MariaDB 13.0: optimizer hints with MySQL-compatible syntax

MariaDB Server 13.0 introduces a complete set of optimizer hints with MySQL-compatible syntax. For database administrators running production workloads on VPS or bare metal, this means being able to force specific optimizer choices on a per-query basis, without touching global server parameters.

The syntax

The same format introduced by MySQL 8.0:

SELECT /*+ hint1(arguments) hint2(arguments) */ ...
FROM t1
WHERE a IN (SELECT /*+ hint3(arguments) */ ...);

The hints allow you to control table join order, index usage, join buffer utilisation, derived table merging, condition pushdown into derived tables, subquery execution strategies, and optimisations such as MRR, ICP, range optimisation, rowid filtering, lateral derived tables, as well as maximum execution time.

Oleg Smirnov, Senior Software Engineer at MariaDB plc, authored the technical post explaining the new feature on the official blog.

Where MariaDB differs from MySQL

Feature	MySQL 8.0	MariaDB 13.0
Hints inside a view	Index hints only	Any hint except MAX_EXECUTION_TIME
Query block reference	Requires explicit QB_NAME	Implicit names by position, alias, or explicit path
Inspiration	—	TiDB, for explicit path on query blocks

The most practical difference concerns views: with MariaDB you can write CREATE VIEW v1 AS SELECT /*+ NO_MRR(t1 idx_a) JOIN_ORDER(t2, t1)*/..., something that MySQL does not permit outside index hints.

Timeline for the 13.0 series

Those deciding whether to upgrade can find verified milestones on the official changelog: preview on 23 March 2026, release candidate 13.0.1 on 29 May 2026, stable 13.0.2 on 15 September 2026. The series remains a rolling release: for those seeking extended maintenance and slower upgrade cycles, MariaDB recommends staying on the 12.3 LTS series.

Where to find the documentation

The complete list of hints with examples is on the official documentation page. To report bugs or request new hints, the designated channel is the project JIRA, under ticket MDEV-38045 regarding QB_NAME().