CS145 - Spring 2004
Introduction to Databases

Assigned Work

There are three types of assigned work in CS145:

Online exercises and labs using Gradiance, a system developed by Prof. Ullman and others
Challenge problems, whose solutions are to be typed up and turned in electronically
A significant multi-part programming project

The following table is a tentative schedule for the assigned work. Links to actual assignments will be added.

Assigned Date	Work	Due Date (11:59 PM)
Wed. April 7	Gradiance Exercises 1 -- two parts Challenge Problems 1	Tue. April 13
Wed. April 14	Gradiance SQL Labs -- two parts Challenge Problems 2	Tue. April 20
Fri. April 16	Project Part 0 (one week - trivial)	Thu. April 22
Wed. April 21	Gradiance XPath/XQuery Labs -- two parts Gradiance Exercises 3 -- three parts Challenge Problems 3	Thu. April 29 No lates
Fri. April 23	Project Part 1 (two weeks)	Thu. May 6
Fri. May 7	Project Part 2 (one week)	Thu. May 13
Wed. May 12	Gradiance Exercises 4 -- three parts Challenge Problems 4	Tue. May 18
Fri. May 14	Project Part 3 (two weeks)	Thu. May 27
Wed. May 26	Gradiance Exercises 5 -- three parts Challenge Problems 5	Tue. June 1

Please note the regrade and late policies below, as well as information about the Honor Code.
All work in CS145 - including the programming project - is completed individually, not as teams.
There is a separate page for project support materials.

Online Exercises and Labs

(20% of your final grade)
The purpose of the online exercises and labs is to ensure that you have learned the basic material in CS145. You will perform the exercises and labs using Gradiance, a unique system for generating different exercise sets on selected topics each time it's used, along with a lab component for automatically testing students' SQL, XPath, and XQuery solutions. Gradiance (formerly called Online Testing Center, or OTC) was launched in a 2002 offering of CS145, and is now a commercial product being used at several universities.

One of the best features of Gradiance is that you are permitted to test yourself on a particular topic as many times as you like. We strongly encourage you to continue testing on each topic until you complete the assignment with a 100% score at least once.

For each Gradiance exercise set or lab, your score is the highest score achieved as of 11:59 PM on the due date. There is no late policy for Gradiance work.

Challenge Problems

(5% of your final grade)
Challenge problems are generally more open-ended and more difficult than the exercises and labs in Gradiance. The challenge problems are designed to make you think more deeply about the topics covered. Some (but not all) of the problems are by design very challenging! We do not expect most students to completely solve every single challenge problem in the course. Grading of challenge problems is on a relatively coarse scale, and credit is given if you make a good attempt at a problem and are in the direction of the right solution.

There are typically 1-2 challenge problems accompanying each Gradiance assignment. We ask you to type up your solutions and submit them electronically. (Details are provided with the assignments, and students who strongly prefer to hand-write their solutions may scan them for submission.) The late policy for challenge problems is outlined below.

Programming Project: AuctionBase

(25% of your final grade)

Introduction

Your project is to build an online auction system called AuctionBase. At the back-end, AuctionBase manages all of its data in the Oracle database management system. At the front-end, AuctionBase provides a friendly Web interface to its users. AuctionBase is modeled roughly after the eBay online auction system. In fact, we will give you a considerable amount of real data downloaded from eBay (courtesy of the University of Wisconsin) to initially populate your AuctionBase system.

We will expect certain minimal functionality in each AuctionBase system - beyond that, the sky's the limit. Minimal functionality includes a variety of queries and browsing capabilities over the current items up for auction, the bids on those items, and the sellers and bidders. AuctionBase also must provide a means for entering bids, and for concluding auctions on individual items. Various integrity constraints must be monitored. Although AuctionBase uses the Oracle DBMS and therefore has transaction support, multi-user issues are not a focus of the project.

Web programming skills are not required for the AuctionBase project. We will provide skeleton Java servlets and HTML code for most aspects of the Web interface. Those students savvy in Web programming may rewrite or extend the interface as they please.

At the end of the course, there will be a "contest" in which we select a few of the best AuctionBase systems to be demonstrated in class and linked to the course home page. No extra credit is given, but winners will be invited to enjoy lunch at the Stanford Faculty Club with Prof. Widom, the TA's, and the other contest winners.

The scope of the AuctionBase project is such that it can easily be completed by each student in the class individually - partners or teams will not be used.

Programming and System Issues

To develop the project all students will use the Oracle relational database management system (Oracle 9.01 server, 8.1.7 clients) and the Unix operating system. You will try out Oracle's sqlplus interactive interface, its PL/SQL proprietary programming language, and several other features. For the Web front-end and interacting with Oracle, students are expected to use the Java programming language, Java Servlets, and JDBC. Help sessions will be provided.

There are many other ways to develop Web applications and interact with Oracle, e.g., using C++ and CGI, or using PHP. Students are welcome to use alternative languages and tools if they wish, and we have linked to support materials for some of them, however only Java and JDBC will be supported by the course staff, and the specifications for the project must be met regardless of the languages or tools used. The project also includes processing of XML files. We will provide XML parsers in Java and C++, but again students are welcome to use other tools or languages if they prefer.

Important note: Students using alternative languages and tools must be able to submit all of their code using the standard submission procedure. Furthermore, the TA's must be able to compile and run all submitted code on the leland machines without any additional packages or runtime support, and with no additional effort over that required for projects using the supported languages and tools.

Oracle and Java are available on the Sun Solaris workstations on the second floor of Sweet Hall, e.g., the saga, elaine, and myth machines. To open an account on these machines, type open at the login: prompt and follow the instructions. SCPD students can access the Sun workstations remotely. If you have access to an equivalent Oracle system (version 8 or higher, including PL/SQL and JDBC), you may use it instead of the Stanford system. However, we do expect you to use Oracle and not some other DBMS - not because we love Oracle, but because we can support only one DBMS, and we will be exploring some specific capabilities of this system. If you choose to use your own workstation and/or your own Oracle system, please be aware that we cannot make any exceptions for problems incurred by using your own computing facilities rather than those provided by Stanford.

We will assume that students are proficient already with Unix and with the the Java programming language.

Project Parts

The AuctionBase project proceeds in four parts. The schedule for assignment and completion of project parts is specified in the table at the top of this page.

Part 0: Trivial Oracle Warm-Up
You will log into Oracle and run a few commands using sqlplus. This part is trivial - it simply ensures that your Oracle account is functional and you know how to perform basic operations with Oracle.
Part 1: AuctionBase Schema and Data
You will be given a large volume of data downloaded from the eBay Web site and stored in XML files. You will examine the data and design a good (we hope) relational schema for it. You will then write a program or scripts to transform the data from its XML form into Oracle's load file format, conforming to your relational schema. You will create your schema in your own Oracle database and load the data.
Part 2: Oracle Features
This part of the project will expose you to some additional aspects of Oracle, using the AuctionBase data. You will experiment with indexes and views, write a small PL/SQL program, and implement some constraint-checking features using Oracle CHECK constraints and triggers. You will also add a "current time" feature to your AuctionBase database.
Part 3: AuctionBase Web Site
As a baseline, you will design an appropriate set of queries and updates for your AuctionBase system and create a simple Web interface for them. Ambitious students may migrate the simple front-end into a user-friendly Web interface that looks like a real auction site, and may exploit triggers and other Oracle features for additional functionality. Use your creativity. Several projects will be selected to be demonstrated on the last day in class (for glory, not grades).

Late Policy

All work in CS145 is either through Gradiance or submitted electronically.
11:59 PM on the due date is always the deadline.
Online exercises and labs: There is no late policy - the highest score achieved on Gradiance as of 11:59 PM on the due date is your score for that assignment.
Challenge problems and programming project: Submissions after the deadline but less than 24 hours late will be accepted but penalized 10%, and submissions more than 24 hours but less than 48 hours late will be penalized 30%. No submissions will be accepted more than 48 hours late.
Emergencies: Since emergencies do arise, each student is allowed a total of four unpenalized late days (four periods up to 24 hours each) for challenge problems together with programming work. (But note that no single assignment may be turned in more than two days late.) If you exceed this amount and are penalized for late work, we will automatically apply the four unpenalized late days to the work it benefits the most, i.e., to the work that is worth the most in calculating your final grade.

THIS LATE POLICY WILL BE STRICTLY ENFORCED.

Regrade Policy

Only challenge problems and programming work can be regraded. (If you find a significant technical error in Gradiance exercises or labs you'll receive extra credit!) Please send an email message to cs145@cs stating that you believe you deserve a regrade and explaining precisely why. Please do not ask for a regrade on a challenge problem until you have studied our sample solution. Include your name, leland username, and the number of the challenge problem or project part in question. The TA responsible for grading the work will contact you.

Honor Code

Under the Honor Code at Stanford, each of you is expected to solve Gradiance exercises and labs independently, and to submit your own original work for challenge problems and the programming project. On many occasions when working on assignments (but never exams!) it is useful to ask others - the instructor, the TA's, or other students - for hints, or to talk generally about aspects of the assignment. Such activity is both acceptable and encouraged, but you must indicate on all submitted challenge problems and programming work any assistance (human or otherwise) that you received. Any assistance received that is not given proper citation will be considered a violation of the Honor Code. In any event, you are responsible for understanding, performing or writing up, and being able to explain on your own, all Gradiance exercises, Gradiance lab queries, and other work that you submit. The course staff will pursue aggressively all suspected cases of Honor Code violations, and they will be handled through official University channels.

If you have any questions about this policy or about the degree to which we will pursue Honor Code violations, please discuss your concerns with the course staff immediately.