For example in the above table the department assigned to Anushka is an error because it needs to be updated at two different place to maintain consistency.Ĭ)ĝeletion Anomaly: Deletion anomaly occurs where deletion some data is deleted because of deletion of some other data. In other words a correct update of database needs other actions such as addition, deletion or both. So in the case mentioned above removing such type of problems requires splitting of the database which is done by normalization.ī) Update anomaly: This occurs in case of data redundancy and partial update. For example suppose any professor is hired but not immediately assigned any course group or any department may not get his/her place in such type of flat database mentioned above, if null entries are not allowed in the database. There are three types of database anomalies:Ī) Insertion anomaly: An insertion anomaly occurs when we are not able to insert certain attribute in the database without the presence of other attribute. Generally this is removed by the process of normalization which is performed by splitting/joining of tables.

Database anomaly is normally the flaw in databases which occurs because of poor planning and storing everything in a flat database.

What is anomaly in database