8 files changed, 24 insertions, 21 deletions
diff --git a/activerecord/RUNNING_UNIT_TESTS b/activerecord/RUNNING_UNIT_TESTS
index 16444249cc..8fe9a357b4 100644
--- a/activerecord/RUNNING_UNIT_TESTS
+++ b/activerecord/RUNNING_UNIT_TESTS
@@ -9,24 +9,26 @@ You can build postgres and mysql databases using the build_postgresql and build_
 
 You can run a particular test file from the command line, e.g.
 
-  $ ruby test/cases/base_test.rb
+  $ ruby -Itest test/cases/base_test.rb
 
 To run a specific test:
 
-  $ ruby test/cases/base_test.rb -n test_something_works
+  $ ruby -Itest test/cases/base_test.rb -n test_something_works
 
 You can run with a database other than the default you set in test/config.yml, using the ARCONN
 environment variable:
 
-  $ ARCONN=postgresql ruby test/cases/base_test.rb
+  $ ARCONN=postgresql ruby -Itest test/cases/base_test.rb
 
 You can run all the tests for a given database via rake:
 
-To setup the testing environment for PostgreSQL use this command:
+  $ rake test_mysql
 
-  rake postgresql:build_databases
+The 'rake test' task will run all the tests for mysql, mysql2, sqlite3 and postgresql.
 
-The incantation for running a particular test looks like this
+== Identity Map
 
-  rake test TEST=test/cases/datatype_test_postgresql.rb TESTOPTS="--name=test_timestamp_with_zone_values_without_rails_time_zone_support"
+By default the tests run with the Identity Map turned off. But all tests should pass whether or
+not the identity map is on or off. You can turn it on using the IM env variable:
 
+  $ IM=true ruby -Itest test/case/base_test.rb
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)
 
diff --git a/activerecord/test/cases/adapters/mysql2/reserved_word_test.rb b/activerecord/test/cases/adapters/mysql2/reserved_word_test.rb
index 752b864818..3a9744e78f 100644
--- a/activerecord/test/cases/adapters/mysql2/reserved_word_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/reserved_word_test.rb
@@ -87,8 +87,8 @@ class MysqlReservedWordTest < ActiveRecord::TestCase
     assert_nothing_raised { x.save }
     x.order = 'y'
     assert_nothing_raised { x.save }
-    assert_nothing_raised { y = Group.find_by_order('y') }
-    assert_nothing_raised { y = Group.find(1) }
+    assert_nothing_raised { Group.find_by_order('y') }
+    assert_nothing_raised { Group.find(1) }
     x = Group.find(1)
   end
 
diff --git a/activerecord/test/cases/associations/join_model_test.rb b/activerecord/test/cases/associations/join_model_test.rb
index f22a91be2d..4ce8b85098 100644
--- a/activerecord/test/cases/associations/join_model_test.rb
+++ b/activerecord/test/cases/associations/join_model_test.rb
@@ -722,8 +722,8 @@ class AssociationsJoinModelTest < ActiveRecord::TestCase
   end
 
   def test_has_many_with_pluralize_table_names_false
-    engine = Engine.create!(:car_id => 1)
-    aircraft = Aircraft.create!(:name => "Airbus 380", :id => 1)
+    aircraft = Aircraft.create!(:name => "Airbus 380")
+    engine = Engine.create!(:car_id => aircraft.id)
     assert_equal aircraft.engines, [engine]
   end
 
diff --git a/activerecord/test/cases/helper.rb b/activerecord/test/cases/helper.rb
index 110f6b97c6..d0dc9cb03d 100644
--- a/activerecord/test/cases/helper.rb
+++ b/activerecord/test/cases/helper.rb
@@ -12,19 +12,20 @@ require 'active_support/dependencies'
 require 'support/config'
 require 'support/connection'
 
-ARTest.connect
-
 # TODO: Move all these random hacks into the ARTest namespace and into the support/ dir
 
 # Show backtraces for deprecated behavior for quicker cleanup.
 ActiveSupport::Deprecation.debug = true
 
-# Quote "type" if it's a reserved word for the current connection.
-QUOTED_TYPE = ActiveRecord::Base.connection.quote_column_name('type')
-
 # Enable Identity Map only when ENV['IM'] is set to "true"
 ActiveRecord::IdentityMap.enabled = (ENV['IM'] == "true")
 
+# Connect to the database
+ARTest.connect
+
+# Quote "type" if it's a reserved word for the current connection.
+QUOTED_TYPE = ActiveRecord::Base.connection.quote_column_name('type')
+
 def current_adapter?(*types)
   types.any? do |type|
     ActiveRecord::ConnectionAdapters.const_defined?(type) &&
diff --git a/activerecord/test/support/connection.rb b/activerecord/test/support/connection.rb
index fcd2e4dee5..a39794fa39 100644
--- a/activerecord/test/support/connection.rb
+++ b/activerecord/test/support/connection.rb
@@ -11,7 +11,7 @@ module ARTest
   end
 
   def self.connect
-    puts "Using #{connection_name}"
+    puts "Using #{connection_name} with Identity Map #{ActiveRecord::IdentityMap.enabled? ? 'on' : 'off'}"
     ActiveRecord::Base.logger = Logger.new("debug.log")
     ActiveRecord::Base.configurations = connection_config
     ActiveRecord::Base.establish_connection 'arunit'