How to append one column to an existing array column in Hive?

[Rex X]

For example, to append columnA to an existing array-type column B

    select
    string_column_A,
    array_column_B,
    *append(array_column_B, string_column_A) as AB*
    from onetable;

I did not find any append function as above in Hive.

To be more accurate, I should say "set" instead of "array" above, since I
expect no duplicates. But the duplication here is not a big deal.

What's the best way to make this in Hive? I have checked the hive
documentation, but cannot find any relevant information to do this.