CREATE TABLE "series_overview" (
  "season" real,
  "network" text,
  "episodes" real,
  "premiered" text,
  "ended" text,
  "dvd_set_release_date" text
);

Question: When dis cbs release the DVD set?
SQL: SELECT "dvd_set_release_date" FROM "series_overview" WHERE "network"='cbs';

Question: What is the total season number for episodes later than episode 30?
SQL: SELECT SUM("season") FROM "series_overview" WHERE "episodes">30;