question: Who is the guest 2 in the episode where guest 4 is Iyare Igiehon and guest 3 is John Oliver?
answer: SELECT guest_2 FROM table_20466963_4 WHERE guest_4 = "Iyare Igiehon" AND guest_3 = "John Oliver"
context: CREATE TABLE table_20466963_4 (guest_2 VARCHAR, guest_4 VARCHAR, guest_3 VARCHAR)