Inheriting the values in tree structure

Question

In the below graph if P1 value is 10 then all node value should be 10.
But at any level of node we can change the value of node for example
If I override P6 with value 20 then p6, p7, p8 values should be 20 and remainings with 10
P1 10
P2 P3 10
30 P4 P5 10
P6 20
P7 P8 20
Expecting output :
P1 10
P2 10
P3 10
P4 30
p5 10
p6 20
p7 20
p8 20
am having a table which stores this hierarchies
Table : create table Prod_Hierarchy
( child_node varchar2(10) ,parent_node varchar2(10))
With values
Child_node, Parent_node
P1
P2 P1
P3 P1
P4 P2
p5 p2
p6 p5
p7 p6
p8 p6
And below table is to override the values from inheritence
create table Prod_value ( node varchar2(10), node_val number(10))
values:
P1 10
p4 30
P6 20

Answer 1

What about this solution.
Processing ...
create table members (
     id number,
     value number,
     change_id number
Processing ...
create sequence change_id start with 1 increment by 1 nocache
Processing ...
create or replace trigger register_modification
before insert or update on members for each row
begin
     select change_id.nextval
     into :new.change_id
     from dual;
end;
TRIGGER REGISTER_MODIFICATION compiled successfully
Processing ...
insert into members (id,value) (
     select rownum id, trunc(dbms_random.value(1,5)) * 10 as value
     from dual
     connect by rownum <= 15
15 row(s) inserted
Processing ...
create table relations as
     select rownum id,decode(rownum,1,null,trunc(dbms_random.value(1,rownum))) parent
     from dual
     connect by rownum <= 15
Processing ...
select parent,id,value
from members join relations using (id)
Query finished, retrieving results...
                 PARENT                                    ID                                    VALUE                
                                                                              1                                     40
1                                                                             2                                     40
2                                                                             3                                     20
3                                                                             4                                     10
1                                                                             5                                     20
2                                                                             6                                     10
6                                                                             7                                     30
5                                                                             8                                     30
1                                                                             9                                     30
5                                                                            10                                     30
5                                                                            11                                     20
7                                                                            12                                     10
9                                                                            13                                     20
9                                                                            14                                     20
3                                                                            15                                     40
15 row(s) retrieved
Processing ...
select parent,id,value
from members join relations using (id)
model
     reference get_parent on (
          select parent,id
          from relations
     dimension by (id)
     measures (parent as p) ignore nav
     main result
     dimension by (id,parent)
     measures (value,change_id,change_id as vtg)
     rules automatic order (
          vtg[any,any] = case
               when vtg[cv(parent),p[cv(parent)]] > vtg[cv(),cv()] then
                    vtg[cv(parent),p[cv(parent)]]
               else
                    vtg[cv(),cv()]
          end,
          value[any,any] = case
               when vtg[cv(),cv()] > change_id[cv(),cv()] then
                    value[cv(parent),p[cv(parent)]]
               else
                    value[cv(),cv()]
          end
Query finished, retrieving results...
                 PARENT                                    ID                                    VALUE                
                                                                              1                                     40
1                                                                             2                                     40
2                                                                             3                                     20
3                                                                             4                                     10
1                                                                             5                                     20
2                                                                             6                                     10
6                                                                             7                                     30
5                                                                             8                                     30
1                                                                             9                                     30
5                                                                            10                                     30
5                                                                            11                                     20
7                                                                            12                                     10
9                                                                            13                                     20
9                                                                            14                                     20
3                                                                            15                                     40
15 row(s) retrieved
Processing ...
update members
set value = 15
where id = 2
1 row(s) updated
Processing ...
select parent,id,value
from members join relations using (id)
model
     reference get_parent on (
          select parent,id
          from relations
     dimension by (id)
     measures (parent as p) ignore nav
     main result
     dimension by (id,parent)
     measures (value,change_id,change_id as vtg)
     rules automatic order (
          vtg[any,any] = case
               when vtg[cv(parent),p[cv(parent)]] > vtg[cv(),cv()] then
                    vtg[cv(parent),p[cv(parent)]]
               else
                    vtg[cv(),cv()]
          end,
          value[any,any] = case
               when vtg[cv(),cv()] > change_id[cv(),cv()] then
                    value[cv(parent),p[cv(parent)]]
               else
                    value[cv(),cv()]
          end
Query finished, retrieving results...
                 PARENT                                    ID                                    VALUE                
                                                                              1                                     40
1 2 15
2 3 15
3 4 15
1                                                                             5                                     20
2 6 15
6 7 15
5                                                                             8                                     30
1                                                                             9                                     30
5                                                                            10                                     30
5                                                                            11                                     20
7 12 15
9                                                                            13                                     20
9                                                                            14                                     20
3 15 15
15 row(s) retrievedOn the table reporting values of nodes there is a number that tells in with order the value of node has been updated.
Then with the model query latest changes are inherieted by child nodes.
Bye Alessandro