Lec 6

Question 1

Three concepts (data first)

Answer 1

Data -> Context -> Knowledge

Question 2

In Regional databases
Collumns are called:
Rows are called:

Answer 2

1. Attributes

2. Records

Question 3

Database normalization trade-offs

Answer 3

Performance vs Unnecessarily/size

Question 4

1NF requirments

Answer 4

1. Domain only atomic values

2. Single Value

Question 5

2NF requirments

Answer 5

1. 1NF

2. IF! composite key, no partial dependencies

Question 6

3NF

Answer 6

1. 2NF

2. No transitive dependencies

Question 7

An ERD is based on four elemental concepts

Answer 7

– Entities
– Attributes
– Relationships
– Cardinalities

Question 8

Cardinalities forms

Answer 8

1. 1 to 1
2. 1 to M
3. M to N

Question 9

SQL Commands Categories

Answer 9

1. Data Defining Language (Structure)
Create/Delete/Alter databases/tables
2. Data Manipulation Language (Content)
Retrieve/Insert/Change Tuples/Records
3. Data Control Language (Access)
Permission Management