What is the difference between data dependency and structural dependency?

• Structural dependence

-Access to a file depends on its structure i.e. adding customer date-of-birth field to customer file require the five steps described in slide 29. the reason for this is that the file structure is coded within the program

• Data dependence

-Changes in database structure affect program's ability to access data i.e. changing field from integer to decimal required changes in all the files. the reason for this is that the file data characteristics are coded within the program.