Normalisation

Fiona Faulkner
Flashcards by Fiona Faulkner, updated more than 1 year ago
Fiona Faulkner
Created by Fiona Faulkner over 8 years ago
44
3

Description

A level A Level ICT Flashcards on Normalisation, created by Fiona Faulkner on 05/14/2013.

Resource summary

Question Answer
Give 2 characteristics of a table in 1NF (1st normal form) 1)all data is atomic - cannot besplit up further, e.g. forename/surname 2)there is a primary key in the table 3)there is no repeating data, e.g. fields with the same data in 1 record
Give 2 characteristics of a table in 2NF (2nd normal form) 1)must be in 1NF 2)all non-key fields are dependent on the whole PK field(s)
Give 3 charactersitics of a table in 3NF (3rd normal form) 1)must be in 2NF 2)there is no functional dependency between non-key fields
Give 3 advantages of normalisation 1)removes redundant (repeated) data (data is only stored once) 2)less storage space needed to store database due to no repeated data 3)easier to add tables or fields to database in future
Give 2 disadvantages of normalisation 1)reduces database performance as more tables=longer to process queries 2)results of historical (old) calculations can't be stored
Show full summary Hide full summary

Similar

FLAT FILE VS RELATIONAL DATABASE
rosiejones
A2 WJEC Networks Quiz
Henry Cookson
Relational Databases
BadSideSecret
Databases
Luke Hashem
Topic 4: Working With ICT - CODE OF CONDUCT
Henry Cookson
Spreadsheet Features
Fiona Faulkner
METHODS OF CONVEYING INFORMATION
Fiona Faulkner
Security Policies
Henry Cookson
TYPES OF SOFTWARE
Fiona Faulkner
FACTORS AFFECTING QUALITY OF INFORMATION
Fiona Faulkner
Computer Science
Bayram Annanurov