1.experiment
2 . Design multi-dimensional data models namely Star, Snowflake and Fact Constellation schemas forany one enterprise (ex. Banking, Insurance, Finance, Healthcare, manufacturing, Automobiles,sales etc).
What is Schema?
Schema is a logical description of the entire database.
Star Schema:
A star schema is the elementary form of a dimensional model, in which data are organized into facts and dimensions.
This dimension table contains the set of attributes.
The following diagram shows the sales data of a company with respect to the four dimensions, namely time, item, branch, and location.
There is a fact table at the center. It contains the keys to each of four dimensions.
Some dimension tables in the Snowflake schema are normalized.
The normalization splits up the data into additional tables.
Fact Constellation Schema:
A Fact constellation means two or more fact tables sharing one or more dimensions. It is also called Galaxy schema.
This schema defines two fact tables, sales, and shipping. Sales are treated along four dimensions, namely, time, item, branch, and location.
It is also possible to share dimension tables between fact tables. For example, time, item, and location dimension tables are shared between the sales and shipping fact table.
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