What was the margin of victory at the Texas International Open?
CREATE TABLE "pga_tour_wins_6" (
  "date" text,
  "tournament" text,
  "winning_score" text,
  "margin_of_victory" text,
  "runner_s_up" text
);
SELECT "margin_of_victory" FROM "pga_tour_wins_6" WHERE "tournament"='texas international open';