Postgresql East Philadelphia, PA Databases – A Historical Perspective

Part Two Why be normal? Databases – A Historical Perspective

The Normal Forms Normalization Workshop Databases – A Historical Perspective

Normal Forms The truth, The whole truth, And nothing but the truth. Databases – A Historical Perspective

First Normal Form (1NF) sets the very basic rules for an organized database: 1. Eliminate duplicative columns from the same table. 2. Create separate tables for each group of related data and identify each row with a unique column (the primary key). Databases – A Historical Perspective

Second Normal Form 2NF: 1. Remove subsets of data that apply to multiple rows of a table and place them in separate tables. 2. Create relationships between these new tables and their predecessors through the use of foreign keys. Databases – A Historical Perspective

Third Normal Form: 1. Meet the requirements of both 1NF and 2NF 1NF2NF 2. Remove columns that are not fully dependent upon the primary key.columnsprimary key Databases – A Historical Perspective

4 th and 5 th Normal Form – These are data purity abstractions which are not routinely used in production databases. Databases – A Historical Perspective

6 th Normal Form – Found only in alien databases. Databases – A Historical Perspective

"The key, the whole key, and nothing but the key, so help me Codd." Databases – A Historical Perspective

And, a note about data warehousing… De-normalization is a key tenet of data warehousing. Databases – A Historical Perspective

BRAINSTORM!!! Databases – A Historical Perspective

Questions? Comments? Databases – A Historical Perspective

End Of Part Two Databases – A Historical Perspective