From d1c474ae6aa98e281cdc46da183a0c29a324ba31 Mon Sep 17 00:00:00 2001
From: Tomasz Maczukin <tomasz@maczukin.pl>
Date: Mon, 18 Jan 2016 15:52:26 +0100
Subject: [PATCH] Add information about PostgreSQL<>MySQL 'text' type
differences into to installation docs
---
doc/install/database_mysql.md | 19 +++++++++++++++++++
doc/update/README.md | 1 +
2 files changed, 20 insertions(+)
diff --git a/doc/install/database_mysql.md b/doc/install/database_mysql.md
index 513ad69ec26..4a2c699129d 100644
--- a/doc/install/database_mysql.md
+++ b/doc/install/database_mysql.md
@@ -52,3 +52,22 @@ We do not recommend using MySQL due to various issues. For example, case [(in)se
mysql> \q
# You are done installing the database and can go back to the rest of the installation.
+
+## MySQL strings limits
+
+After installation or upgrade is done, remember to run `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!
+
+`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).
+
+Details can be found in [PostgreSQL manual][postgres-text-type] and in [MySQL manual][mysql-text-types].
+
+[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
diff --git a/doc/update/README.md b/doc/update/README.md
index 0472537eeb5..46aec4885e2 100644
--- a/doc/update/README.md
+++ b/doc/update/README.md
@@ -14,3 +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.
--
GitLab