This VoiceThread lecture covers database design and relational databases. It discusses key concepts like bits, binary digits, what a database is, the cabinet analogy, advantages and disadvantages of database management systems, types of databases including relational and object-oriented, types of relationships in relational databases, database normalization process, and entity relationship diagrams. The lecture is intended to make up for a missed class on database design topics.

1. This 2nd VoiceThread is to
makeup for the missed
Feb. 2nd class
Topic: Database Design
By: George Saban

2. Intro to Database
• Binary Digits = bits
• US statistician John Tukey invents the term "bit" (binary digit, 0 or 1) for the
smallest element of information to describe a two-state system.

3. What is a Database?

4. From bits to Database

5. The Cabinet Analogy

6. Pros and Cons of DBMS
• Advantages of database processing
• Getting more information from the same amount of data.
• Sharing data.
• Balancing conflicting requirements.
• Controlling redundancy.
• Facilitating consistency.
• Improving integrity.
• Expanding security.
• Increasing productivity.
• Providing data independence.
• Disadvantages of database processing
• Larger file size.
• Increased complexity.
• Greater impact of failure.
• More difficult recovery.

7. Types of Databases
• 1. Hierarchical
• 2. Network
• 3. Relational *
• 4. OO DB
• 5. Hybrid

8. Relational Database (RDBMS)
• A collection of interrelated tables.
• Types of Relationships: (next slides)

9. Types of Relationships
• One-to-one relationship

10. Types of Relationships
• One-to-many relationship

11. Types of Relationships
• Many-to-many relationship

12. So What?
• Smallest unit of data
• Relationship between a record and an object

13. The Request/Response Cycle

14. The Big Picture: Business Process Model

15. Types of Keys
• Primary key – is an attribute or set of attributes that will uniquely identify records
in a table. Example: social-security number, driver license, employee-ID, unique
sequence number, etc.
• Secondary key – a non-key field that could potentially be used as the primary key.
Example: product-ID, UPC-code, etc. This is similar to an alternate key.
• Alternate key – a non-key field that could potentially be used as the primary key.
Example: product-ID, UPC-code, etc. This is similar to a secondary key.
• Candidate key – the same as secondary key and alternate key.
• Foreign key – it is a non-key field in a table but is actually a primary key of another
table. It exists as a link (to maintain relation) between the two tables.
• Non-primary key or non-prime attribute – is an attribute or attributes that is
neither a primary key nor a candidate key. Example: first name, address, etc.
• Combination key – is a primary key made up of multiple keys. Example: StudentID
+ lastname + firstname.

16. The Normalization Process
• Step I: Write down all the fields needed to support your application.
• Step II: Think if these fields repeat or not. And eliminate fields that can be calculated.
• Step III: Yank out fields that repeat and store it in a separate table and leave those fields
that does not repeat into this existing table. Group similar fields into a table.
• Step IV: Select the primary key field(s) for each table. And underline the primary key field
(PK).
• Step V: Normalize the table by putting the database in first normal form (or 1NF).
Meaning, tables should have no repeating fields.
• Step VI: Continue normalization process by putting the database in second normalized
form (or 2NF). Meaning, all non-key fields on a table should be dependent on the entire
primary key fields and not just part of it. The table should be already in 1NF and the
primary key field should be a combination key field.
• Step VII: Continue normalization process by putting the database in its third normalized
form (or 3NF). Meaning, all non-key fields should not be dependent on another non-key
field. The table should be already in 2NF.
• Step VIII: Assign names to these tables.
• Step IX: Draw table relationships, also called entity relationship diagram (ERD).

17. Entity Relationship Diagram (ERD)
• Note the interrelationships
of tables: a database.
• When asked to
draw/design a DB—draw
an ERD.

18. Thank You!
• Thank you for your patience and for being flexible in making up the
missed classes.
• Comment in as many slides to earn full credit for Week #6.
• Please make sure you digested all the artifacts posted in Canvas under
Week #6.
• Complete also the deliverable for the week.
• I hope to see you on Week #7 to have a conversation regarding
development strategies.