The following are common database schemas used in relational database management systems (RDBMS), including the Star Schema, from which the Snowflake Schema is derived:

1. Star Schema:
   • The foundational schema that involves a central fact table connected directly to several dimension tables.
   • Simpler structure with denormalized dimension tables.
   • Offers faster query performance due to fewer joins.
2. Snowflake Schema:
   • Derived from the Star Schema.
   • Normalizes dimensions into multiple related tables.
   • Reduces redundancy but can make queries more complex.
3. Galaxy Schema (Fact Constellation Schema):
   • Contains multiple fact tables that share dimension tables.
   • Used for more complex data warehouses with multiple data marts.
4. Hierarchical Schema:
   • Organizes data in a tree-like structure.
   • Used for databases that require a clear parent-child relationship, like organizational charts.
5. Network Schema:
   • Similar to the Hierarchical Schema but allows more complex relationships with many-to-many connections.
   • Often used for more complex, non-hierarchical relationships.
6. Flat Schema:
   • A single table or a simple structure without hierarchical relationships.
   • Typically used for small, simple databases.

These schemas are utilized based on the specific needs of the database structure, data integrity, and query complexity.