**Title:** What is a Materialized View?
**SEO Keywords:** materialized views, data warehousing, SQL, database performance, query optimization

**Intro:**
When working with large datasets, querying and aggregating data can be a time-consuming process. One technique to improve query performance is by using materialized views. In this post, we'll explore what materialized views are, how they work, and their benefits.

**Main Blog Content:**

Materialized views are pre-computed results of a database query that are stored in a physical table. Unlike regular views, which are virtual tables based on the result-set of a SELECT statement, materialized views store the actual data, making them faster to access.

Imagine you have an e-commerce platform and want to frequently calculate the top-selling products for each category. You can create a materialized view that pre-computes this information periodically, say once a day. When a user wants to know the top-selling products, your application can simply query the materialized view instead of running a complex query on the original data.

**How Materialized Views Work:**

When you create a materialized view, the database engine performs the following steps:

1. **Query Execution**: The database executes the query that defines the materialized view.
2. **Data Retrieval**: The results are stored in a physical table.
3. **Cache Invalidation**: Any changes to the underlying data trigger cache invalidation.

**Benefits of Materialized Views:**

1. **Improved Query Performance**: Materialized views pre-compute complex queries, reducing query execution time and improving performance.
2. **Reduced Load on Original Data**: By storing results in a separate table, you reduce the load on your original data and prevent unnecessary queries from affecting performance.
3. **Simplified Complex Queries**: Materialized views allow you to simplify complex queries by providing a pre-computed result.

**Real-World Scenarios:**

1. **Data Warehousing**: Materialized views are particularly useful in data warehousing scenarios where you need to frequently aggregate data and provide fast query response times.
2. **Analytics Applications**: In analytics applications, materialized views can help speed up complex calculations and reports.
3. **E-commerce Platforms**: As mentioned earlier, materialized views can be used to pre-compute top-selling products or other common queries.

**TL;DR:**
Materialized views are pre-computed results of a database query that improve query performance by storing actual data in a physical table. They reduce the load on original data, simplify complex queries, and provide fast query response times.