Database normalization, Advantages of Normalization, Disadvantages of Normalization.
What is database normalization?
Database normalization is a process in which we modify the complex database into a simpler database.
What are the Advantages of normalization?
Data consistency means that the data is always real and it is not ambiguous.
Data becomes nonredundant
Non-redundant means that only copy original copy of data is available for each user and for every time. There are no multiple copies of the same data for different persons. So when data is changed in one file and stay in one file. Then of course data is consistent and non-redundant. Here redundant is not the same as a backup of data, both are different things.
Reduce insertion, deletion and updating anomalies
- Insertion anomaly is an anomaly that occurs when we want to insert data into the database but the data is not completely or correctly inserted in the target attributes. If completely inserted in the database then not correctly entered.
- Deletion anomaly is an anomaly that occurs when we want to delete data in the database but the data is not completely or correctly deleted in the target attributes.
- Update anomaly is an anomaly that occurs when we want to update data in the database but the data is not completely or correctly updated in the target attributes.
Database table compaction
- When we normalize the database, we convert the large table into a smaller table that leads to data and table compaction. Compaction means to have the least and required size.
What are the disadvantages of normalization?
- There is a requirement for an experienced database designer.
- Difficult and expansive
- Requires detailed database design