5 files changed, 60 insertions, 21 deletions
diff --git a/railties/guides/source/active_record_querying.textile b/railties/guides/source/active_record_querying.textile
index ad12dca7e8..c4724f182e 100644
--- a/railties/guides/source/active_record_querying.textile
+++ b/railties/guides/source/active_record_querying.textile
@@ -1287,6 +1287,7 @@ User.where(:id => 1).joins(:posts).explain
 may yield
 
 <plain>
+EXPLAIN for: SELECT `users`.* FROM `users` INNER JOIN `posts` ON `posts`.`user_id` = `users`.`id` WHERE `users`.`id` = 1
 <plus>----<plus>-------------<plus>-------<plus>-------<plus>---------------<plus>---------<plus>---------<plus>-------<plus>------<plus>-------------<plus>
 | id | select_type | table | type  | possible_keys | key     | key_len | ref   | rows | Extra       |
 <plus>----<plus>-------------<plus>-------<plus>-------<plus>---------------<plus>---------<plus>---------<plus>-------<plus>------<plus>-------------<plus>
@@ -1302,6 +1303,7 @@ Active Record performs a pretty printing that emulates the one of the database
 shells. So, the same query running with the PostgreSQL adapter would yield instead
 
 <plain>
+EXPLAIN for: SELECT "users".* FROM "users" INNER JOIN "posts" ON "posts"."user_id" = "users"."id" WHERE "users"."id" = 1
                                   QUERY PLAN
 ------------------------------------------------------------------------------
  Nested Loop Left Join  (cost=0.00..37.24 rows=8 width=0)
@@ -1324,12 +1326,15 @@ User.where(:id => 1).includes(:posts).explain
 yields
 
 <plain>
+EXPLAIN for: SELECT `users`.* FROM `users`  WHERE `users`.`id` = 1
 <plus>----<plus>-------------<plus>-------<plus>-------<plus>---------------<plus>---------<plus>---------<plus>-------<plus>------<plus>-------<plus>
 | id | select_type | table | type  | possible_keys | key     | key_len | ref   | rows | Extra |
 <plus>----<plus>-------------<plus>-------<plus>-------<plus>---------------<plus>---------<plus>---------<plus>-------<plus>------<plus>-------<plus>
 |  1 | SIMPLE      | users | const | PRIMARY       | PRIMARY | 4       | const |    1 |       |
 <plus>----<plus>-------------<plus>-------<plus>-------<plus>---------------<plus>---------<plus>---------<plus>-------<plus>------<plus>-------<plus>
 1 row in set (0.00 sec)
+
+EXPLAIN for: SELECT `posts`.* FROM `posts`  WHERE `posts`.`user_id` IN (1)
 <plus>----<plus>-------------<plus>-------<plus>------<plus>---------------<plus>------<plus>---------<plus>------<plus>------<plus>-------------<plus>
 | id | select_type | table | type | possible_keys | key  | key_len | ref  | rows | Extra       |
 <plus>----<plus>-------------<plus>-------<plus>------<plus>---------------<plus>------<plus>---------<plus>------<plus>------<plus>-------------<plus>
@@ -1339,3 +1344,14 @@ yields
 </plain>
 
 under MySQL.
+
+h4. Interpreting EXPLAIN
+
+Interpretation of the output of EXPLAIN is beyond the scope of this guide. The
+following pointers may be helpful:
+
+* SQLite3: "EXPLAIN QUERY PLAN":http://www.sqlite.org/eqp.html
+
+* MySQL: "EXPLAIN Output Format":http://dev.mysql.com/doc/refman/5.6/en/explain-output.html
+
+* PostgreSQL: "Using EXPLAIN":http://www.postgresql.org/docs/current/static/using-explain.html
diff --git a/railties/guides/source/active_support_core_extensions.textile b/railties/guides/source/active_support_core_extensions.textile
index ff6c5f967f..2dee440b3b 100644
--- a/railties/guides/source/active_support_core_extensions.textile
+++ b/railties/guides/source/active_support_core_extensions.textile
@@ -571,7 +571,7 @@ NOTE: Defined in +active_support/core_ext/module/attr_accessor_with_default.rb+.
 
 h5. Internal Attributes
 
-When you are defining an attribute in a class that is meant to be subclassed name collisions are a risk. That's remarkably important for libraries.
+When you are defining an attribute in a class that is meant to be subclassed, name collisions are a risk. That's remarkably important for libraries.
 
 Active Support defines the macros +attr_internal_reader+, +attr_internal_writer+, and +attr_internal_accessor+. They behave like their Ruby built-in +attr_*+ counterparts, except they name the underlying instance variable in a way that makes collisions less likely.
 
@@ -3039,15 +3039,30 @@ Active Support defines these methods as well for Ruby 1.8.
 
 h6. +beginning_of_week+, +end_of_week+
 
-The methods +beginning_of_week+ and +end_of_week+ return the dates for the beginning and end of week, assuming weeks start on Monday:
+The methods +beginning_of_week+ and +end_of_week+ return the dates for the
+beginning and end of the week, respectively. Weeks are assumed to start on
+Monday, but that can be changed passing an argument.
 
 <ruby>
-d = Date.new(2010, 5, 8) # => Sat, 08 May 2010
-d.beginning_of_week      # => Mon, 03 May 2010
-d.end_of_week            # => Sun, 09 May 2010
+d = Date.new(2010, 5, 8)     # => Sat, 08 May 2010
+d.beginning_of_week          # => Mon, 03 May 2010
+d.beginning_of_week(:sunday) # => Sun, 02 May 2010
+d.end_of_week                # => Sun, 09 May 2010
+d.end_of_week(:sunday)       # => Sat, 08 May 2010
 </ruby>
 
-+beginning_of_week+ is aliased to +monday+ and +at_beginning_of_week+. +end_of_week+ is aliased to +sunday+ and +at_end_of_week+.
++beginning_of_week+ is aliased to +at_beginning_of_week+ and +end_of_week+ is aliased to +at_end_of_week+.
+
+h6. +monday+, +sunday+
+
+The methods +monday+ and +sunday+ return the dates for the beginning and
+end of the week, respectively. Weeks are assumed to start on Monday.
+
+<ruby>
+d = Date.new(2010, 5, 8)     # => Sat, 08 May 2010
+d.monday                     # => Mon, 03 May 2010
+d.sunday                     # => Sun, 09 May 2010
+</ruby>
 
 h6. +prev_week+, +next_week+
 
@@ -3272,8 +3287,10 @@ The class +DateTime+ is a subclass of +Date+ so by loading +active_support/core_
 <ruby>
 yesterday
 tomorrow
-beginning_of_week (monday, at_beginning_of_week)
-end_on_week (at_end_of_week)
+beginning_of_week (at_beginning_of_week)
+end_of_week (at_end_of_week)
+monday
+sunday
 weeks_ago
 prev_week
 next_week
@@ -3446,8 +3463,10 @@ ago
 since (in)
 beginning_of_day (midnight, at_midnight, at_beginning_of_day)
 end_of_day
-beginning_of_week (monday, at_beginning_of_week)
-end_on_week (at_end_of_week)
+beginning_of_week (at_beginning_of_week)
+end_of_week (at_end_of_week)
+monday
+sunday
 weeks_ago
 prev_week
 next_week
diff --git a/railties/guides/source/configuring.textile b/railties/guides/source/configuring.textile
index cd6e7d116e..809948b41e 100644
--- a/railties/guides/source/configuring.textile
+++ b/railties/guides/source/configuring.textile
@@ -263,6 +263,8 @@ h4. Configuring Active Record
 
 * +config.active_record.whitelist_attributes+ will create an empty whitelist of attributes available for mass-assignment security for all models in your app.
 
+* +config.active_record.identity_map+ controls whether the identity map is enabled, and is false by default.
+
 The MySQL adapter adds one additional configuration option:
 
 * +ActiveRecord::ConnectionAdapters::MysqlAdapter.emulate_booleans+ controls whether Active Record will consider all +tinyint(1)+ columns in a MySQL database to be booleans and is true by default.
diff --git a/railties/guides/source/getting_started.textile b/railties/guides/source/getting_started.textile
index fde83ae730..ca6a404212 100644
--- a/railties/guides/source/getting_started.textile
+++ b/railties/guides/source/getting_started.textile
@@ -450,6 +450,8 @@ start a web server on your development machine. You can do this by running:
 $ rails server
 </shell>
 
+TIP: Compiling CoffeeScript to JavaScript requires a JavaScript runtime and the absence of a runtime will give you an +execjs+ error. Usually Mac OS X and Windows come with a JavaScript runtime installed. +therubyracer+ and +therubyrhino+ are the commonly used runtimes for Ruby and JRuby respectively. You can also investigate a list of runtimes at "ExecJS":https://github.com/sstephenson/execjs.
+
 This will fire up an instance of the WEBrick web server by default (Rails can
 also use several other web servers). To see your application in action, open a
 browser window and navigate to "http://localhost:3000":http://localhost:3000.
diff --git a/railties/guides/source/initialization.textile b/railties/guides/source/initialization.textile
index 036b356a37..5ae9cf0f2b 100644
--- a/railties/guides/source/initialization.textile
+++ b/railties/guides/source/initialization.textile
@@ -17,7 +17,7 @@ As of Rails 3, +script/server+ has become +rails server+. This was done to centr
 
 h4. +bin/rails+
 
-The actual +rails+ command is kept in _bin/rails_ at the and goes like this:
+The actual +rails+ command is kept in _bin/rails_:
 
 <ruby>
 #!/usr/bin/env ruby
@@ -31,7 +31,7 @@ rescue LoadError
 end
 </ruby>
 
-This file will attempt to load +rails/cli+ and if it cannot find it then add the +railties/lib+ path to the load path (+$:+) and will then try to require it again.
+This file will attempt to load +rails/cli+. If it cannot find it then +railties/lib+ is added to the load path (+$:+) before retrying.
 
 h4. +railties/lib/rails/cli.rb+
 
@@ -56,7 +56,7 @@ else
 end
 </ruby>
 
-The +rbconfig+ file here is out of Ruby's standard library and provides us with the +RbConfig+ class which contains useful information dependent on how Ruby was compiled. We'll see this in use in +railties/lib/rails/script_rails_loader+.
+The +rbconfig+ file from the Ruby standard library provides us with the +RbConfig+ class which contains detailed information about the Ruby environment, including how Ruby was compiled. We can see this in use in +railties/lib/rails/script_rails_loader+.
 
 <ruby>
 require 'pathname'
@@ -71,7 +71,7 @@ module Rails
 end
 </ruby>
 
-The +rails/script_rails_loader+ file uses +RbConfig::Config+ to gather up the +bin_dir+ and +ruby_install_name+ values for the configuration which will result in a path such as +/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby+, which is the default path on Mac OS X. If you're running Windows the path may be something such as +C:/Ruby192/bin/ruby+. Anyway, the path on your system may be different, but the point of this is that it will point at the known ruby executable location for your install. The +RbConfig::CONFIG["EXEEXT"]+ will suffix this path with ".exe" if the script is running on Windows. This constant is used later on in +exec_script_rails!+. As for the +SCRIPT_RAILS+ constant, we'll see that when we get to the +in_rails_application?+ method.
+The +rails/script_rails_loader+ file uses +RbConfig::Config+ to obtain the +bin_dir+ and +ruby_install_name+ values for the configuration which together form the path to the Ruby interpreter. The +RbConfig::CONFIG["EXEEXT"]+ will suffix this path with ".exe" if the script is running on Windows. This constant is used later on in +exec_script_rails!+. As for the +SCRIPT_RAILS+ constant, we'll see that when we get to the +in_rails_application?+ method.
 
 Back in +rails/cli+, the next line is this:
 
@@ -79,7 +79,7 @@ Back in +rails/cli+, the next line is this:
 Rails::ScriptRailsLoader.exec_script_rails!
 </ruby>
 
-This method is defined in +rails/script_rails_loader+ like this:
+This method is defined in +rails/script_rails_loader+:
 
 <ruby>
 def self.exec_script_rails!
@@ -96,7 +96,7 @@ rescue SystemCallError
 end
 </ruby>
 
-This method will first check if the current working directory (+cwd+) is a Rails application or is a subdirectory of one. The way to determine this is defined in the +in_rails_application?+ method like this:
+This method will first check if the current working directory (+cwd+) is a Rails application or a subdirectory of one. This is determined by the +in_rails_application?+ method:
 
 <ruby>
 def self.in_rails_application?
@@ -104,7 +104,7 @@ def self.in_rails_application?
 end
 </ruby>
 
-The +SCRIPT_RAILS+ constant defined earlier is used here, with +File.exists?+ checking for its presence in the current directory. If this method returns +false+, then +in_rails_application_subdirectory?+ will be used:
+The +SCRIPT_RAILS+ constant defined earlier is used here, with +File.exists?+ checking for its presence in the current directory. If this method returns +false+ then +in_rails_application_subdirectory?+ will be used:
 
 <ruby>
 def self.in_rails_application_subdirectory?(path = Pathname.new(Dir.pwd))
@@ -112,17 +112,17 @@ def self.in_rails_application_subdirectory?(path = Pathname.new(Dir.pwd))
 end
 </ruby>
 
-This climbs the directory tree until it reaches a path which contains a +script/rails+ file. If a directory is reached which contains this file then this line will run:
+This climbs the directory tree until it reaches a path which contains a +script/rails+ file. If a directory containing this file is reached then this line will run:
 
 <ruby>
 exec RUBY, SCRIPT_RAILS, *ARGV if in_rails_application?
 </ruby>
 
-This is effectively the same as doing +ruby script/rails [arguments]+. Where +[arguments]+ at this point in time is simply "server".
+This is effectively the same as running +ruby script/rails [arguments]+, where +[arguments]+ at this point in time is simply "server".
 
 h4. +script/rails+
 
-This file looks like this:
+This file is as follows:
 
 <ruby>
 APP_PATH = File.expand_path('../../config/application',  __FILE__)
@@ -130,7 +130,7 @@ require File.expand_path('../../config/boot',  __FILE__)
 require 'rails/commands'
 </ruby>
 
-The +APP_PATH+ constant here will be used later in +rails/commands+. The +config/boot+ file that +script/rails+ references is the +config/boot.rb+ file in our application which is responsible for loading Bundler and setting it up.
+The +APP_PATH+ constant will be used later in +rails/commands+. The +config/boot+ file referenced here is the +config/boot.rb+ file in our application which is responsible for loading Bundler and setting it up.
 
 h4. +config/boot.rb+