`select a->'$.a'` equals to `select json_extract(a, '$.a')`; `select a->>'$.a'` equals to `select json_unquote(json_extract(a, '$.a'))`.
`select a->'$.a'` equals to `select json_extract(a, '$.a')`; `select a->>'$.a'` equals to `select json_unquote(json_extract(a, '$.a'))`.