CREATE TABLE "dvd_releases" (
  "dvd_title" text,
  "no_of_discs" real,
  "year" text,
  "no_of_episodes" real,
  "region_1" text,
  "region_2" text,
  "region_4" text
);

Question: What is the largest number of episodes for a 1989 season dvd release? 
SQL: SELECT MAX("no_of_episodes") FROM "dvd_releases" WHERE "year"='1989';

Question: How many  dvd  titled "series 5" were released having a release date or a non available date in region 2?
SQL: SELECT COUNT("region_2") FROM "dvd_releases" WHERE "dvd_title"='Series 5';