Which is the largest area in Greenville County, by square mile?
CREATE TABLE "counties" (
  "county" text,
  "year_founded" text,
  "county_seat" text,
  "2010_census_population" real,
  "july_1_2012_population_estimate" real,
  "area_sq_mi" real,
  "land_area_sq_mi" real
);
SELECT MAX("area_sq_mi") FROM "counties" WHERE "county"='greenville county';