What’s New in MySQL 9.0? Key Features, Deprecations, and Upgrade Tips

At the start of July, Oracle released three major MySQL versions: MySQL 8.0.38, the first update of the long‑term support (LTS) line MySQL 8.4, and the inaugural major release of the 9.x Innovation series, MySQL 9.0.

While the 8.x updates contain only bug fixes and security patches, MySQL 9.0 Innovation is a “shiny” new release with additional features and some changes to be aware of when upgrading from earlier versions.

The new MySQL 9.0 client, tools, and connectors are also available, and Oracle recommends using them together with MySQL Server 8.0, 8.4 LTS, and the 9.0 Innovation version.

MySQL 9.0.0 New Features

Oracle states that the initial 9.x Innovation version prepares for new features in upcoming releases. It still contains useful additions and can be upgraded from MySQL 8.4 LTS; on Windows, the MSI installer automatically upgrades via MySQL Configurator without user intervention.

CREATE and ALTER statements now support a new Vector data type.

JavaScript stored procedures are supported, allowing JavaScript‑based routines and functions (available in MySQL Enterprise Edition). JavaScript stored procedures can call SQL, and SQL can call them.

MySQL 9.0 Innovation moves to newer libraries and compilers: Linux builds on GCC 13 and Boost 1.85.

The event scheduler now permits preparing SQL statements CREATE EVENT, ALTER EVENT, and DROP EVENT.

Features Removed in MySQL 9.0

Insecure and outdated SHA‑1 authentication, deprecated in MySQL 8, has been completely removed; the server now rejects mysql_native authentication requests from old clients lacking the CLIENT_PLUGIN_AUTH capability.

Oracle advises that before upgrading to 9.0, user accounts in 8.0 and 8.4 must be changed from mysql_native_password to caching_sha2_password.

In the optimizer, ER_SUBQUERY_NO_1_ROW has been removed from the list of errors ignored by statements containing the IGNORE keyword.

If UPDATE, DELETE, or INSERT statements include the IGNORE keyword, or SELECT statements contain subqueries that generate multiple rows, the change causes these statements to raise errors.

Future Versions After MySQL 9.0

MySQL is scheduled to release a new version every three months, with a major LTS version every two years.

Oracle indicates that in the upcoming October release, developers can expect bug‑fix and security updates for MySQL 8.4.2 LTS and MySQL 8.0.39, as well as a new MySQL 9.1 Innovation version that includes fresh features and additional bug‑security fixes.