Information

• The midterm exam will be held on Wednesday May 3 from 11:00 AM until 12:15 PM in the Gates Computer Science Building Room B01 (the Hewlett-Packard Auditorium) on the Stanford campus. All students, including SITN students, are expected to attend the exam on-campus. There will be no early or makeup exams.

• The exam will be closed book. However, each student may bring up to three pages of prepared notes. That's six total sides of writing on 8-1/2"x11" paper.

• Sample exams from Prof. Widom's Spring '98 offering of CS145 are linked to the course home page.

• A sample solution for Written Assignment #3 will be linked to the course home page no later than midnight on Monday May 1.

• SITN Students: Please be sure to bring a routing slip with you to the exam. If you do not bring a routing slip, we will not be able to send your graded exam back by courier.

Review Session

Material Covered

• All lectures through Wednesday April 26

• Textbook readings: Chapters 1, 2.2-2.3, 2.4.3-2.4.4, 2.5 except 2.5.2, 2.6, 3.1, 3.3, 3.4.2, 3.4.4, 3.5-3.8, 4.1, 4.6.1-4.6.6, 5.1-5.7, 5.9, 7.1-7.4

• Written Assignments #1-3

• Project Parts 1-4

Since the material on transactions, authorization, and programming with SQL (covered in class and in the readings) has not yet been exercised in an assignment, any questions regarding this material on the exam will be straightforward.

What follows is an outline of the material we've covered so far. All of this material is fair game for the midterm exam.

1. Basic motivation and database terminology

2. Entity-relationship model and E/R diagrams
   • Entity sets, relationship sets, attributes, keys, roles
   • Multiplicity of relationship sets (one-to-one, one-to-many, etc.)
   • Weak entity sets
   • Subclasses ("isa" relationships)

3. Relational model
   • Relations (tables), attributes (columns), tuples (rows)
   • Schema versus instance
   • Keys, null values
   • Translating E/R designs to relations

4. Relational database design
   • Functional dependencies (FD's): motivation, definitions, rules
   • Closure of attribute set with respect to FD's
   • Design flaws: redundancy, update & deletion anomalies
   • Boyce-Codd Normal Form (BCNF): motivation, definition, decomposition algorithm
   • Multivalued dependencies (MVDs): motivation, definitions, rules
   • Fourth Normal Form (4NF): motivation, definition, decomposition algorithm

5. Relational algebra
   • Basic operators: select, project, Cartesian product, union, difference, rename
   • Abbreviations: natural join, theta join, intersection
   • Bag relational algebra

6. SQL
   • Data definition: create table, drop table
   • Data manipulation: select command
   • Subqueries, aggregates, duplicates, null values, join operations
   • Data modification: insert, delete, update

7. Indexes
   • Properties and uses of indexes
   • Creating indexes in SQL

8. Transactions, Authorization, Programming with SQL: cursory coverage only