Question

Is there a pattern that can handle recurring dimension in data warehouse? I’ve got recurring company subjects structure. Sales fact can be assigned at every level. Example

 Company A                  <- sales facts here
    Company A subcompany    <- sales facts here
         Department A1      <- sales facts here
         Department A2      <- sales facts here
 Company B                  <- sales facts here
 Company C                  <- sales facts here
    Company C department    <- sales facts here

While displaying sales fact sum for Company A I want it to be sum of sales of whole tree.

In my relational database I have a parent-child recurring structure. I can’t (or don’t know how) create this kind of structure in data warehouse, as dimensions levels must be defined.

I thought about 3 levels of hierarchy, but some companies doesn’t have departments at all.

I’m using InfiniDB and trying to configure Mondrian and JPalo

Answer 1

Simply de-normalize this into the dimDepartment table

dimDepartment          Example Data
----------------       -------------
DepartmentKey            1234
DepartmentBusinessKey    a_b_a1
Department               A1
SubCompany               B
Company                  A

So for whole company A:

select
    sum(Amount) as TotalSale
  , sum(Taxes)  as TotalTax
from factSale      as f
join dimDepartment as d on d.DepartmentKey = f.DepartmentKey
where Company = 'A' 

for sub-company B of the company A

where Company    = 'A'
  and SubCompany = 'B'

for department A1, sub-company B, company A

where Company    = 'A'
  and SubCompany = 'B'
  and Department = 'A1'

If a company does not have sub-companies, simply use ‘none' or 'main' as a default sub-company name.