Table schema:
CREATE TABLE table_20466963_4 (guest_2 VARCHAR, guest_4 VARCHAR, guest_3 VARCHAR)

Question: Who is the guest 2 in the episode where guest 4 is Iyare Igiehon and guest 3 is John Oliver?
SQL: SELECT guest_2 FROM table_20466963_4 WHERE guest_4 = "Iyare Igiehon" AND guest_3 = "John Oliver"