In computing, a snowflake schema is a logical arrangement of tables in a multidimensional database such that the entity relationship diagram resembles a snowflake in shape. The snowflake schema is represented by centralized fact tables which are connected to multiple dimensions.
The snowflake schema is similar to the star schema. However, in the snowflake schema, dimensions are normalized into multiple related tables, whereas the star schema's dimensions are normalized with each dimension represented by a single table. A complex snowflake shape emerges when the dimensions of a snowflake schema are elaborate, having multiple levels of relationships, and the child tables have multiple parent tables ("forks in the road"). The "snowflaking" effect only affects the dimension tables and NOT the fact tables.
Other articles related to "snowflake schema, schema":
... 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 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 ...