“A bird does not sing because it has the answers, it sings because it has a song.”
DISTINCT eliminates duplicates from returning in the Answer Set.
Both examples produce the exact same result
Rules for Distinct Vs. GROUP BY
(1) Many Duplicates – use GROUP BY
(2) Few Duplicates – use DISTINCT
(3) Space Exceeded - use GROUP BY
Distinct and GROUP BY in the two examples return the same answer set.