Insertion anomaly: It occurs when you insert a data record as a row but the information is not available for all the columns, causing null values in a row.
Updation anomaly: It occurs when you update information in one row of a table, causing the previous information to be deleted, as there is no other copy of that data.
Deletion anomaly: It occurs when deletion of one row to remove data from some columns causes the data in other columns to be deleted as well. This occurs when data about multiple entities is stored in the same table. If information about one entity is deleted, then the information about another entity in the same row gets deleted.