3 files changed, 4 insertions, 4 deletions
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index c2b09ad393..2f283ff6bc 100644
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -659,8 +659,8 @@ module ActiveRecord #:nodoc:
       def set_table_name(value = nil, &block)
         @quoted_table_name = nil
         define_attr_method :table_name, value, &block
+        @arel_table = nil
 
-        @arel_table = Arel::Table.new(table_name, arel_engine)
         @relation = Relation.new(self, arel_table)
       end
       alias :table_name= :set_table_name
@@ -892,7 +892,7 @@ module ActiveRecord #:nodoc:
       end
 
       def arel_table
-        Arel::Table.new(table_name, arel_engine)
+        @arel_table ||= Arel::Table.new(table_name, arel_engine)
       end
 
       def arel_engine
diff --git a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
index 8d7dd8bacf..9e6cb13cca 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
@@ -707,7 +707,7 @@ module ActiveRecord
         def quoted_columns_for_index(column_names, options = {})
           length = options[:length] if options.is_a?(Hash)
 
-          quoted_column_names = case length
+          case length
           when Hash
             column_names.map {|name| length[name] ? "#{quote_column_name(name)}(#{length[name]})" : quote_column_name(name) }
           when Fixnum
diff --git a/activerecord/lib/active_record/railties/databases.rake b/activerecord/lib/active_record/railties/databases.rake
index 6f8f84d50b..6ef24a4eaf 100644
--- a/activerecord/lib/active_record/railties/databases.rake
+++ b/activerecord/lib/active_record/railties/databases.rake
@@ -498,7 +498,7 @@ namespace :railties do
     # desc "Copies missing migrations from Railties (e.g. plugins, engines). You can specify Railties to use with FROM=railtie1,railtie2"
     task :migrations => :'db:load_config' do
       to_load = ENV['FROM'].blank? ? :all : ENV['FROM'].split(",").map {|n| n.strip }
-      railties = {}
+      railties = ActiveSupport::OrderedHash.new
       Rails.application.railties.all do |railtie|
         next unless to_load == :all || to_load.include?(railtie.railtie_name)