Efficient way to perform approximated search?
I think that what you need to use is a Nonequi join

select *
from
    table_a,
    table_b
where
    table_a.id1 = table_b.id1
    and table_a.id2 = table_b.id2
    and table_a.evnt_sec BETWEEN table_b.evnt_sec -2 and table_b.evnt_sec +2