CREATE TABLE student (stuid DECIMAL, lname TEXT, fname TEXT, age DECIMAL, sex TEXT, major DECIMAL, advisor DECIMAL, city_code TEXT)
CREATE TABLE member_of_club (stuid DECIMAL, clubid DECIMAL, position TEXT)
CREATE TABLE club (clubid DECIMAL, clubname TEXT, clubdesc TEXT, clublocation TEXT)

Find the club which has the largest number of members majoring in '600'.
SELECT t1.clubname FROM club AS t1 JOIN member_of_club AS t2 ON t1.clubid = t2.clubid JOIN student AS t3 ON t2.stuid = t3.stuid WHERE t3.major = "600" GROUP BY t1.clubname ORDER BY COUNT(*) DESC LIMIT 1
SELECT "t1"."clubname" FROM "club" AS "t1" JOIN "member_of_club" AS "t2" ON "t1"."clubid" = "t2"."clubid" JOIN "student" AS "t3" ON "600" = "t3"."major" AND "t2"."stuid" = "t3"."stuid" GROUP BY "t1"."clubname" ORDER BY COUNT(*) DESC NULLS LAST LIMIT 1