Saint Louis University |
Computer Science 371
|
Dept. of Math & Computer Science |
Topic: Query Evaluation
Related Reading: Chapters 10 and 11, and lecture notes.
Due:
3:10pm, Friday 9 December 2005
(Note well the 3:10pm time)
For this assignment you may work with one other student if you wish. Please make sure you adhere to the policies on academic integrity in this regard.
Question B on our previous homework involved the design of a query to create a list of the names of all counties in state with abbrev='MO' such that there exists a feature in the county that has name 'Grand' and type 'Blvd'. We gave a specific query to solve this problem in our solutions.
You are to analyze the three evaluation plans which result from that precise query given in the solution set, when run on tiger1, tiger2, and tiger3. Your analysis should be done in a style similar to what we did for A and E in the lecture notes, giving a printout of the three textual evaluation plans together with an annotated diagram of the evaluation plan as a tree, for each.
Note: You may hand draw your diagrams if you wish. Please make sure they are clear and legible. Please also make sure that you give details as to how each relational operation is evaluated (e.g., the type of join algorithm used, when indices are used versus scans, when each condition it checked).
Exercise 11.6 of the text (page 426)
In answer the first part, please be explicit about pushing projections and selections as far as possible. For the second part, use analysis in similar fashion to that of Chapter 11.3.