DATABASES AND THE INTERNET - Fundamentals of Database Management Systems - page 381

Bookstore and
Bookstore Chain
Databases

Publisher
Databases

XML

F IGURE 14.10
XML as an independent layer of data
definition

data in its databases. Again, consider Good Reading Bookstores, but broaden the
view and realize that there are many bookstores and bookstore chains, and many
publishers and book wholesalers. Assume that every one of these companies agrees
to use a single standard XML description of books. Further, each company will
arrange to have software convert their stored book data to the standard XML format.
Then, they can all freely exchange book data with one another, Figure 14.10.
For example, if Good Reading has to order books from Publisher A, its software
converts the book data in its database needed for the order to the XML standard.
When Publisher A receives Good Reading's order in the XML standard, its software
converts the data from the XML standard to its own format and go on to process the
order. And, of course, this works in both directions. So, as long as Good Reading
can convert its data to the XML standard, it can assume that every publisher it deals
with can go on to convert the XML standard data to that publisher's data format,
and vice versa from the publishers to the bookstores.

SUMMARY

The Internet and its associated application, electronic commerce, have greatly
increased the activity of access to databases. This has brought up several issues, one
of which is modes of connectivity to the databases. Also, with the desire for access
to music, movies, and other media over the Internet, dealing with an expanded set
of data types has gained new importance. Access to databases over the Internet has