Question: Who is the guest 2 in the episode where guest 4 is Iyare Igiehon and guest 3 is John Oliver?
Schema: create table table_20466963_4 (guest_2 varchar, guest_4 varchar, guest_3 varchar, PRIMARY KEY (guest_2))
SQL: select guest_2 from table_20466963_4 where guest_4 = "iyare igiehon" and guest_3 = "john oliver"