Aitem

-- jsonb_select_keys take jsonb and keys and return jsonb
-- contains only given keys
create or REPLACE function jsonb_select_keys (resource jsonb, keys text[] ) returns jsonb
as $$
select jsonb_object_agg(k, v)
from
  (select unnest(keys) k ) k ,
  lateral (select resource->k.k as v) t;
$$ LANGUAGE SQL
IMMUTABLE;