user: Question: What surface was played on against Shahar Pe'er?
Columns: ['Edition', 'Zone', 'Round', 'Date', 'Against', 'Surface', 'Opponent', 'Outcome', 'Result']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [2005.0, 'Europe/Africa Group I C', '1R', '21 April 2005', 'Slovenia', 'Clay', 'Tina Pisnik', 'Loss', '6–0, 6–1']
SQL:

assistant: SELECT "Surface" FROM "Table" WHERE "Opponent" = 'Shahar Pe''er';