Introduction
When
we think about a Fact table in dimension model, it has some foreign
key, combining all foreign key make the Primary key and of course
Fact columns (Numeric in nature where we can Use Aggregate function).
Now what is Factless
Fact Table
The
name tells everything. It is a fact table without Fact columns.
Yes I am right the fact table contains foreign key, Combining Foreign key makes Primary Key and NO FACT Columns.
Yes I am right the fact table contains foreign key, Combining Foreign key makes Primary Key and NO FACT Columns.
Use of FactLess Fact
Table
So
you can ask me what the use of such kind of Fact table where there is
No Fact Exists. Yes, it is also required in data model but depends on
situation to situation.
Now
I am going to make a situation where we can understand the use of
Fact Less Fact table.
Example:
In
the bellow figure I am going to lay down a data model.
If
we provide such query
SELECT
customer_name,
COUNT
(ContactType)as
[CONTACT COUNT]
FROM
Fact_Conatct
JOIN
...
Here
fact table take a records every time when the Customer make any
contact, so counting the “ConatctType” key we can understand the
fact easily without storing it.
Hope
you like it.
Posted
by: MR. JOYDEEP DAS
