Seamless Schema Changes: Mastering Non-Blocking ALTER TABLE in MariaDB

01.02.2026, 14:00 CET

Silversquare delta, Avenue Arnaud Fraiteur 15-23, 1050 Brussels – Belgium

Abstract

We often hear the fear of downtime, that prevents timely yet necessary schema changes. Traditional database systems frequently block DML operations (INSERT, UPDATE, DELETE) for the duration of an ALTER TABLE operation, leading to unacceptable service interruptions.

MariaDB engineers have been long-working on resolving this dilemma, resulting in an anthology of techniques known as Online Schema change.

The session will explore these MariaDB’s robust and mature capabilities.

Key Takeaways for Attendees:

• The underlying mechanisms that allow MariaDB to perform operations like adding columns, creating indexes, or changing data types without locking out writes.
• Practical examples and syntax for enforcing the non-blocking options.
• How Innodb engine capabilities compare to server-wiseOnlineapproach.
• How MariaDB’s approach compares to other database systems in delivering true concurrency during schema modifications.

Speaker: Nikita Malyavin @MariaDB