Can someone please explain to me how you would create a star schema starting with 2 tables, for example a Student table with StudentID, Address, City, State, Zip and class table with description, credits, fees and date?
I understand that you take the primary keys from each table and put them as a foreign key in the facts table, but is there a way to have an actual star with 5 tables, starting with 2 tables?
If I added a table called Professor would that be considered a dimension table or would the date table be a dimension table?
Just to be clear: A Star schema can consist of any number of dimension tables (points of the star). It doesn’t have to be 5.
The facts table represents the relationship or transaction that (as you said) hold foreign keys to all of the other tables. In this case, your facts table would be something like “classesTaken”, “classSection” or “enrollment”. You could also add tables for “Professor” (because each instance of a class will need a professor) and/or a “Date” table (normalized from your Class table) to give enrollment dates.
That would give you a fact table with 4 “points” of a star. If you were really bent on having a schema that resembled a 5-pointed star, I’m sure you could think of another dimension table to add. Hope that helps.