A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Types of Normalisation

1NF: First Normal Form
1NF: First Normal Form

Explains first normal form (1NF) in database design. An example of how to bring the database table structure to 1st normal form is shown.

source: 1keydata.com
2NF: Second Normal Form
2NF: Second Normal Form

Explains second normal form (2NF) in database design. An example of how to bring the database table structure to 2nd normal form is shown. An example of how to bring the database table structure to 2nd normal form is shown.

source: 1keydata.com
3NF: Third Normal Form
3NF: Third Normal Form

The third post focused on the second normal form, its definition, and examples to hammer it home. Once a table is in second normal form, we are guaranteed that every column is dependent on the primary key, or as I like to say, the table serves a single purpose.

BCNF: Boyce–Codd Normal Form
BCNF: Boyce–Codd Normal Form

The normalization process brings order to your filing cabinet. You decide to conform to certain rules where each fact is stored. Today we cover the Boyce-Codd normal form (BCNF), one of the go-to normal forms nowadays.

source: vertabelo.com
EKNF: Elementary key Normal Form
EKNF: Elementary key Normal Form

Elementary key normal form (EKNF) is a subtle enhancement on third normal form, thus EKNF tables are in 3NF by definition. This happens when there is more than one unique compound key and they overlap. Such cases can cause redundant information in the overlapping column(s).

ETNF: Essential Tuple Normal Form
ETNF: Essential Tuple Normal Form

and join dependencies. ETNF lies strictly between fourth normal form and fth normal form (5NF, also known as projection-join normal form). We show that ETNF, al-though strictly weaker than 5NF, is exactly as e ective as 5NF in eliminating redundancy of tuples. Our de nition of ETNF is semantic, in that it is de ned in terms of tuple redundancy.

Fourth Normal Form
Fourth Normal Form

Fourth normal form (4NF) is a level of database normalization where there are no non-trivial multivalued dependencies other than a candidate key. It builds on the first three normal forms (1NF, 2NF and 3NF) and the Boyce-Codd Normal Form (BCNF).

UNF: Unnormalized Form
UNF: Unnormalized Form

Un-Normalised Form (UNF) To produce the Un-Normalised Form (UNF)of an entity we must: list the attributes of the entity; identify the main key; identity the repeating group of attributes; identify its key; We carry out the process using a special document, as shown below.

source: sqa.org.uk