gistfile1.txt

select    f.foo, f.bar, b.beatle
from      fumble f
left join brox b on b.x = f.x
                and b.y = f.y
                and b.z = f.z
                and b.g = f.g
                and b.h = f.h
                and b.k = f.k
                and b.j = f.j
order by  foo, bar;

=>

with
  fx as (
    select  x, y, z, g, h, k, l, foo, bar,
            concat_ws (':', x, y, z, g, h, k, l) as kfx
    from    fumble
    ),
  bx as (
    select  x, y, z, g, h, k, l, beatle,
            concat_ws (':', x, y, z, g, h, k, l) as kbx
    from    brox
    )
select    foo, bar, beatle
from      fx
left join bx on kbx = kfx
order by  foo, bar;