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Question:  Dimension Table Vs Fact Table

Answer: What is the main difference in the logic when you create a mapping for a dimension table with that of a fact table in Informatica.


July 07, 2008 02:16:41 #2
 dwhlabs   Member Since: July 2008    Total Comments: 1 

RE: Dimension Table Vs Fact Table
 
Dimension Table features

1. It provides the context /descriptive information for a fact table measurements.
2. Provides entry points to data.
3. Structure of Dimension - Surrogate key , one or more other fields that compose the natural key (nk) and set of Attributes.

4. Size of Dimension Table is smaller than Fact Table.

5. In a schema more number of dimensions are presented than Fact Table.

6. Surrogate Key is used to prevent the primary key (pk) violation(store historical data).

7. Values of fields are in numeric and text representation.

Fact Table features

1. It provides measurement of an enterprise.

2. Measurement is the amount determined by observation.

3. Structure of Fact Table - foreign key (fk), Degenerated Dimension and Measurements.

4. Size of Fact Table is larger than Dimension Table.

5. In a schema less number of Fact Tables observed compared to Dimension Tables.

6. Compose of Degenerate Dimension fields act as Primary Key.

7. Values of the fields always in numeric or integer form.

 

     

 

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