How do database views differ from materialized views?

1 View Basics

Database views are defined using Structured Query Language (SQL) and act like a virtual table that provides a specific, predefined perspective of your data. When you query a view, the database engine dynamically generates the result set using the view's defining SQL statement. This is beneficial because it abstracts complex queries, simplifies data access, and enhances security by limiting user access to specific data. However, since the data is not stored, every time you access the view, the database must execute the SQL query, which can impact performance if the underlying query is complex or involves large datasets.

4 Refresh Mechanisms

The refresh mechanism is another aspect where these two types of views differ. With a standard view, there's no need for a refresh since it's always accessing live data. Materialized views, however, must be refreshed periodically to ensure they represent the most recent data. The refresh can be done manually or automatically based on a schedule or triggered by certain events. This process can be resource-intensive, so it's important to balance the need for up-to-date data with the system's performance.

6 Security Features

From a security standpoint, both views and materialized views offer advantages. They can both be used to restrict access to specific columns or rows, thereby implementing a level of row-level and column-level security. By carefully designing views, you can expose only the necessary information to users, minimizing the risk of unauthorized access to sensitive data. However, since materialized views store data, they may require additional security considerations to protect the stored result sets.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?