CS145 Assignment #3
Due Wednesday, October 20, 1999
Step 3 of Your PDA (Personal Database Application)
Note1: see Recording
Your Session in the on-line Getting Started With Oracle
document for a guide to preparing output to hand in with your assignment.
It will be useful for this and subsequent PDA parts.
Note2: Oracle is not being backed up. You need to save anything you need
long-term in the leland file system.
Write an SQL database schema for your PDA, using the CREATE
TABLE commands described in the handout
Getting Started With Oracle.
Pick suitable datatypes for each attribute.
Page 286 of the text gives you the principal options regarding types.
Hand in a printout of the commands you use to create your database
schema (it is a good idea to keep this file for the balance of the
Show the response of sqlplus to a request to describe each of your
For example, to see the schema for relation Foo type
Execute five INSERT commands to insert tuples into one of
Show the response of sqlplus and the relation that results when
you issue a SELECT * command.
Again, the information on how to do this step is in
Getting Started With Oracle.
Develop a substantial amount of data for your database and load it into
your relations using the SQL load command. See
The Oracle Bulk Loader for
information on how to bulk-load data.
To create the data,
write a program in any programming language you like that
creates large files of records in a format acceptable to the Oracle bulk
then load the data into your PDA relations. If you are using real
data for your PDA, your program will need to transform the data into
files of records conforming to your PDA schema. The rest of you will
write a program to fabricate data: your program will generate
either random or nonrandom (e.g., sequential) records conforming to
your schema. Note that it is both fine and expected for your data
values--strings especially--to be meaningless gibberish. The point
of generating large amounts of data is so that you can experiment with
a database of realistic size, rather than the small ``toy'' databases
often used in classes. The data you generate and load should be on
the order of:
- At least two relations with thousands of tuples
- At least one additional relation with hundreds of tuples
If the semantics of your application includes relations that are
expected to be relatively small (e.g., schools within a university),
it is fine to use some small relations, but please ensure that you
have relations of the sizes prescribed above as well. When writing a
program to fabricate data, there are two important points to keep in
- Although you have not (yet) declared keys in your
relations, in many cases you probably know that an attribute or set of
attributes in a relation will serve as a key. If so, be sure not to
generate duplicate values for these attributes.
- Your PDA almost certainly includes relations that are
expected to join with each other. For example, you may have a
Student relation with attribute courseNo that's expected to
join with attribute number in relation Course. In
generating data, be sure to generate values that actually do
join--otherwise all of your interesting queries will have empty
results! One way to guarantee joinability
is to generate the values in one
relation, then use the generated values in one relation to select
joining values for the other relation.
For example, you could generate course
numbers first (either sequentially or randomly), then use these
numbers to fill in the courseNo values in the student
Turn in your program code for generating or transforming data, a small
sample of the records generated for each relation (5 or so records per
relation), and a script showing the loading of your data into Oracle.
Consider a relation R(a,b,c,d,e) with FD's:
Find all the (minimal) keys for R.
How many superkeys are there (including the keys)?
Explain your reasoning for partial credit.
Which of the given FD's violates BCNF?
For one such FD, perform a decomposition of R.
For each of your decomposed relations from (c), find the projected
This problem is based on the relations:
Customers(custID, name, email, shipAddr)
Orders(orderID, custID, itemID, date, status)
Write, in both relational algebra and in SQL the following
For relational algebra, you may write a sequence of steps with named
temporary relations if you like.
Find the email of the customer(s) with name ``Laura Lee.''
Find the names of the customers whose orders were placed on Jan. 1,
2000, and whose order status is ``lost.''
Find the descriptions of the items ordered by ``Laura Lee.''
Find the names of the customers who have two or more orders with status