CREATE TABLE list (lastname CLOB, firstname CLOB, grade NUMBER, classroom NUMBER)
CREATE TABLE teachers (lastname CLOB, firstname CLOB, classroom NUMBER)

Find the name of the teacher who teaches the largest number of students.
SELECT T2.firstname, T2.lastname FROM list AS T1 JOIN teachers AS T2 ON T1.classroom = T2.classroom GROUP BY T2.firstname, T2.lastname ORDER BY COUNT(*) DESC LIMIT 1
SELECT "T2"."firstname", "T2"."lastname" FROM "list" "T1" JOIN "teachers" "T2" ON "T1"."classroom" = "T2"."classroom" GROUP BY "T2"."firstname", "T2"."lastname" ORDER BY COUNT(*) DESC FETCH FIRST 1 ROWS ONLY