This is to have multiple relations returned. Traditional unions and joins only see one relation returned. You can pack multiple relations into one relation usi

This is to have multiple relations returned. Traditional unions and joins only see one relation returned. You can pack multiple relations into one relation using unions/joins and then unpack it again in the client to ultimately achieve the same effect, which is a workaround that some utilize, but that is really hacky (to be clear, unions and joins are not hacks when used for their intended purpose, but the data packing is). The proposed would be much less hacky - although still far from an ideal database that has no latency constraints that force deviation from what is "pure". But that’s engineering for you.