Schema defines the type of structure that is used by the database to hold on some data that can be related or can be different.

There are three types of schema that exists in the database as follows:

BUS schema: This is the schema that is composed of the master file that is totally confirmed with the dimension and with standardized definition including the facts.

Star schema: This is the schema that defines the organization type of the tables and it is used to retrieve the result from the database quickly in a controlled environment.

Snow flake schema: This schema is used to show the primary dimension table, that includes one or more dimensions that can be joined. Primary dimension table only allows the joining of the fact table.