Database Languages
eXercise #11 -
Part B
Table Design -
By Error and Trial
PART2: Some Extra
SOCK Information
Firstly, identify
all of the ASSUMPTIONS you have made about the data you have already
accommodated in your table system.
What problems have
you encountered, are you happy with your solutions to them?
Have you placed
any unreasonable restrictions on the information contained, have you
had to leave any information out? Have you included any redundancy (i.e.
information that could easily be derived, and therefore does not need
to be stored)?
Given that you have
decided to use your table system read the following information carefully:
The factory,
as previously described manufactures more than socks. The BVD company
manufactures a full range of male and female undergarments (including
underpants, singlets, bras, girdles, stockings, pantyhose etc.) that
are made of similar blends (but not wool) as are the socks (eg. cotton,
nylon, poly-cotton) as well as silk, have a range of sizes to suit any
body and sex, come in many colours, and, like the socks are manufactured
in batches.
What modification
to your table structure will you need to make to allow for the extra
information described above? How will your system now refer to a garment
of clothing (ie what unique fields are to be used to differentiate a
particular type of sock, for example, from a pair of orthapaedic boxer
shorts) ?
Suppose
the owner of the factory also needs to keep track of what products (quantities,
sizes, colors and full type description) are sold to which Retailer.
This is because, regrettably, the quality control at the factory is
not what it used to be. For example, just last year, one of BVD's firm
control bras (due to the orientation of the underwires in conjunction
with the polarity of the metal clasps at the back) caused an electrical
interferance which allowed the wearer to receive FM transmission and
the entire batch had to be RECALLED. (later they were resold - at a
huge profit, to a Japanese retailer who were excited by the prospect
of innovative electronic underwear).
What modification
to your table structure is necessary to accommodate this new twist in
the continuing story ?
What is moral to
this story (ie. why did we embark on this exercise)?
