Document that GitLab 9.3 requires the TRIGGER permission on MySQL

doc/install/database_mysql.md

@@ -43,7 +43,7 @@ mysql> SET GLOBAL innodb_file_per_table=1, innodb_file_format=Barracuda, innodb_
 mysql> CREATE DATABASE IF NOT EXISTS `gitlabhq_production` DEFAULT CHARACTER SET `utf8` COLLATE `utf8_general_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, REFERENCES ON `gitlabhq_production`.* TO 'git'@'localhost';
+mysql> GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, CREATE TEMPORARY TABLES, DROP, INDEX, ALTER, LOCK TABLES, REFERENCES, TRIGGER ON `gitlabhq_production`.* TO 'git'@'localhost';
 
 # Quit the database session
 mysql> \q

doc/update/9.2-to-9.3.md

@@ -157,7 +157,16 @@ sudo -u git -H git checkout v$(</home/git/gitlab/GITALY_SERVER_VERSION)
 sudo -u git -H make
 ```
 
-### 10. Update configuration files
+### 10. Update MySQL permissions
+
+If you are using MySQL you need to grant the GitLab user the necessary
+permissions on the database:
+
+```bash
+mysql -u root -p -e "GRANT TRIGGER ON \`gitlabhq_production\`.* TO 'git'@'localhost';"
+```
+
+### 11. Update configuration files
 
 #### New configuration options for `gitlab.yml`
 
@@ -231,7 +240,7 @@ For Ubuntu 16.04.1 LTS:
 sudo systemctl daemon-reload
 ```
 
-### 11. Install libs, migrations, etc.
+### 12. Install libs, migrations, etc.
 
 ```bash
 cd /home/git/gitlab
@@ -257,14 +266,14 @@ sudo -u git -H bundle exec rake cache:clear RAILS_ENV=production
 
 **MySQL installations**: Run through the `MySQL strings limits` and `Tables and data conversion to utf8mb4` [tasks](../install/database_mysql.md).
 
-### 12. Start application
+### 13. Start application
 
 ```bash
 sudo service gitlab start
 sudo service nginx restart
 ```
 
-### 13. Check application status
+### 14. Check application status
 
 Check if GitLab and its environment are configured correctly: