**Quick overview 1NF-3NF** Data normalization exists in multiple levels, according to multiple rules. Normalization reduces data redundancy and increases data integrity. Informally, the cutoff for "well-normalized" is between 3NF and 4NF. Eventually, 6th Normal Form is what you'd call a whole host of Key-Value pairs, where the key is a [[Primary Key]] (this is known as a "Columnar data store"). For well-Normalized data... put simply: > Every non-key attribute > - depends on the key (1st normal form) > - the whole key (2nd normal form) > - and nothing but the key (3rd normal form) > <cite>Colorado State Paper</cite> Unnormalized Data - anything goes First Normal Form (1NF) - Cells contain only one value Second Normal Form (2NF) - Cells contain only one value - All non-Prime fields are functionally dependent on the whole primary key Third Normal Form (3NF) - Cells contain only one value - All non-Prime fields are functionally depending on the whole primary key - All non-Prime fields are independent of each other **** # More ## Source [Relational Database Schema Design Overview](https://medium.com/@kimtnguyen/relational-database-schema-design-overview-70e447ff66f9) [Database normalization](https://en.wikipedia.org/wiki/Database_normalization) [](https://www.cs.colostate.edu/~cs430dl/yr2020su/more_examples/Ch8/Identifying%20Normal%20Forms.pdf) ## Related - [[Relational Databases]] - [[Primary Key]] - [[Prime Attributes]] - [[Superkey]] - [[Composite Key]]