John

• Mar 13th, 2005

 

The snowflake schema is a schema in which the fact table is indirectly linked to a number of dimension tables. The dimension tables are normalized to remove redundant data and partitioned into a number of dimension tables for ease of maintenance. An example of the snowflake schema is the splitting of the Product dimension into the product_category dimension and product_manufacturer dimension..

Guest

• Mar 13th, 2005

 

The star schema is created when all the dimension tables directly link to the fact table. Since the graphical representation resembles a star it is called a star schema. It must be noted that the foreign keys in the fact table link to the primary key of the dimension table. This sample provides the star schema for a sales_ fact for the year 1998. The dimensions created are Store, Customer, Product_class and time_by_day. The Product table links to the product_class table through the primary key and indirectly to the fact table. The fact table contains foreign keys that link to the dimension tables.

Vamseedhar

• Mar 13th, 2005

 

Read more on this here .... http://www.exforsys.com/content/view/1301/332/This tutorial covers Designing the Dimensional Model, Dimensional Model schemas like Star Schema, Snowflake Schema, Optimizing star schema and Design of the Relational Database, OLAP Cubes and Data mining tools, Security considerations, metadata and backup and recovery plans

sudhakar

• May 9th, 2005

 

star schema uses denormalized dimension tables,but in case of snowflake schema it uses normalized dimensions to avoid redundancy...

sithusithu

 Profile Answers by sithusithu 

• Jan 9th, 2006

 

Star schema

A single fact table with N number of Dimension

 

Snowflake schema

Any dimensions with extended dimensions are know as snowflake schema

 

Cheers,

Sithu

Guest

• Feb 13th, 2006

 

Star Schema                                   snowflake schema
-----------                                     ----------------
Star schema is normalised                 Denormalised.
Easy to use and understand              End users will gt confused.
Want little efforts for maintainance     Easy to maintain
Fast execution of queries                  More time for exec bcas of more joins

sk.rafee

 Profile Answers by sk.rafee 

• Apr 25th, 2006

 

star schema uses denormalized dimension tables,but in case of snowflake schema it uses normalized dimensions to avoid redundancy...