create or replace function f1(p varchar2) return varchar2 is
begin
   dbms_lock.sleep(1);
   return p||'-'||to_char(sysdate,'hh24:mi:ss');
end;
/
create or replace function f1d(p varchar2) return varchar2 deterministic is
begin
   dbms_lock.sleep(1);
   return p||'-'||to_char(sysdate,'hh24:mi:ss');
end;
/
col res for a10;
set timing on;
with v as (
        select 1 n
        from dual 
        connect by level<=5
        union all
        select 2
        from dual 
        connect by level<=5
)
select
  n, 'f1' f,f1(n) res
from v
union all
select 
  n, 'f1d' ,f1d(n) res
from v
/

SQL> create or replace function f1(p varchar2) return varchar2 is
  2  begin
  3     dbms_lock.sleep(1);
  4     return p||'-'||to_char(sysdate,'hh24:mi:ss');
  5  end;
  6  /

Function created.

SQL> create or replace function f1d(p varchar2) return varchar2 deterministic is
  2  begin
  3     dbms_lock.sleep(1);
  4     return p||'-'||to_char(sysdate,'hh24:mi:ss');
  5  end;
  6  /

Function created.

SQL> col res for a10;
SQL> set timing on;
SQL> with v as (
  2          select 1 n
  3          from dual
  4          connect by level<=5
  5          union all
  6          select 2
  7          from dual
  8          connect by level<=5
  9  )
 10  select
 11    n, 'f1' f,f1(n) res
 12  from v
 13  union all
 14  select
 15    n, 'f1d' ,f1d(n) res
 16  from v
 17  /

         N F   RES
---------- --- ----------
         1 f1  1-20:49:41
         1 f1  1-20:49:42
         1 f1  1-20:49:43
         1 f1  1-20:49:44
         1 f1  1-20:49:45
         2 f1  2-20:49:46
         2 f1  2-20:49:47
         2 f1  2-20:49:48
         2 f1  2-20:49:49
         2 f1  2-20:49:50
         1 f1d 1-20:49:51
         1 f1d 1-20:49:51
         1 f1d 1-20:49:51
         1 f1d 1-20:49:51
         1 f1d 1-20:49:51
         2 f1d 2-20:49:52
         2 f1d 2-20:49:52
         2 f1d 2-20:49:52
         2 f1d 2-20:49:52
         2 f1d 2-20:49:52

20 rows selected.

Elapsed: 00:00:12.01

declare 
  n1 int;
  n2 int;
  oper_date date;
  qnt0  number;
begin
   SELECT sq_ttt.nextval into n1 FROM dual;
   
   SELECT v.dat.oper_date, v.dat.qnt0
     into oper_date,qnt0
   FROM
   (
       SELECT
         value(test_TYPE_DATA_QNT) as dat 
       FROM dual
       where rownum > 0
   ) v;
   SELECT sq_ttt.currval into n2 FROM dual;
   dbms_output.put_line(n1||' '||n2);
end;
/