CREATE TABLE "dvd_releases" (
  "volume" text,
  "discs" real,
  "episodes" real,
  "region_1_release" text,
  "region_2_release" text,
  "region_4_release" text
);

Question: What is the region 4 release that has july 20, 2009 as the region 2?
SQL: SELECT "region_4_release" FROM "dvd_releases" WHERE "region_2_release"='july 20, 2009';

Question: What is the region 1 release that has july 20, 2009 as the region 2?
SQL: SELECT "region_1_release" FROM "dvd_releases" WHERE "region_2_release"='july 20, 2009';

Question: What is the average episode that has September 11, 2007 as a region 1?
SQL: SELECT AVG("episodes") FROM "dvd_releases" WHERE "region_1_release"='september 11, 2007';