Drop table parent_mst;
drop table parent_dtl;
drop table p1;
drop table p2;
drop SEQUENCE p_seq;

delete from parent_mst;
delete from parent_dtl;
delete from p1;
delete from p2;

CREATE SEQUENCE p_seq
 START WITH     1
 INCREMENT BY   1;

create table p1
(
grp number(3),
nel number(4)
);
---------
create table p2
(
grp number(3),
per number(4)
);
create table parent_mst
(
grp number(3),
nel number(4),
ppk_seq number(5)
);

create table parent_dtl
(
grp number(3),
per number(4),
ppk_seq number(5)
);

INSERT INTO p1 
SELECT 100  grp, 
       8000 nel 
FROM   dual 
UNION ALL 
SELECT 200  grp, 
       1000 nel 
FROM   dual 
UNION ALL 
SELECT 300  grp, 
       1000 nel 
FROM   dual;

INSERT INTO p2 
SELECT 100, 
       200 
FROM   dual 
UNION ALL 
SELECT 100, 
       300 
FROM   dual 
UNION ALL 
SELECT 100, 
       500 
FROM   dual 
UNION ALL 
SELECT 200, 
       400 
FROM   dual 
UNION ALL 
SELECT 200, 
       600 
FROM   dual 
UNION ALL 
SELECT 500, 
       600 
FROM   dual; 

insert into parent_mst
(select 100,320,10 from dual);

GRP PER ppk_seq

100 200 1
100 300 1 
100 500 1
100 200 2
100 300 2 
100 500 2
200 400 3
200 600 3