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What Snow Flake Schema

Answered by Girinath.S.V.S on 2005-03-17 06:40:48: Snowflake schemas normalize dimensions to eliminate redundancy. That is, the dimension data has been grouped into multiple tables instead of one large table. For example, a product dimension table in a star schema might be normalized into a products table, a product_category table, and a product_manufacturer table in a snowflake schema. While this saves space, it increases the number of dimension tables and requires more foreign key joins. The result is more complex queries and reduced query performance

Total Answers and Comments: 8

Last Update: July 22, 2008

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Submitted by: sithusithu

Star schema

A single fact table with N number of Dimension

Snowflake schema

Any dimensions with extended dimensions are know as snowflake schema

Multiple Star (galaxy)

If the schema has more than one fact table then the schema is said to be Multiple star

Cheers,

Sithu

Above answer was rated as good by the following members:
ankeshjain, phdsong

March 17, 2005 06:40:48

Girinath.S.V.S

RE: What Snow Flake Schema

Snowflake schemas normalize dimensions to eliminate redundancy. That is, the dimension data has been grouped into multiple tables instead of one large table. For example, a product dimension table in a star schema might be normalized into a products table, a product_category table, and a product_manufacturer table in a snowflake schema. While this saves space, it increases the number of dimension tables and requires more foreign key joins. The result is more complex queries and reduced query performance

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October 04, 2005 01:22:29

senkumar79

Member Since: October 2005 Contribution: 17

RE: What Snow Flake Schema

A normalised form of star schema is called snow flake schema.

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October 10, 2005 23:06:46

Ramky18

Member Since: October 2005 Contribution: 2

RE: What Snow Flake Schema

The snowflake schema is an extension of the star schema, where each point of the star explodes into more points. The main advantage of the snowflake schema is the improvement in query performance due to minimized disk storage requirements and joining smaller lookup tables. The main disadvantage of the snowflake schema is the additional maintenance efforts needed due to the increase number of lookup tables.

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December 14, 2005 08:45:04

Siva K

RE: What Snow Flake Schema

Some people are considering as Normalized star schema, but it is partially normalized star schema. By partially normalizing it we may save some disk space.

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January 09, 2006 02:55:52

sithusithu

Member Since: December 2005 Contribution: 161

RE: What Snow Flake Schema

Star schema

A single fact table with N number of Dimension

Snowflake schema

Any dimensions with extended dimensions are know as snowflake schema

Multiple Star (galaxy)

If the schema has more than one fact table then the schema is said to be Multiple star

Cheers,

Sithu

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July 19, 2007 07:57:45

bhawesh

RE: What Snow Flake Schema

The snowflakeÂ schemaÂ is a method of storing data which are multidimensional in nature (i.e. which can be analysed by any or all of a number of independent factors) in aÂ RDBMS.

ItÂ is a variation of star schema.

Snowflake schema consist of one Fact table connected toÂ multiple dimension tables.

All the tables that describes dimensions of Snowflake schema must be in 3 NF.

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September 06, 2007 07:06:36

jyotsna

RE: What Snow Flake Schema

Any schema with extended dimensions(ie., dimesion with one or more extensions) is known as snowflake schema

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July 22, 2008 07:51:26

harshadapj

Member Since: July 2008 Contribution: 2

RE: What Snow Flake Schema

Closely related to the star schema, the snowflake schema is represented by centralized fact tables which are connected to multiple dimensions

In the snowflake schema, however, dimensions are normalized into multiple related tables whereas the star schema's dimensions are denormalized with each dimension being represented by a single table.

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