Question

The data structures that we use in applications often contain a great
deal of information of various types, and certian pieces of
information may be belong to multiple independent data structures. For
example, a file of personnel data may contain records with names,
addresses, and various other pieces of information about employees;
and each record may need to belong to one data structure for searching
for particular employees, to another data structure for answering
statistical queries, and so forth.

Despite this diverstiy and complexity, a large class of computing
applications involve generic manipulation of data objects, and need
access to the information associated with them for a limited number of
specific reasons. Many of the manipulations that are required are a
natural outgrowth of basic computational procedures, so they are
needed in broad variety of applications.

Above text is described in context of abstract data types by Robert Sedwick in Algorithms in C++.

My questions is what does author mean by first paragraph in above text?

Answer 1

It would help if one knew what the conclusion of all this is, but from what I gather:

Employee record:

Name Address Phone-Number      Salary Bank-Account      Department Superior

As you can see, the employee database has information for each employee that by itself is “subdivided” into chunks of more-or-less independent pieces: the contact information for an employee has little or nothing to do with the department he works in, or the salary he gets.

EDIT: As such, depending on what kind of stuff needs to be done, different parts of this larger record need to be looked at, possibly in different fashion. If you want to know how much salary you’re paying in total you’ll need to do different things than for looking up the phone number of an employee.