tristanm · November 22, 2024 15:47 · May 8, 2015 · May 8, 2015 · May 8, 2015
diff --git a/pgloader-commands b/pgloader-commands
@@ -9,4 +9,5 @@ LOAD DATABASE
 --            job using rake db:schema:load.
 -- truncate:  Ensure all tables are empty first (especially schema_migrations).
 --            WARNING: THIS WILL SMOKE YOUR DATABASE!
+
 WITH data only, truncate;
diff --git a/README.md b/README.md
@@ -2,7 +2,7 @@
 
 This brief guide is written from my own experience with migrating a large (~5GB) MySQL database to PostgreSQL for a Rails project.
 
-No warranties, guarantees, support etc. Use at your own risk and, as always, _ENSURE YOU MAKE BACKUPS FIRST_!
+No warranties, guarantees, support etc. Use at your own risk and, as always, __ENSURE YOU MAKE BACKUPS FIRST__!
 
 I chose [`pgloader`][1] because it's extremely fast. YMMV.
 

diff --git a/README.md b/README.md
@@ -0,0 +1,22 @@
+# Migrating a Rails project from MySQL to PostgreSQL
+
+This brief guide is written from my own experience with migrating a large (~5GB) MySQL database to PostgreSQL for a Rails project.
+
+No warranties, guarantees, support etc. Use at your own risk and, as always, _ENSURE YOU MAKE BACKUPS FIRST_!
+
+I chose [`pgloader`][1] because it's extremely fast. YMMV.
+
+1. Replace `mysql2` gem with `pg` in `Gemfile`.
+2. Update `config/database.yml` for PostgreSQL. I used [Rails' template][2] as a starting point.
+3. Run `rake db:create` to generate your shiney new PostgreSQL DB.
+4. Go through `db/schema.rb` and ensure no `limit` options exist on boolean columns (a bug which has been [fixed][3] but not released).
+5. Run `rake db:schema:load` to setup the schema.
+6. Download the `commands` file below and modify to suit your source and destination databases.
+7. Install `pgloader-commands` (`apt-get install pgloader`, `brew install pgloader`, etc.).
+8. Run `pgloader --verbose commands`, sit back and enjoy the show.
+
+Please leave comments with your own experiences!
+
+[1]: https://github.com/dimitri/pgloader
+[2]: https://github.com/rails/rails/blob/master/railties/lib/rails/generators/rails/app/templates/config/databases/postgresql.yml
+[3]: https://github.com/rails/rails/pull/19066
diff --git a/pgloader-commands b/pgloader-commands
@@ -0,0 +1,12 @@
+-- See https://github.com/dimitri/pgloader/blob/master/pgloader.1.md for 
+-- connection string options.
+
+LOAD DATABASE
+    FROM mysql://root@localhost/source_database
+    INTO postgresql:///destination_database
+
+-- data-only: We don't need pgloader to touch the schema as Rails does a better
+--            job using rake db:schema:load.
+-- truncate:  Ensure all tables are empty first (especially schema_migrations).
+--            WARNING: THIS WILL SMOKE YOUR DATABASE!
+WITH data only, truncate;