Basic of Normalization
Normalization is process of removing all redundancy form database. It is the application of a set of simple rules called first, second & third normal form. When database design is fully normalized ,there is no repletion of data across tables. The advantages of data normalization can be very large in terms of storage space as well Increased efficiency with which data can be updated & maintained. The rules of normalization or normal forms define exactly what kind of information can placed in each table and how this information relates to the fields. When considering normalization some user related consideration include:
- What data should be stored in database?
- How will the user access the database?
- What privileges does the user require?
- How should data be grouped in database?
- What data most commonly accessed?
- How is all data related in database?
- What steps should be taken to ensure accurate data?
Various normal form :
Advantages of Normalization :
- Greater overall database organization will be gained.
- The amount of unnecessary redundant data reduced.
- Data integrity is easily maintained within the database.
- The database & application design processes are much for flexible.
- Security is easier to maintain or manage.
Disadvantages of Normalization :
- The disadvantage of normalization is that it produces a lot of tables with a relatively small number of columns. These column then have to be joined using their primary/foreign key relation ship.
- This has two disadvantages.
- Performance: all the joins required to merge data slow processing & place additional stress on your hardware.
- Complex queries: developers have to code complex queries in order to merge data from different tables.