1. In a data visualization system including a data visualization configuration system, a method of creating one or more modifiable database interface objects that are used to represent data values for visualization in a graphical representation, the method comprising the steps of: creating one or more modifiable database interface objects that are used to access data values for visualization of the data values in the graphical representation; detecting an instruction to create a new modifiable database interface object from a list of parent modifiable database interface objects, creating a proxy modifiable database interface object as the new modifiable database interface object for each parent modifiable database interface object associated with the instruction; enabling the proxy modifiable database interface object to be available for modification, where the proxy modifiable database interface object refers to its associated parent modifiable database interface object; and utilizing a least one proxy modifiable database interface object to obtain data, wherein the data obtained is used to form at least part of the graphical representation of the data in the data visualization system.