You're right, I don't remember the terminology well. And yes, I remember edges having these properties as well. This made me think that graphs are essentially

You're right, I don't remember the terminology well. And yes, I remember edges having these properties as well. This made me think that graphs are essentially more complex. With a simple relational DB what you have essentially is a table/mapping/dictionary-like structure. (Even when storage is columnar, the API is still behaving like a table/map/dict.) With a graph, if we only keep the info about edges, it also becomes a key=>value map, where key is node A & B list/set, and values are edge properties. But as soon as we try storing info about nodes, this requires a second table. Wikidata has to make yet another table, with types of edges and nodes.