Databases

Question 1

What is normalisation

Answer 1

Process where you :
- reduce duplication
- reduce inconsistency
- make it easier to search and sort

Question 2

Redundant data

Answer 2

Unnecessary repeated data
- leads to data inconsistency

Question 3

1st normal form

Answer 3

Contains repeating attributes and has a primary key

Question 4

Relational database

Answer 4

Data is stored in separate tables that are linked through primary and foreign keys

Question 5

Flat file

Answer 5

All data is stored in one place
- easy to set up
- main problem = redundant data

Question 6

Primary key

Answer 6

Unique identifyer for a record in a table

Question 7

Foreign key

Answer 7

Links 2 tables together, exists in one table as a primary key and acts as a foreign key in another

Question 8

First normal form

Answer 8

No atttribute that contains more then a single value
- each

Question 9

2nd normal form

Answer 9

Doesn’t have any partial dependencies
No attributes can depend on part of a composite key

Question 10

3rd normal form

Question 11

Secondary key

Answer 11

Is made on a field that you would like to be indexed for faster searches
- a table can have more then 1 secondary key