NOT that simplel.
Also the Wikidatification is a failure when it does not work for all languages equally well. That is not to say that the results will be the same; technically it should work equally well. That already is a big challenge.
Denormalisation again has everything to do with relational databases.. So in essence, you miss the point.