Derived Tables

Derived tables, also known as materialized views, are a powerful tool in data analysis and reporting. They allow you to create virtual tables that are derived from one or more existing tables, and then use those virtual tables in queries and reports as if they were real tables.

Benefits of Using Derived Tables

There are many benefits to using derived tables, including:

• Improved performance: Derived tables can improve the performance of queries and reports by avoiding the need to join multiple tables. This is especially beneficial for complex queries that involve large amounts of data.
• Data reusability: Derived tables can be reused in multiple queries and reports, which saves time and effort. You can also create derived tables that are specific to a particular project or task, which makes it easier to manage and maintain your data.
• Data security: Derived tables can be used to restrict access to sensitive data. By creating a derived table that only includes the data that users need to see, you can help protect your data from unauthorized access.

How to Create Derived Tables

There are many different ways to create derived tables. The most common way is to use a SQL query. The following example shows how to create a derived table called sales_by_product that shows the total sales for each product:

CREATE TABLE sales_by_product AS
SELECT
  product_id,
  product_name,
  SUM(sales) AS total_sales
FROM
  sales
GROUP BY
  product_id,
  product_name;