What surface was played on against Shahar Pe'er?
CREATE TABLE "fed_cup_singles_performances_9" (
  "edition" real,
  "zone" text,
  "round" text,
  "date" text,
  "against" text,
  "surface" text,
  "opponent" text,
  "outcome" text,
  "result" text
);
SELECT "surface" FROM "fed_cup_singles_performances_9" WHERE "opponent"='shahar pe''er';