[CH] Optimize get_json_object nested function calls

[KevinyhZou]

Description

In our online sqls, have some nested get_json_object function calls, like get_json_object(get_json_object(d, '$.a'), '$.b'), and some of them can be optimized to get_json_object(d, '$.a.b'), which can improve the performance

[KevinyhZou]

some nested get_json_object call case can not optimized: select get_json_object(get_json_object('{"a":"{\\\"x\\\":5}"}', '$.a'), '$.x') can not be converted to select get_json_object('{"a":"{\\\"x\\\":5}"}', '$.a.x');

[philo-he]

@KevinyhZou, do you mean their results are different? Seems this is a corner case.

[KevinyhZou]

Yes, it is a corner case. In most cases, it can be converted. @philo-he

[philo-he]

@KevinyhZou, I feel we can merge the patch for both CH backend and velox backend if it's in good shape. If you are afraid of any similar issue, it's ok to keep a config for users to control the use of this optimization. Thanks!

[KevinyhZou]

OK