English Mixed Chinese Substring

[Dong Bo 董博]

Hi Forks,

Impala treats Chinese word as 3 letters , for English word 1 letter, Is there 
any settings to make it easy to substring a mixed String just like what hive 
does?

Eg :  select substr('test测试test', 1 ,5 ) ,
returns :  test测  ,  NOT : test�


Thanks
Carl