DSpace: Determine size (in bytes) of a community (top of 3 tiers)

gistfile1.sql

SELECT SUM(size_bytes) 
  FROM bitstream, bundle, bundle2bitstream, item2bundle 
  WHERE item2bundle.bundle_id = bundle2bitstream.bundle_id 
    AND bundle2bitstream.bitstream_id = bitstream.bitstream_id 
    AND item2bundle.bundle_id = bundle.bundle_id 
    AND bundle.name = 'ORIGINAL' 
    AND item2bundle.item_id = ANY(
      SELECT item_id 
      FROM item 
      WHERE owning_collection = ANY(
      SELECT collection_id 
      FROM community2collection 
      WHERE community_id = ANY(
        SELECT child_comm_id 
        FROM community2community 
        WHERE parent_comm_id = 19)
  )
);