1.3 Exchanging Data

Question 1

Define Compression

Answer 1

The process used to reduce the storage space required by a file

Question 2

Define Lossy compression

Answer 2

Lossy compression reduces the size of a file while also removing some of its information (information cannot be retained)

Question 3

Define Lossless compression

Answer 3

The original file can be recovered from the compressed version and using lossy compression reduces the size of the file by completely disregarding some information

Question 4

Define Run Length Encoding

Answer 4

A method of lossless compression in which
repeated values are removed and replaced with one occurrence of the data followed by
the number of times it should be repeated
( AAAAAABBBBBCCC could be represented as A6B5C3)

Question 5

Define Dictionary encoding

Answer 5

Is another example of a method of lossless compression. Frequently occurring pieces of data are replaced with an index and compressed data is stored alongside a dictionary

Question 6

First normal form

Answer 6

No repeating data
Data is atomic
Has a primary key

Question 7

Second normal form

Answer 7

Is in first form

Every key is dependant on the primary key

Question 8

Third normal form

Answer 8

Has no transitive relationship