user: Question: Opponents of Sebastián Decoud Santiago Giraldo had what surface?
Columns: ['Date', 'Tournament', 'Surface', 'Partnering', 'Opponents', 'Score']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['April 10, 2006', 'Florianópolis , Brazil', 'Clay', 'Júlio Silva', 'Máximo González Sergio Roitman', '6–2, 3–6, [10–5]']
SQL:

assistant: SELECT "Surface" FROM "Table" WHERE "Opponents" = 'Sebastián Decoud Santiago Giraldo';