我知道如何计算复杂对象的字符串表示的大小。也许这将帮助你得到一些想法，至少如何估计字节大小。
利用变换，我们可以得到字符串表示和检查长度。如果需要utf-8字符长度和utf-8八位字节数，hive2.3有字符长度和八位字节长度。

with data as (
select array(named_struct('key','value', 'key2', 'тест')) as complex_object
)

select complex_object_str, length(complex_object_str) ascii_length, length(cast(complex_object_str as binary)) binary_length
from 
(
select transform(complex_object) using  '/bin/cat' as complex_object_str from data
)s;

结果：

complex_object_str  ascii_length    binary_length   
[{"key":"value","key2":"тест"}] 31  35