Question

What would make the best dimension tables for example a Student table with StudentID, Address, City, State, Zip and class table with description, credits, fees and date. The reports will be done for the year and the term. Would I put term and year in the facts table or do I make term and facts a dimension table? I guess what I am most confused about is what makes a good dimension table and why.

Answer 1

The SIS that I work on has this basic structure:

id_rec – fact table – contains person information – id, address, city, state, zip, etc…

cw_rec – fact table – contains course enrollment records by year, term and id – id & crs_no foreign keys to id_rec and crs_rec respectively

crs_rec – dimensional table – contains course detail information – course number, course title, credits, fees, etc…

I guess the answer to your question is that you want two fact tables and one dimension table. The fact tables are the id_rec and the cw_rec. The dimension table is the crs_rec

You could add more fact tables to allow for more detail, but you should at least have this basic structure to account for the data fields and requirements you described

From what I understand, you use dimension tables to help describe the facts in the fact tables. The data in dimension tables should not serve to identify facts, but to help describe them