The snowflake schema consists of one fact
table that is connected to many dimension tables, which can be connected
to other dimension tables through a many-to-one relationship.
Tables in a snowflake schema are usually normalized to the third
normal form. Each dimension table represents exactly one level in
a hierarchy.
The following figure shows a snowflake schema with two dimensions,
each having three levels. A snowflake schema can have any number of
dimensions and each dimension can have any number of levels.
Figure 1. Snowflake schema with two dimensions and three levels each