CREATE TABLE table_2468961_4 (production_code INT, original_air_date VARCHAR)

What was the production code for the episode that debuted October 1, 1993?
SELECT MAX(production_code) FROM table_2468961_4 WHERE original_air_date = "October 1, 1993"
SELECT MAX("production_code") FROM "table_2468961_4" WHERE "October 1, 1993" = "original_air_date"