Computer-implemented methods, systems and products, the method comprising receiving, at a data server associated with a database, a command for data transfer between a client machine and the data server over a communications network, the data being stored in at least a data table comprising one or more columns; in response to receiving the command for data transfer, determining whether one or more columns of the data table are designated; identifying the one or more designated columns, such that data associated with the one or more designated columns is either considered or not considered for purpose of the data transfer; and executing the command to transfer the data in the database according to the designated columns.