Last year we had a production issue where one of our backup jobs was failing while inserting Orders aggregated from other systems into our SQL Server database. The reason was dreaded "Arithmetic overflow error converting IDENTITY to data type int" because the table was using IDENTITY feature of SQL Server to generate OrderId, and Identity has breached it a maximum value, which is around 2.1 billion, precisely 2,147,483,647. The error "Arithmetic overflow error converting IDENTITY to data type int" comes when the IDENTITY value is inserted into a column of data type int, but the value is out-of-range. For example, if the current value of Identity becomes more than 2,147,483,647, then you cannot store that into an int column because it's more than the maximum value of int in SQL Server. --- Java Interview questions and tutorials