What is the database normalization?
Database normalization is used in the database management system (DBMS), specifically with relational databases, to reduce redundant information and therefore minimize data anomalies. Anomalies may occur from information that is poorly grouped or redundant and can cause effects such as incorrect data insertion or deletion of the entire data group. By using the database normalization, we avoid these anomalies and the memory is usually released so that the database can work more efficiently. Normalization functions should be used regularly, about once a week to keep the database fresh and without unexpected problems.
No one makes a relational database to have excess data, but it usually happens despite the best efforts of the database designer. For example, with a database of employees, the employee can be listed on several tables. When redundancy occurs on a large scale, anomalies arise. Database administrators usually cannot capture all redundant data so the database normalization is notA better way to fix this problem.
The first task of the database normalization is to delete or move the repeat of information. If the information is unnecessary, they will be removed from the database. For the data needed in other tables, normalization is trying to create better relational tables. The normalization function divides large tables, corrects and strengthens the relations between data and isolate information to facilitate data editing in the database. By deducting recurring data, the memory is usually released, allowing the database more smoother and faster.
Anomalies occur when rejecting or forgetting to normalize the database and can cause information to be unnecessary. The update anomalies are when someone updates data, but instead of changing targeted data, the database creates a new record that is high redundant. With advertising anomaly, a record is added to the database, but nothing can be added under the new record. Dental anomoLie accidentally removes the record. This is just a few common anomalies that occur if the database is not normalized.
There is no fixed standard that should use the normalization function to ensure the efficiency of the database. Normalizing the database planning approximately once a week is usually the best, as it keeps all the new information added throughout the week after experiencing anomalies. Smaller databases can probably be normalized once a month and very large databases should be performed twice a week, as higher amounts of data cause a higher chance of anomalies. However, there is no standard, so the database manager usually chooses a plan that he thinks is the best for the database.