This week's BI is mainly about Data Warehouse. This week's lecture also showed the difference between DBMS, OLAP and Data Mining. We also learnt something called the Data Mart, which is something like a smaller version of the Data Warehouse, and it caters to one department, for example sales. A few of the data marts can make up to a data warehouse.
The various schemas are revisited this week while more in-depth. Even though this is learnt during Data Mining, i have completely forgotten what this is about. http://en.wikipedia.org/wiki/Star_schema
There is also something called the parent child dimensions and slowly changing dimensions(SCD). The former is based on two dimension table columns that together define the relationships among the members of the dimension. SCD is dimensions that change over time, for example salesperson moving from one sales territory to another. There will be changes to organisation chart as employees are promoted or resigned. There are a total of 3 types of SCDs.
We also learnt about Relational OLAP(ROLAP), Multidimensional OLAP(MOLAP) and Hybrid OLAP(HOLAP) and the differences.
http://en.wikipedia.org/wiki/ROLAP
http://en.wikipedia.org/wiki/MOLAP
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