CS614 Current Midterm Paper Fall 2013 File shared by saki78695 File 1

Today CS614 Midterm Term Paper

List down four basic tasks of data transformation? Data Transformation

ƒ  Basic tasks

1. ƒ  Selection
2. ƒ  Splitting/Joining
3. ƒ  Conversion
4. ƒ  Summarization
5. 5.      ƒ  Enrichment

Identify the given statements as correct and incorrect "The approach of TQM refers to the involvement of only 20% employee inthe continuous improvemnt process" and 2nd statement  was "orr's law says that data quality is a function of its use not its collection"

Solution: 1^st is wrong 2^nd is right

Stat 1.TQM  approach  is  advocating  the  involvement  of  all  employees  in  the  continuous

improvement process, the ultimate goal being the customer satisfaction.

Stat:Law #2:  “Data quality is a function of its use, not its collection!”

 Identify the given statement as correct and incorrect "in Molap the complexity cannot go beyound o(1) in any case" 2nd statement was "Drill down is a cube operation and its basic purpose is to select and project"

Solution: both are incorrect

1^st:The only time the time complexity goes beyond O(1) is when the cube size is so large that it can not fit in the main memory, in such a case a page or a block fault will occur.

2^nd:Drill down is cube operation BUT its basic purpose is “get more details”

 if dirty data in DWH is used by  the government for decision making then what would be  the effects?explain with exemple

Solution:

Serious Problems due to dirty data

ƒ  Decisions  taken  at  government  level  using  wrong  data  resulting  in  undesirable results. 

•  In direct mail marketing sending letters to wrong addresses loss of money and bad

reputation.

Administration: The government analyses data collected by population census to decide

which  regions  of  the  country  require  further  investments  in  health,  education,  clean

drinking water, electricity etc. because of current and expected future trends. If the rate of

birth in one region has increased over the last couple of years, the existing health facilities

and  doctors  employed  might  not  be  sufficient  to  handle  the  number  of  current  and

expected patients. Thus, additional dispensaries or employment of doctors will be needed.

Inaccuracies  in  analyzed  data  can  lead  to  false  conclusions  and  misdirected  release  of

funds with catastrophic results for a poor country like Pakistan.

Supporting business processes: Erroneous data leads to unnecessary costs and probably

bad reputation when used to support business processes. Consider a company using a list

of consumer addresses and buying habits and preferences to advertise a new product by

direct mailing. Invalid addresses cause the letters to be returned as undeliverable. People

being duplicated in the mailing list account for multiple letters sent to the same person,

leading to unnecessary expenses and frustration. Inaccurate information about consumer

buying  habits  and  preferences  contaminate  and  falsify  the  target  group,  resulting  in

advertisement of products that do not correspond to consumer’s needs. Companies trading

such data face the possibility of an additional loss of reputation in case of erroneous data.

   identify the given statement as correct and incorrect"Transactional fact table always stores the complete records for the event that dont occur?

Solution:False Statement

Correct is:

Transactional fact tables don’t have records for events that don’t occur

ƒ  Example:  No records(rows) for products that were not sold.