Computer Science 255
Review for Third hour exam
(to be given Monday, Nov. 24)
Usual caveats apply
Reading - Remaining chapters in the textbook
including additional material on dataflow diagramming,
entity-relationship diagramming, and moving from an E-R diagram
to an indexed file design. Also the paper by Barry Dwyer.
Topics
- Sorting: Be comfortable with the basic
ideas of external sorting. Be able to say what happens during
a distribution-merge sort.
- Variable Length Records
- (Basic) Control Scripts
- MFU: Understand the ñbalanced lineî algorithm
(DwyerÍs algorithm) for sequential master file update. Be able to
write portions of a sequential MFU program.
- Data Flow Diagrams: Be able to construct a
simple DFD.
- Indexed files: be able to
- Specify an indexed file (SELECT statement)
- Read an indexed file sequentially by an indexed field
- Read an indexed file directly by an indexed field
- Do a group access on an indexed file
- Entity-relationship diagrams:
- Be able to draw a simple E-R diagram
- Be able to take a simple E-R diagram and
construct a file schema for indexed files, indicating keys and
foreign keys, and where indexes might be placed.
Material on the relational algebra, B-trees, and relative files
will appear on the final exam, but not on this third hour exam.
Return to class
home page