@@ -103,14 +103,17 @@ features of GitLab work with MySQL/MariaDB:
1. MySQL support for subgroups was [dropped with GitLab 9.3][post].
See [issue #30472][30472] for more information.
1. Geo does [not support MySQL](https://docs.gitlab.com/ee/gitlab-geo/database.html#mysql-replication).
1.[Zero downtime migrations][zero] do not work with MySQL
1. Geo **[STARTER ONLY]** does [not support MySQL](https://docs.gitlab.com/ee/gitlab-geo/database.html#mysql-replication). This means no supported Disaster Recovery solution if using MySQL.
1.[Zero downtime migrations][zero] do not work with MySQL.
1.[Database load balancing](../administration/database_load_balancing.md) is
supported only for PostgreSQL.
1. GitLab [optimizes the loading of dashboard events](https://gitlab.com/gitlab-org/gitlab-ce/issues/31806) using [PostgreSQL LATERAL JOINs](https://blog.heapanalytics.com/postgresqls-powerful-new-join-type-lateral/).
1. In general, SQL optimized for PostgreSQL may run much slower in MySQL due to
differences in query planners. For example, subqueries that work well in PostgreSQL
may not be [performant in MySQL](https://dev.mysql.com/doc/refman/5.7/en/optimizing-subqueries.html)
may not be [performant in MySQL](https://dev.mysql.com/doc/refman/5.7/en/optimizing-subqueries.html).
1. Binary column index length is limited to 20 bytes. This is accomplished with [a hack](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/config/initializers/mysql_set_length_for_binary_indexes.rb).
1. MySQL requires a variety of hacks to increase limits on various columns, [for example](https://gitlab.com/gitlab-org/gitlab-ce/issues/49583).
1.[The milestone filter runs slower queries on MySQL](https://gitlab.com/gitlab-org/gitlab-ce/issues/51173#note_99391731).
1. We expect this list to grow over time.
Existing users using GitLab with MySQL/MariaDB are advised to
