user: Question: Who had the fastest lap when Al Unser won?
Columns: ['Name', 'Pole Position', 'Fastest Lap', 'Winning driver', 'Winning team', 'Report']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Kraco Dixie 200', 'Rick Mears', '26.730', 'Gordon Johncock', 'Patrick Racing', 'Report']
SQL:

assistant: SELECT "Fastest Lap" FROM "Table" WHERE "Winning driver" = 'Al Unser';