For example this is the converse of delete anomaly - we can't add a new course unless we have at least one student enrolled on the course. Insertion Anomaly - The nature of a database may be such that it is not possible to add a required piece of data unless another piece of unavailable data is also added.Īlso to know, what is an insertion anomaly?Īn Insert Anomaly occurs when certain attributes cannot be inserted into the database without the presence of other attributes. Subsequently, question is, what is a data anomaly? Anomalies are problems that can occur in poorly planned, un-normalised databases where all the data is stored in one table (a flat-file database). There are three types of Data Anomalies: Update Anomalies, Insertion Anomalies, and Deletion Anomalies. For example, each employee in a company has a department associated with them as well as the student group they participate in.
An update anomaly is a data inconsistency that results from data redundancy and a partial update. There are three types of anomalies: update, deletion and insertion anomalies.
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