Getting counts/totals at each level of a hierarchical query using CONNECT BY

Question

I am having a heck of a time with this. I am trying to write a query (using Oracle), against a table with a recursive relationship (hierarchical) and get the total number of re

Answer 1

This one is pretty straightforward:

09:38:54 HR@vm_xe> l                                      
  1  select sys_connect_by_path(dp.dir_name, '/') path    
  2         ,(select count(file_id)                       
  3             from dirs dc                              
  4                  ,files f                             
  5            where f.dir_id(+) = dc.dir_id              
  6          connect by prior dc.dir_id = dc.parent_dir_id
  7            start with dc.dir_id = dp.dir_id           
  8          ) count                                      
  9    from dirs dp                                       
 10    connect by prior dp.dir_id = dp.parent_dir_id      
 11*   start with dp.parent_dir_id is null                
09:38:55 HR@vm_xe> /                                      

PATH                                COUNT                 
------------------------------ ----------                 
/ROOT                                   6                 
/ROOT/DIR1_1                            4                 
/ROOT/DIR1_1/DIR2_1                     1                 
/ROOT/DIR1_1/DIR2_2                     3                 
/ROOT/DIR1_2                            2                 

5 rows selected.                                          

Elapsed: 00:00:00.02                                      

Answer 2

select sys_connect_by_path(D.dir_name, '/'), S.count_distinct_file_id
from DIRS D
inner join (select subtree_root_dir_id
            , count(distinct file_id) count_distinct_file_id
        from (select distinct connect_by_root D.DIR_ID subtree_root_dir_id
                    , F.file_id 
                from DIRS D
                left outer join FILES F on F.dir_id = D.dir_id
                start with 1=1 connect by prior D.dir_id = D.parent_dir_id)
        group by subtree_root_dir_id) S
    on D.dir_id = S.subtree_root_dir_id
start with D.dir_id = 1 connect by prior D.dir_id = D.parent_dir_id

Gives the results you asked for, but my gut says I am not seeing something, and that the query can be much simpler. (Please do not accept this answer until a few days have passed, in hopes that some one submits a better answer.)