Major Description
In Spark, decode(bin, charset) - Decodes the first argument using the second argument character set.
Unfortunately this is NOT what any other SQL vendor understands DECODE to do.
DECODE generally is a short hand for a simple case expression:
SELECT DECODE(c1, 1, 'Hello', 2, 'World', '!') FROM (VALUES (1), (2), (3)) AS T(c1) => (Hello), (World) (!)
