0

i would like to simulate what-if analysis on a OLAP cube For example, i would like to know the impact on departmental resource budgets by moving employees between departments or the movement in cost of manufacture if a product is moved from one factory to another.

so should i use an rolap cube'mondrian' or molap ?

i will greatful if you can give me some exemple , tuto ... ;) thank you in advance

Chikawi
  • 1
  • 4

2 Answers2

1

Actually mondrian does support "writeback" (via olap4j) so you can do what if analysis. Check out Saiku - AFAIK it's the first and only tool to have implemented it so far.

Here is how it works - it's pretty rudimentary:

http://julianhyde.blogspot.co.uk/2009/06/cell-writeback-in-mondrian.html

Martin is close to the point though, it doesn't actually update the raw data, only objects in the cache. But you wouldnt want to update raw data if you were doing what if analysis anyway!

Codek
  • 5,114
  • 3
  • 24
  • 38
  • Thanks for your response , 1/ i consulted the saiko's demo (http://dev.analytical-labs.com/) but i didn't notice how he supports what-if analysis 2/the link is intressting but in my project i had to do a little more complex what-if analysis not just write back on cells for exemple --> knowing the impact on departmental resource budgets by moving employees between departments or moving product from one factory to another ...#i am newbie on olap analysis so i count on your help. – Chikawi Mar 01 '13 at 13:27
  • I'm not sure mondrian will be able to do that then. It may be you would have to implement a way to actually apply those changes to the data and then use mondrian. As for write back, i havent tried it recently, you could always drop into ##saiku on Freenode IRC and ask them there. – Codek Mar 01 '13 at 13:46
  • I appreciate your help dear Codek, i read in some artcile that i can do this kind of operation using MOLAP server --> Palo. so if you have any idea please let me know it. – Chikawi Mar 01 '13 at 13:59
  • Sorry, can't help you with that one! – Codek Mar 01 '13 at 15:37
0

I would say that Mondrian is an engine to query an existing database that is has a dedicated structure for Olap (usually some kind of star schema).

It is definitely not something to manipulate (or even) change data. Since each what-if analysis needs to change data in some way or another, Mondrian is not the tool for it.

Martin Loetzsch
  • 587
  • 5
  • 12