Database: olympics
Question: Provide the names of competitors who received a gold medal.
SQL: SELECT DISTINCT T1.full_name FROM person AS T1 INNER JOIN games_competitor AS T2 ON T1.id = T2.person_id INNER JOIN competitor_event AS T3 ON T2.id = T3.competitor_id INNER JOIN medal AS T4 ON T3.medal_id = T4.id WHERE T4.medal_name = 'Gold'