What rank was Core Districts + Inner Suburbs and had a population of 10123000?
CREATE TABLE "largest_cities_proper_by_population" (
  "rank" real,
  "city" text,
  "population" text,
  "definition" text,
  "country" text
);
SELECT MAX("rank") FROM "largest_cities_proper_by_population" WHERE "definition"='core districts + inner suburbs' AND "population"='10123000';