# CS614 Assignment No.2 Solution and Discussion

• Assignment No. 02  Semester: Spring 2019
CS614: Data Warehousing
Total Marks: 10 Due Date: 30-May-2019

Objective:
The objective of this assignment is to enhance the learning capabilities of the students about:
• De-Normalization
• Pre-Joining
• Storage Issues of Pre-joining

Instructions:
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:

♣ The assignment is submitted after due date.
♣ The assignment is not in the required format (.doc or docx)
♣ The submitted assignment does not open or file is corrupt.
♣ Assignment is copied(partial or full) from any source (websites, forums, students, etc)

Assignment

Question

HyperMart is an online shopping store currently acquiring a large number of customers. To manage some performance issues this online store requires to de-normalize its database for order and Order detail tables.
Normalized table structures are given below: Table Information

• Assume 1:12 record count ratio between Order master and Order detail for online store’s database
• Assume 10 million orders (120 million records in order detail).
• Assume 10 byte Order_ID.
• Assume 30 byte header for master and 60 byte header for detail tables.

You are required to perform the following tasks:

1. De-normalize the given tables using Pre-joining technique
2. Calculate the total space used with normalization
3. Calculate the total space used after de-normalization

Best of Luck!

• CS614 Assignment Solution

DENORMALIZED Table

1. DE normalization using pre-joining

In pre-joining all columns are moved from the master table into the detail table Detail table
2) Calculate the total space used with normalization

SOL:

Total space with normalization
= (H.S of master table * records in master table) + (H.S of detail table * records in detail table)
= (30 * 10) + (60 * 120)
= 300 + 7200
= 7.5 GB

¥ Calculate the total space used after de-normalization
Total space after de-normalization
= (H.S of detail table + H.S of master table – common join path (orde_id)) * (records in detail table)
= (60 + 30 - 10) * 120
= 80 * 120
=9600
9.6 GB

CS614-Assignment-Solution(72G6dF).docx  | |