list schemes used in implementaiton of Dimensional data store?

Dimensional data store(DDS) can be implemented physically in the form of several different
schemas.

Some examples of dimensional data store schemas are a

star schema
a snowflake schema,
and a galaxy schema.

In a star schema, a dimension does not have a subtable (a subdimension).

In a snowflake schema, a dimension can have a subdimension. The purpose of having a subdimension is to minimize redundant data.

A galaxy schema is also known as a fact constellation schema. In a galaxy schema, you have two or more related fact tables surrounded by common dimensions