How to design Table for Cube?

[dlb777]

Hello, I'm newbie in OLAP. I learn OLAP just from the tutorial from the sample database foodmart. I'm confuse.
Because when I saw the Tables from that sample database foodmart, its tables is Denormalize. Example : In "Customer" table there is a field named "CountryID", "CountryName". But there is a table named "Region" which have field "COuntryID", "CountryName".
In RDBMS we use Normalize tables.
My question is, when we design tables for database (we will use it to make a cube in OLAP) do we have to use DENORMALIZE tables, or we use NORMALIZE tables (just like in RDBMS)?
Thanks For Your Answer



Denny

 

[ram1975]

Good question. Whether to denormalize or normalize depends on the amount of data you have. Say for example in the master table if you around 5000 to 10000 rows, you can denormalize that table. Because as compared to the fact table records i.e. say for example 10 million rows, these are very less and hence we don't have to think about more space being taken by the master because of denormalizing.

Why actually we denormalize is to avoid snowflake skema, we can do that.