Read: 14a - DB Normalization

Database Normalization

• limit tables to one purpose
• this helps with:
  • duplicate data
  • to not have to modify table later
  • make queries easier

    duplicate data

• wastes memory, lowers performance
• more cumbersome to maintain
• difficult to add changes

  Modification Anomolies

• insert issues, whats minimum data for an insert?
• Having to alter duplicated data in all its locations
• Deleteing items removes useful data since it is tied to other elements

  Search and Sort

• If needed data can live in multiple locations search queries are inherently less effecient
• sort by becomes an issue

  Normalize

• “First Normal Form – The information is stored in a relational table with each column containing atomic values. There are no repeating groups of columns.
• Second Normal Form – The table is in first normal form and all the columns depend on the table’s primary key.
• Third Normal Form – the table is in second normal form and all of its columns are not transitively dependent on the primary key”