cs614 assignment no.3 fall 2019 2020

cs614 assignment no.3 fall 2019 2020
Assignment No. 03 Semester: Fall 2019CS614: Data Warehousing |
Total Marks: 15
Due Date: 27-Jan-2020 |
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Objective: The objective of this assignment is to enhance the learning capabilities of the students about:
Instructions: Please read the following instructions carefully before submitting assignment: You need to use MS word document to prepare and submit the assignment on VU-LMS. It should be clear that your assignment will not get any credit if:
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Question
HyperMart is an online shopping store currently acquiring a large number of customers.
Normalized table structures for the shopping store are given below:
Order Table
M Order details Table
Table Information
Task
For the given relations you are required to calculate the following costs in terms of I/O operations and find out which joining technique is better for given scenario. Tasks you are required to perform are as under;
Ans: Ratio between order and order detail table is 1:12 As 10,000 orders are there , 12×10,000=120,000 records will be in order detail table. Cost of sort merge=M log M+N log N+(M+N) M=10,000 N=120,000 =10,000 log (10,000)+120,000 log(120,000)+(10,000+120,000) =10,000(4)+120,000(5.07918124605)+(10,000+120,000) =40,000+60950.17495+130,000 =779,501.7495
Ans: In matching phase cost=M+N I/Os =10,000+120,000 =130,000 Cost of hash join=260,000+130,000 =390,000 I/Os
Ans: For the give scenario hash joining technique is better as its cost is about 390,000 I/Os While the cost of merge sort is about 779,501.7495
Best of Luck! |
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