What are the different types of Fatcs?
Explain with example only

Answers were Sorted based on User's Feedback

What are the different types of Fatcs? Explain with example only..

Answer / guest

(2)Semi Additive
(3)Non Additive

Is This Answer Correct ?    12 Yes 3 No

What are the different types of Fatcs? Explain with example only..

Answer / nasa

Facts are 3

-Semi Additive
-Non Additive

Additive:: A value which can sumd up at any dimension

Semi Additive:: A value which can sumd up at only some dimensions

Non Additive:: A value which can't sumd up at any dimension

Is This Answer Correct ?    4 Yes 0 No

What are the different types of Fatcs? Explain with example only..

Answer / hariharan v

There are four types of facts available in it.
1) Factless Fact
2) Coverage Fact
3) Incident Fact
4) Snapshot fact

Examples :
1) Factless fact:
Consider a school, where a single student may be taught by
many teachers and a single teacher may have many students.
To model this situation in dimensional model, one might
introduce a fact-less-fact table joining teacher and
student keys. Such a fact table will then be able to answer
queries like,
a. Who are the students taught by a specific teacher.
b. Which teacher teaches maximum students.
c. Which student has highest number of teachers.etc. etc.

2) Coverage fact:
A fact-less-fact table can only answer 'optimistic' queries
(positive query) but can not answer a negative query. Again
consider the illustration in the above example. A fact-less
fact containing the keys of tutors and students can not
answer a query like below,
a. Which teacher did not teach any student?
b. Which student was not taught by any teacher?

Why not? Because fact-less fact table only stores the
positive scenarios (like student being taught by a tutor)
but if there is a student who is not being taught by a
teacher, then that student's key does not appear in this
table, thereby reducing the coverage of the table

Coverage fact table attempts to answer this - often by
adding an extra flag column. Flag = 0 indicates a negative
condition and flag = 1 indicates a positive condition. To
understand this better, let's consider a class where there
are 100 students and 5 teachers. So coverage fact table
will ideally store 100 X 5 = 500 records (all combinations)
and if a certain teacher is not teaching a certain student,
the corresponding flag for that record will be 0.

3) Incident Fact:
A fact table stores some kind of measurements. Usually
these measurements are stored (or captured) against a
specific time and these measurements vary with respect to
time. This is example of an Incident Fact.

4) Snapshot Fact:
Take the example of the incident fact. Now it may happen
that the business might not able to capture all of its
measures always for every point in time. The above
unavailable measurements can be kept empty (Null) or can be
filled up with the last available measurements. This is the
example of snapshot fact.

Is This Answer Correct ?    1 Yes 10 No

Post New Answer

More Data Warehouse General Interview Questions

How can we determine what records to extract?

0 Answers  

What is data analysis? Where it will be used?

0 Answers  

What according to you might be the future of data warehousing?

0 Answers  

What is a data warehousing?

0 Answers  

Can we have multiple application.cfm file in an application?

0 Answers  

Explain what are the vaious etl tools in the market?

0 Answers  

what is difference between Independent Data Mart Dependent Data Mart 1- 1- 2- 2- 3- 3- 4- 4-

4 Answers  

How many clustered indexes can you create for a table in dwh? In case of truncate and delete command what happens to table, which has unique id 347 what is hybrid slowly changing dimension?

0 Answers  

What is a cube in data warehousing concept?

0 Answers  

What are Non-additive facts?

0 Answers  

What is multi-dimensional analysis?

3 Answers   Satyam,

What are CUBES?

2 Answers