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TM1 - re-ordering dimensions

Posted: Thu Aug 12, 2021 1:10 pm
by richlion2
Hello,

I found this site that does explain what should be the proper order of the dimension be when re-ordering.
https://exploringtm1.com/setting-tm1-cu ... ion-order/

• Firstly order dimensions from smallest to largest,
• Then order dimensions from sparsest to densest

Here is their example:
Dimension Size (N elements) Density (1-5)
Year 5 5
Month 13 5
Version 4 3
Rep 300 4
Product 10,000 3
Customer 10,000 1
Measures-Sales 20 5

When I open Architect on my server, I do not see Density, but I do have #Elements. Is this the same?
Does Architect have a Density column?

Also, I was told to chose the size order by sorting by Memory size in KB/MB, but in the article above it shows to use N-Elements.

Here is one of my cubes with dimensions:
sample-cube-dim.png
sample-cube-dim.png (25.99 KiB) Viewed 3548 times
So it's a bit confusing, can someone explain?

Thanks
Richard

Re: TM1 - re-ordering dimensions

Posted: Thu Aug 12, 2021 1:24 pm
by PavoGa
I believe Density is the ratio of populated leaf elements to the total leaf elements.

Re: TM1 - re-ordering dimensions

Posted: Fri Aug 13, 2021 4:32 pm
by Steve Rowe
I normally explain density as the liklihood of the next element in the dimension being populated if you keep all the other elements in the data set the same.

So time dimensions are nearly always dense, if I sold something last month then I will probably sell it next month, if a ledger code has been posted to this month (for a given cost centre, etc) then it will be posted to next month.

Product is normally sparse, just because we sold a product in a particular region and period there is no reason to assume the next product in the dimension will also be sold.

HTH