What is the surface on 15 August 2009?
CREATE TABLE "doubles_25_10_15" (
  "outcome" text,
  "date" text,
  "tournament" text,
  "surface" text,
  "partner" text,
  "opponents" text,
  "score" text
);
SELECT "surface" FROM "doubles_25_10_15" WHERE "date"='15 august 2009';