Easy table transpose in hive

I need to transpose my table. Now i have that type of table:

Atr_1|Atr_2
 A   | 1
 A   | 2

But i want to get the next result

Atr_1|Atr_2|Atr_3
 A   | 1   |  2

How should i transpose my table for achieving this result?

Answer

Use case statements with min() or max() aggregation:

select Atr_1,
       max(case when Atr_2=1 then 1 end ) Attr_2,
       max(case when Atr_2=2 then 2 end ) Attr_3
  from table t
 group by Atr_1;