Who had the pole position on 7 August?
CREATE TABLE "race_calendar_and_winners" (
  "round" real,
  "circuit" text,
  "date" text,
  "pole_position" text,
  "fastest_lap" text,
  "winning_driver" text,
  "winning_team" text
);
SELECT "pole_position" FROM "race_calendar_and_winners" WHERE "date"='7 august';