Learn about the good side of database normalization and the drawbacks of database normalization,
When using a relational database, normalization can help keep the data free of errors and can also help ensure that the size of the database doesn’t grow large with duplicated data. At the same time, some types of operations can be slower in a normalized environment. So, when should you normalize and when is it better to proceed without normalization?
Database normalization is the process of organizing data within a database in the most efficient manner possible. For example, you likely do not want a username stored in several different tables within your database when you could store it in a single location and point to that user via an ID instead.
By keeping the unchanging user ID in the various tables that need the user, you can always point it back to the appropriate table to get the current username, which is stored in only a single location. Any updates to the username occur only in that place, making the data more reliable.
A normalized database is advantageous when operations will be write-intensive or when ACID compliance is required. Some advantages include:
A normalized database is not as advantageous under conditions where an application is read-intensive. Here are some of the disadvantages of normalization:
In some cases, it isn’t as clear that one strategy should be used over the other. Obviously, some applications really need both normalized and non-normalized data to work as efficiently as possible.
In such cases, companies will often use more than one database: a relational data such as MySQL for ACID compliant and write-intensive operations and a NoSQL database such as MongoDB for read-intensive operations on data where duplication is not as big of an issue.
