-- 1. remove rows in T2 that are not in T1
delete T2
where not exists (
    select 1 from T1
    where T1.Ka = T2.Ka and T1.Kb = T2.Kb and ...
--  The where clause can be generated by something like:
--  join(' and ', map { "T1.$_ = T2.$_" } @key_col_names)
)
--  2. synchronize rows that exist in both
update T1
set T1.Va = T2.Va, T1.Vb = T2.Vb, ...
from T1, T2
where T1.Ka = T2.Ka and T1.Kb = T2.Kb and ...
    and ((T1.Va != T2.Va) or (T1.Vb != T2.Vb) ...)
-- Check that your platform supports a "from" clause
-- in update statements.
-- You can actually omit the "value" test; it just eliminates
-- unnecessary data movement.  Beware that nullable columns 
-- need more complicated tests.

-- 3. insert new rows
insert T2 (Ka, Kb, ..., Va, Vb, ...)
select Ka, Kb, ..., Va, Vb, ...
from T1
where not exists (
    select 1 from T2
    where T1.Ka = T2.Ka and T1.Kb = T2.Kb and ...
)