This will make complex upserts so much more simple, fantastic addition. I really hope `RETURNING` support gets added to `MERGE` asap though (I believe it's bee

This will make complex upserts so much more simple, fantastic addition. I really hope `RETURNING` support gets added to `MERGE` asap though (I believe it's been noted as a fairly trivial addition to come in future), then it'll be super powerful for doing bulk upserts that require post-processing.