Market Share in Fact Table

[exhortae]

Hi,

I wonder if I can put market share values in a fact table. Let me explain myself :

For a university project I have to provide for an automobile company the following values.

- Sells by volumes.
- Market shares.


Sells by volumes is an easy go, but I'm having difficulties with market shares. Do I need to put market shares values in the fact table, or is it better to just calculate them in reports.

Thanks

[VHF]

Percentages don't aggregate well, so it is better to calculate them in the report when possible.

You could store market share in a periodic snapshot fact table, but then you are pretty much locked into the grain of the fact table for reporting purposes because percentages won't correctly add or average when aggregating to a higher summary level. If you calculate the percentage in the report you can provide accurate results at any level of drill-down.