Are these things about lookup documents still relevant for CB 5.0?
We think yes. We basically need to lookup a main-document by an additional field. We found that doing that lookup with N1QL is too much overhead and very slow. So we currently look into designing it using Lookup documents with the additional complications in the app-layer which needs to maintain these lookup documents.
Are there any new recommendations one year after this inital question? Maybe anything where you could leverage GSI for single document lookups by an additional GSI-indexed field without the whole N1QL overhead?