Any faster way

Question

this is a sample date in my viewobject
id title parentId
1 root -1
2 level2.1 1
3 level2.2 1
4 leaf1 2
5 leaf2 3
the parentID is a foreignkey to id,there is also a view link bettwen them.
i want to load the whole tree,so i must first to iterate the whole viewobjcet to find root.
then when i want to find the root's children,i must also to iterate the whole viewobject.
this is too slow.
how can i make it faster?can i remove the row i have iterated,because it only iterate once.

Answer 1

Hi,
Why not writing your vo query with a connect by clause?
As in
-- Beginning of Sample Data
with t as
select 1 id, 'root' title, -1 parentid from dual
union all select 2, 'level2.1', 1 from dual
union all select 3, 'level2.2', 1 from dual
union all select 4, 'leaf1', 2 from dual
union all select 5, 'leaf2', 3 from dual
) -- End of Sample Data
select id,level, title from t
start with parentid=-1
connect by prior id=parentid
Output
        ID      LEVEL TITLE
         1          1 root
         2          2 level2.1
         4          3 leaf1
         3          2 level2.2
         5          3 leaf2This is just an example, you can change the select statement according to your original table.
-Arun