Can't Rails 3 run in MySQL MyISAM mode, without InnoDB? - ruby-on-rails

Question

I have a MySQL server running with InnoDB disabled (for reasons of performance), with this setup I can't seem to be able to use Rails 3 (with the mysql2 adapter).
Here's my test migration:
class CreateTxts < ActiveRecord::Migration
def change
create_table(:txts, :options => 'ENGINE=MyISAM') do |t|
t.timestamps
end
end
end
And here's the error:
>rake db:migrate
rake aborted!
Mysql2::Error: Unknown storage engine 'InnoDB': CREATE TABLE `schema_migrations`
(`version` varchar(255) NOT NULL) ENGINE=InnoDB
Tried the workaround described here, but it doesn't seem to work either (I did modify MysqlAdapter to Mysql2Adapter to match my setup).
Sorry I'm a newb in Rails. Any help will be much appreciated :o

Answer 1

Going to answer my own question. Here's a patch for environment.rb I ended up with that works with the native mysql driver as well as JRuby/JDBC-mysql:
# Load the rails application
require File.expand_path('../application', __FILE__)
# Patch Mysql adapter to default to MyISAM instead of InnoDB
require 'active_record/connection_adapters/mysql_adapter'
module ActiveRecord
module ConnectionAdapters
class MysqlAdapter
def create_table(table_name, options = {}) #:nodoc:
super(table_name, options.reverse_merge(:options => "ENGINE=MyISAM"))
end
end
end
end
# Initialize the rails application
.....
rake db:migrate now succeeds and creates all tables including schema_migrations with TYPE=MyISAM.
Note: For mysql2 adapter, rename mysql_adapter to mysql2_adapter and MysqlAdapter to Mysql2Adapter.

Answer 2

Try creating the table without specifying the type of engine being used like this
class CreateTxts < ActiveRecord::Migration
def change
create_table(:txts) do |t|
t.timestamps
end
end
end
and then in mysql cli, type this
ALTER TABLE txts ENGINE = MYISAM
hope it helps

Answer 3

The error is coming from creating the schema_migrations table (which rails uses to track which migrations have been run) rather than your table. You could create that table yourself (with a single varchar(255) column called version with an index on it).
If you do end up overwriting the create_table method, you need to preserve the method's signature - you're ignoring the block that it yields. I'd try something like
def create_table(name, options={})
super(name, options.merge(...)) {|t| yield t}
end

Answer 4

#rustyx nice one! &here's my slightly tweaked monkey-patch so the engine can be set from within the /config/database.yml configuration:
&Rather than in /config/environment.rb, i put the codes into an initializer, Eg: /config/initializers/mysql2adapter_default_engine.rb.
Either this for brevity:
require 'active_record/connection_adapters/abstract_mysql_adapter'
class ActiveRecord::ConnectionAdapters::Mysql2Adapter < ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter
def create_table(table_name, options = {}) #:nodoc:
super(table_name, #config[:engine].nil? ? options : options.reverse_merge(:options => "ENGINE="+#config[:engine]))
end
end
or this for more clarity:
require 'active_record/connection_adapters/abstract_mysql_adapter'
module ActiveRecord
module ConnectionAdapters
class Mysql2Adapter < AbstractMysqlAdapter
def create_table(table_name, options = {}) #:nodoc:
super(table_name, #config[:engine].nil? ? options : options.reverse_merge(:options => "ENGINE="+#config[:engine]))
end
end
end
end
Then in /config/database.yml we can have something like this:
production:
adapter: mysql2
encoding: utf8
database: ooook
username: ooook
password: ooook
host: ooook.tld
port: 3306
pool: 5
timeout: 5000
engine: MyISAM
If no engine is specified then the mysql2 adapter will use the default (InnoDB or whatever).