CS
3050
Spring 2007
Study Guide for Quiz 3
The quiz will cover chapters 6 and 7. As part of your
review process, I recommend you study:
- Notes from class
- Reread book chapters
- Homework assignments
- Lab assignments
Chapter
6: Organizing Files for Performance
1. Know what data compression is and why we do it.
2. Know the data compression techniques and algorithms we went over in
class.
3. Understand how and why we reclaim space in files: statically using
record deletion and storage compaction; dynamically using the avail list for both fixed and
variable length records.
4. Be able to discuss and provide examples of both internal and
external fragmentation.
5. Be able to discuss and provide examples of placement strategies of
reclaiming space from variable length records that have been deleted.
6. Understand the issues that arise when we want to find a specific
record in a file quickly; the search algorithms that we discussed in
class and their performance.
7. Understand the keysort algorithm, why it is not ideal, and its
effect on pinned records.
Chapter
7: Indexing
1. Know the definition of and index and a simple index for
entry-sequenced files.
2. Know the operations required to create and maintain an indexed file.
3. Understand the consequences of our assumption that index files are
small enough to be loaded into memory.
4. Understand how secondary indexes work and the operations to maintain
them.
5. Understand how to retrieve information using a combination of
secondary keys.
6. Understand how and why secondary indexes can be improved with
inverted list.
7. Know why we might want to use selective indexes.
8. Understand binding policies in the context of a database system.