You can customize a data access class (DAC) in either of the following ways (see the diagram
below):
By altering the attributes of existing fields. You can use an altered field just as you
would any other existing field.
By declaring new (custom) fields.
Figure 1. Analyzing the content of the merged DAC instance in the cache object
Every custom field is declared within the code of a DAC extension; therefore, at run time,
the custom field is accessible only through the DAC extension instance of the cache
object.
