CST 363 Week 4

Week 4

This week was all about normal forms regarding relations in a database. This week was pretty informative for me. I understand most of these aspects and was actually practicing them a lot in my daily life, but I never knew the names for any of these or the defined normal form steps that would help logically break these up. I was just reasoning about it on my own and eventually getting to a databases that are very close to Boyce-Codd normal form (if not, actually in BCNF). We didn't get to the higher normal forms, but hopefully I'll get to dive into that in the future.

For the exercises and assignments this week I utilized the draw functionality in Google Docs and found it extremely useful and will hopefully find more cases to use it in the future. Although, I probably should have started familiarizing myself with Dia. But, I think Dia will be useful for schema diagrams (assuming we're getting there).

The content from this week is exactly the kind of content I was hoping to get out of completing my bachelor's degree. There are so many concepts and theories that I don't feel I was able to fully know from the bootcamp, but this is making me start to feel like I made the right choice in returning to school to get my degree.

Below are the normal forms that we covered and what they indicate for each table.

• First normal form (1NF): A table is in first normal form when there aren't any repeating groups, the keys are defined, and all of the attributes are dependent on the primary key.
• Second normal form (2NF): A table is in second normal form when it meets the requirements of the first normal form and there are no partial dependencies (or no attributes are dependent on a portion of the primary key).
• Third normal form (3NF): A table is in third normal form when it meets the requirements of the second normal form and there are no transitive dependencies (or no non prime attribute depend on another non prime attribute).
• Boyce-Codd normal form (BCNF): A table is in Boyce-Codd normal form when no primary key (or portion of the primary key) depends on any non prime attributes. The book describes this as normal form as "when every determinant in the table is a candidate key."