Update MySQL docs

[ci skip]

CHANGELOG

@@ -64,7 +64,7 @@ v 8.4.0 (unreleased)
   - Remove leading comma on award emoji when the user is the first to award the emoji (Zeger-Jan van de Weg)
   - Add build artifacts browser
   - Improve UX in builds artifacts browser
-  - Change type of `data` column in `events` table when using MySQL
+  - Increase default size of `data` column in `events` table when using MySQL
 
 v 8.3.4
   - Use gitlab-workhorse 0.5.4 (fixes API routing bug)

doc/install/database_mysql.md

@@ -55,19 +55,22 @@ We do not recommend using MySQL due to various issues. For example, case [(in)se
 
 ## MySQL strings limits
 
-After installation or upgrade is done, remember to run `add_limits_mysql` rake task:
+After installation or upgrade, remember to run the `add_limits_mysql` Rake task:
 
 ```
 bundle exec rake add_limits_mysql
 ```
 
-The `text` type in MySQL have different size limit than `text` type in PostgreSQL. In MySQL `text` columns are limited
-to ~65kB, where in PostgreSQL `text` columns are limited up to ~1GB!
+The `text` type in MySQL has a different size limit than the `text` type in
+PostgreSQL. In MySQL `text` columns are limited to ~65kB, whereas in PostgreSQL
+`text` columns are limited up to ~1GB!
 
-`add_limits_mysql` rake task converts some important `text` columns in GitLab database to `longtext` which can persist
-up to 4GB characters (may be less if the value contains multibyte characters).
+The `add_limits_mysql` Rake task converts some important `text` columns in the
+GitLab database to `longtext` columns, which can persist values of up to 4GB
+(sometimes less if the value contains multibyte characters).
 
-Details can be found in [PostgreSQL manual][postgres-text-type] and in [MySQL manual][mysql-text-types].
+Details can be found in the [PostgreSQL][postgres-text-type] and
+[MySQL][mysql-text-types] manuals.
 
 [postgres-text-type]: http://www.postgresql.org/docs/9.1/static/datatype-character.html
 [mysql-text-types]: http://dev.mysql.com/doc/refman/5.7/en/string-type-overview.html

doc/update/README.md

@@ -14,4 +14,4 @@ Depending on the installation method and your GitLab version, there are multiple
 ## Miscellaneous
 
 - [MySQL to PostgreSQL](mysql_to_postgresql.md) guides you through migrating your database from MySQL to PostgreSQL.
-- [MySQL installation guide](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/install/database_mysql.md) contains additional informations about configuring GitLab to work with MySQL database.
+- [MySQL installation guide](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/install/database_mysql.md) contains additional information about configuring GitLab to work with a MySQL database.