Galaxy Schema

Essentially, Galaxy schema can be derived as a collection of star schemas interlinked and completely normalized to avoid redundancy and inaccuracy of data. It is also called Fact Constellation Schema.

Let's combine the above two Star Schemas.

Advantages

• Minimum or no redundancy as a result of Normalization.
• This is a flexible Schema, considering the complexity of the system.

Disadvantages

• Working on this schema is tedious, as Schema and database systems' complexity makes it more intricate.
• Data retrieval is done with multi-level joins combined with conditional expressions.
• The number of levels of normalization is expected, depending on the depth of the given database.