DATABASE NORMALISATION

Domain	Definition
Computing	Database normalisation A series of steps followed to obtain a database design that allows for efficient access and storage of data in a relational database. These steps reduce data redundancy and the chances of data becoming inconsistent. A table in a relational database is said to be in normal form if it satisfies certain constraints. Codd's original work defined three such forms but there are now five generally accepted steps of normalisation. The output of the first step is called First Normal Form (1NF), the output of the second step is Second Normal Form (2NF), etc. First Normal Form eliminates repeating groups by putting each into a separate table and connecting them with a one-to-many relationship. Second Normal Form eliminates functional dependencies on a partial key by putting the fields in a separate table from those that are dependent on the whole key. Third Normal Form eliminates functional dependencies on non-key fields by putting them in a separate table. At this stage, all non-key fields are dependent on the key, the whole key and nothing but the key. Fourth Normal Form separates independent multi-valued facts stored in one table into separate tables. Fifth Normal Form breaks out data redundancy that is not covered by any of the previous normal forms. (http://home.earthlink.net/~billkent/Doc/simple5.htm). [What about non-relational databases?] (1999-05-05). Source: The Free On-line Dictionary of Computing.
Source: compiled by the editor from various references; see credits.

Hexadecimal (or equivalents, 770AD-1900s) (references)

44 41 54 41 42 41 53 45 4E 4F 52 4D 41 4C 49 53 41 54 49 4F 4E

Leonardo da Vinci (1452-1519; backwards) (references)

Binary Code (1918-1938, probably earlier) (references)

01000100 01000001 01010100 01000001 01000010 01000001 01010011 01000101 00100000 01001110 01001111 01010010 01001101 01000001 01001100 01001001 01010011 01000001 01010100 01001001 01001111 01001110

HTML Code (1990) (references)

&#68 &#65 &#84 &#65 &#66 &#65 &#83 &#69 &#32 &#78 &#79 &#82 &#77 &#65 &#76 &#73 &#83 &#65 &#84 &#73 &#79 &#78

ISO 10646 (1991-1993) (references)

0044 0041 0054 0041 0042 0041 0053 0045 004E 004F 0052 004D 0041 004C 0049 0053 0041 0054 0049 004F 004E

Encryption (beginner's substitution cypher): (references)

Expression	Frequency per Day
database normalisation	4
Source: compiled by the editor from various references; see credits.

DATABASE NORMALISATION

Specialty Definition: DATABASE NORMALISATION

Computing

Crosswords: DATABASE NORMALISATION

Frequency of Internet Keywords: DATABASE NORMALISATION

database normalisation

Alternative Orthography: DATABASE NORMALISATION

44 41 54 41 42 41 53 45 4E 4F 52 4D 41 4C 49 53 41 54 49 4F 4E

01000100 01000001 01010100 01000001 01000010 01000001 01010011 01000101 00100000 01001110 01001111 01010010 01001101 01000001 01001100 01001001 01010011 01000001 01010100 01001001 01001111 01001110

&#68 &#65 &#84 &#65 &#66 &#65 &#83 &#69 &#32 &#78 &#79 &#82 &#77 &#65 &#76 &#73 &#83 &#65 &#84 &#73 &#79 &#78

0044 0041 0054 0041 0042 0041 0053 0045 004E 004F 0052 004D 0041 004C 0049 0053 0041 0054 0049 004F 004E

3835543536355339248495247354643533554434948

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