Watch Federico Razzoli, Consultant as he presents "Virtual Columns in MySQL and MariaDB".

MariaDB 5.2 and MySQL 5.7 introduced virtual columns, with different implementations.

Their features and limitations are similar, but not identical. The main difference is that only MySQL allows you to build an index on a non-persistent column.

In this talk we'll present some use cases for virtual columns, such as query simplification and UNIQUE constraints based on an SQL expression. In particular, we will see how to use virtual columns to index JSON data in MySQL, or dynamic columns in MariaDB.

Performance and limitations will also be discussed.