Merge branch 'cherry-pick-4e287630' into '8-9-stable'

Merge branch 'doc-mysql-priv' into 'master'

## What does this MR do?

Update missing mysql user permissions.

## Why was this MR needed?

This should also be in the `8-9-stable` branch.


See merge request !5086

doc/install/database_mysql.md

@@ -36,7 +36,7 @@ We do not recommend using MySQL due to various issues. For example, case [(in)se
     mysql> CREATE DATABASE IF NOT EXISTS `gitlabhq_production` DEFAULT CHARACTER SET `utf8` COLLATE `utf8_unicode_ci`;
 
     # Grant the GitLab user necessary permissions on the database
-    mysql> GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, CREATE TEMPORARY TABLES, DROP, INDEX, ALTER, LOCK TABLES ON `gitlabhq_production`.* TO 'git'@'localhost';
+    mysql> GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, CREATE TEMPORARY TABLES, DROP, INDEX, ALTER, LOCK TABLES, REFERENCES ON `gitlabhq_production`.* TO 'git'@'localhost';
 
     # Quit the database session
     mysql> \q

doc/update/8.8-to-8.9.md

@@ -62,7 +62,23 @@ sudo -u git -H git checkout v0.7.5
 sudo -u git -H make
 ```
 
-### 6. Install libs, migrations, etc.
+### 6. Update MySQL permissions
+
+If you are using MySQL you need to grant the GitLab user the necessary
+permissions on the database:
+
+```bash
+# Login to MySQL
+mysql -u root -p
+
+# Grant the GitLab user the REFERENCES permission on the database
+GRANT REFERENCES ON `gitlabhq_production`.* TO 'git'@'localhost';
+
+# Quit the database session
+mysql> \q
+```
+
+### 7. Install libs, migrations, etc.
 
 ```bash
 cd /home/git/gitlab
@@ -84,7 +100,7 @@ sudo -u git -H bundle exec rake assets:clean assets:precompile cache:clear RAILS
 
 ```
 
-### 7. Update configuration files
+### 8. Update configuration files
 
 #### New configuration options for `gitlab.yml`
 
@@ -128,12 +144,12 @@ Ensure you're still up-to-date with the latest init script changes:
 
     sudo cp lib/support/init.d/gitlab /etc/init.d/gitlab
 
-### 8. Start application
+### 9. Start application
 
     sudo service gitlab start
     sudo service nginx restart
 
-### 9. Check application status
+### 10. Check application status
 
 Check if GitLab and its environment are configured correctly: