10/6/15
Muddiest Points for Week 5

1. In the lecture you mentioned that instead of having a primary key, more than one can be compounded. How does that work? Wouldn't it be necessary to focus on one at a time?
2. Is a key the same thing as an entity? I am having trouble seeing a difference between the two.
3. I understand that the same exact form of SQL can't be used in every database. But: what forms of the language stay the same when the changes are made? I guess another way of asking the question is what makes it SQL, then? As opposed to some other language?

My notes on the readings for Week 6 are above these questions.