Editing Snowflake schema (section)

== Examples ==
[[Image:Snowflake-schema-example.png|300px|thumb|right|Snowflake schema used by example query.]]

The example schema shown to the right is a snowflaked version of the star schema example provided in the [[star schema]] article.

The following example query is the snowflake schema equivalent of the star schema example code which returns the total number of television units sold by brand and by country for 1997. Notice that the snowflake schema query requires many more joins than the star schema version in order to fulfill even a simple query. The benefit of using the snowflake schema in this example is that the storage requirements are lower since the snowflake schema eliminates many duplicate values from the dimensions themselves.
<syntaxhighlight lang=sql>
SELECT
	B.Brand,
	G.Country,
	SUM(F.Units_Sold)
FROM Fact_Sales F
INNER JOIN Dim_Date D             ON F.Date_Id = D.Id
INNER JOIN Dim_Store S            ON F.Store_Id = S.Id
INNER JOIN Dim_Geography G        ON S.Geography_Id = G.Id
INNER JOIN Dim_Product P          ON F.Product_Id = P.Id
INNER JOIN Dim_Brand B            ON P.Brand_Id = B.Id
INNER JOIN Dim_Product_Category C ON P.Product_Category_Id = C.Id
WHERE
	D.Year = 1997 AND
	C.Product_Category = 'tv'
GROUP BY
	B.Brand,
	G.Country
</syntaxhighlight>