lecture 10

Question 1

what is database design?

Answer 1

• they organize information in organizations.
• they help you think about which information is needed for specific processes.

Question 2

what should a database do?

Answer 2

• enter information only once
• analyze data on different levels
• be fast and flexible

Question 3

what is a database?

Answer 3

a collection of data organized to serve many applications by centralizing data and controlling redundant data. basically, excel sheets connected to other excel sheets.

Question 4

what does a database consist of?

Answer 4

• tables with data
• relationships between tables
• metadata (data that descirbes data)

Question 5

what is a database management system (DBMS)?

Answer 5

• the software you use to manage a database, specialized for storage, manipulation and retrieval of structured data
• separates logical and physical views of data

Question 6

what capabilities do database management systems have?

Answer 6

• data definition capability
• data dictionary
• data manipulation language

Question 7

what is a relational database?

Answer 7

a two-dementional table, each table contains data on one entity and its attributes.

Question 8

what is a table?

Answer 8

a grid of
- rows > records for different instances of an entity
- columns > represents attribute for entity

Question 9

what is the primary key?

Answer 9

field dat uniquely indentifies each record in a table

Question 10

what is a foreign key?

Answer 10

field that is a primary key in another table, used for looking up records for that table and links records together

Question 11

what is a flat-file database?

Answer 11

opposite of the relational database, database has a lot of loss of information, is inconsistent and contains redundant data

Question 12

what is an entity-relationship diagram (ERD)?

Answer 12

illustration of relationships between entities. used by analysts to document the data model

Question 13

what is an entity?

Answer 13

a box with a name that represents something

Question 14

what type of relationships are there?

Answer 14

• one to one (1-1) > vb. lecturer has an office and does not share it with anyone
• one to many (N-1) > vb. lecturer teaches many courses, but a course is only thaugth by one lecturer
• many to many (N-N, N-M) > vb. students follow many courses, courses have many students