Indeed it's interesting to see aggregation as part of this list. Usually, the split of what can be pushed down to the storage layer and what cannot, is between

Indeed it's interesting to see aggregation as part of this list. Usually, the split of what can be pushed down to the storage layer and what cannot, is between stateless operations (filtering, projection) and stateful operations (e.g. joins, but also aggregations), as for instance they may require data from multiple storage nodes in a distributed data store.