A HOLD file is valuable when you want to do the following:
            
               - Extract fields from
                  a large data source for faster and more efficient retrieval in subsequent
                  requests. This reduces processing time, enabling you to create reports and
                  charts rapidly against a smaller, more specialized data set. This
                  improves efficiency while giving you the flexibility that you need
                  when working with smaller subsets of your data.
               
 
               - Store virtual field
                  values or summary values calculated in one request for further processing
                  in another request. This allows you to reuse calculated values,
                  decreasing the effort required to recreate certain scenarios.