You can call a GetEstimatedSize event handler defined on another metaclass to use this size in your calculation. For example, you may define GetEstimatedSize on the Table metaclass, and make a call to GetEstimatedSize defined on the Column and Index metaclasses to use these sizes to calculate the total size of the table.
GetEstimatedSize(message[,true|false])
GetEstimatedSize(message, false)The use of the false parameter (which is the default, but which is shown here for clarity) means that we call the GetEstimatedSize event handler on the other metaclass, and use the default mechanism only if the event handler is not available.
GetEstimatedSize(message, true)