In data warehouse and data marts we maintain timestamp columns like “Last_Modified_Date or Created_Date” to track the exact date and time when the records were updated or inserted.These columns are called Audit Columns. But audit columns won’t track the deletion of columns. Last modified date stores the timestamp for record when it was modified for the last time and Created date will store the timestamp for the date on which the record was created, mostly we give it as SYSDATE
After we load the data for a particular day we can easily identify these newly loaded records by using audit columns. Whenever a record is inserted or deleted it makes a fresh timestamp entry through the Audit columns. So make sure that you include the Audit columns.