select ...
from TABLE_NAME t
start with t.id_main is null
connect by t.id_main = prior t.id_subbordinate and t.d_start <= SYSDATE

select ...
       , max(tl.d_start) OVER (PARTITION BY tl.id_e, tl.id_division) AS max_d_start
       , LEAD(tl.d_start,  1 ) OVER (PARTITION BY tl.id_division ORDER BY t1.d_start) AS d_end
       , count(distinct tl.id_e) OVER (PARTITION BY tl.id_division) AS cnt_emp_in_division
       , DENSE_RANK() OVER (PARTITION BY NVL(usls.id_d, lsQ.id_d)
                                         , NVL(usls.id_source, lsQ.id_source)
                                         , NVL(usls.idg_post, lsQ.idg_post)
                                         , s.id_staff
                            ORDER BY abs(lsQ.payment_category-s.category_ets) ASC, lsQ.payment_category DESC) rank_in_group

from ...

select ...     
from table1 t1,
     table2 t2,   
     table3 t3
where t1.id = t2.id
      and t2.id = t3.id (+)

SYSDATE
MONTHS_BETWEEN
ADD_MONTHS
TO_CHAR
TO_NUMBER
TO_DATE
и т.д.

select s.* 
from table s
where s.id_metaterm in (select r.id_metaterm from table(access_pk.Get_MT_CurrentUser('270,271',  0 )) r )