bsys 2060 lecture 4, april 12 th
DESCRIPTION
BSYS 2060 Lecture 4, April 12 th. Midterm overview Normalization. Agenda. External events Announcements Midterm format Course questions Normalization Bank database exercise Team project. http://www.vef.org/. http://www.newventuresbc.com/the-competition/about-the-competition/. - PowerPoint PPT PresentationTRANSCRIPT
BSYS 2060Lecture 4, April 12th
Midterm overviewNormalization
Agenda
• External events• Announcements• Midterm format• Course questions• Normalization• Bank database exercise• Team project
http://www.vef.org/
http://www.newventuresbc.com/the-competition/about-the-competition/
Announcements
• If you miss labs because of Easter stat holidays, you need to do the lab exercise outside of regular lab time
• If you miss your Friday lab because of Open House, you can go to one of the other lab slots
Midterm Format: Free range – open book, open Internet… the only un-natural part is you can’t collaborate.
Image source: “truly free range chickens” by Brookford Farm, CC BY 2.0
50% - Multiple Choice, 25 questions worth 2 each50% - Data Modeling question, 1 page
Held during your Week 5 lab
You are writing the questions…
• Each student in their Week 4 lab needs to come up with a multiple choice question
• Question topics assigned by set• Use local context where applicable in your
questions• Use images where applicable• Sample question process
* At least some of them
*
https://zenportfolios.ca/groups/bsys-2060-2012/forum/
https://zenportfolios.ca/bcit-bsys-2060-2012/midterm-question-submission/
Source: http://www.flickr.com/photos/caius/2300154566/
Normalization…
In relational database design, the process of organizing data to minimize redundancy.
Normalization defined:
Source: http://www.webopedia.com/TERM/N/normalization.html
Normalization usually involves dividing a database into two or more tables and defining relationships between the tables.
Why bother?
Source: http://www.webopedia.com/TERM/N/normalization.html
The objective is to isolate data so that additions, deletions, and modifications of a field can be made in just one table and then propagated through the rest of the database via the defined relationships.
Why bother?
Source: http://www.webopedia.com/TERM/N/normalization.html
1. Atomicity & uniqueness… No repeating elements or groups of elements and each row of data must have a unique identifier (i.e. primary key)
First normal form
2. No partial dependencies on a concatenated key
Second normal form
3. No dependencies on non-key attributes
Third normal form
An example… orders
1. Atomicity & uniqueness… No repeating elements or groups of elements and each row of data must have a unique identifier (i.e. primary key)
First normal form
So far, it doesn’t meet criteria for 1NF
2. No partial dependencies on a concatenated key
Second normal form
Summary