Understanding dimensional tables in Snowflake schema

In this blog post, we will dive into the concept of dimensional tables in the Snowflake schema. A Snowflake schema is a popular data modeling technique used in data warehousing. It organizes data into multiple normalized tables, connected through foreign keys, forming a structure resembling a snowflake.

Table of Contents

  1. Introduction to Snowflake schema
  2. What are dimensional tables?
  3. Advantages of using dimensional tables
  4. Example of a dimensional table in Snowflake schema
  5. Conclusion

Introduction to Snowflake schema

The Snowflake schema is an extension of the star schema and is widely used in data warehousing. It offers advantages such as improved data integrity and query performance by normalizing dimension tables.

What are dimensional tables?

Dimensional tables in a Snowflake schema are tables that store attributes or descriptive data related to the business entities. They provide context and details about the data stored in fact tables.

Advantages of using dimensional tables

There are several advantages to using dimensional tables in a Snowflake schema:

  1. Improved query performance: Dimensional tables in Snowflake schema use smaller, normalized tables, which results in faster query execution.

  2. Easy to understand and navigate: The dimensional tables provide a clear structure and hierarchy, making it easier for users to navigate and understand the data.

  3. Enhanced data integrity: Since the dimension tables store descriptive attributes, it reduces data redundancy and improves data integrity.

Example of a dimensional table in Snowflake schema

Let’s consider an example of an e-commerce database. We can have a dimensional table called product_dimension, which contains attributes related to the products being sold. The table may include columns such as product_id, product_name, brand, category, and price.

CREATE TABLE product_dimension (
  product_id INT,
  product_name VARCHAR,
  brand VARCHAR,
  category VARCHAR,
  price DECIMAL
);

In this example, the product_dimension table contains descriptive attributes of products, which can be linked to a fact table that stores transactional data.

Conclusion

Dimensional tables play a crucial role in the Snowflake schema by providing context and descriptive details about the data stored in fact tables. They enhance query performance, data integrity, and the overall understandability of the data model.

By utilizing dimensional tables effectively, you can build a powerful data warehousing solution with Snowflake schema. Happy analyzing!