From 057052142099cb24f103317010ca17ea64f9f2ce Mon Sep 17 00:00:00 2001 From: Stan Hu Date: Fri, 11 Aug 2017 15:34:15 -0700 Subject: [PATCH] Add notes about database performance for MySQL [ci skip] --- doc/install/requirements.md | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/doc/install/requirements.md b/doc/install/requirements.md index 141df55f6bc..175dfc62096 100644 --- a/doc/install/requirements.md +++ b/doc/install/requirements.md @@ -104,6 +104,10 @@ features of GitLab work with MySQL/MariaDB: See [issue #30472][30472] for more information. 1. GitLab 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. 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) 1. We expect this list to grow over time. Existing users using GitLab with MySQL/MariaDB are advised to