Pick a random attribute from group in Redshift

Question

I have a data set in the form.

id  |   attribute
-----------------
1   |   a
2   |   b
2   |   a
2   |   a
3   |   c

Desired output:

Answer 1

This solution, inspired by Masashi, is simpler and accomplishes selecting a random element from a group in Redshift.

SELECT id, first_value as attribute 
FROM(SELECT id, FIRST_VALUE(attribute) 
    OVER(PARTITION BY id ORDER BY random() 
    ROWS BETWEEN unbounded preceding AND unbounded following) 
    FROM dataset) 
GROUP BY id, attribute ORDER BY id;