Why do we have essentially duplicate pg_proc entries for json_extract_path
and json_extract_path_op? The latter is undocumented and seems only to be
used as the infrastructure for the #> operator. I see that only the
former is marked variadic, but AFAIK the operator machinery couldn't care
less about that, so it seems to me we could get rid of the
json_extract_path_op entry and point the operator at json_extract_path.
Likewise for json_extract_path_text_op, jsonb_extract_path_op, and
jsonb_extract_path_text_op.
regards, tom lane