Merge branch 'master' of github.com:rails/rails

17 files changed, 648 insertions, 263 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb b/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
index 1754e424b8..bf2f945448 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
@@ -406,7 +406,9 @@ module ActiveRecord
         synchronize do
           stale = Time.now - @dead_connection_timeout
           connections.dup.each do |conn|
-            remove conn if conn.in_use? && stale > conn.last_use && !conn.active?
+            if conn.in_use? && stale > conn.last_use && !conn.active?
+              remove conn
+            end
           end
         end
       end
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb b/activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb
index 2859fb31e8..c0a2111571 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/database_limits.rb
@@ -21,7 +21,7 @@ module ActiveRecord
       # limit is enforced by rails and Is less than or equal to
       # <tt>index_name_length</tt>. The gap between
       # <tt>index_name_length</tt> is to allow internal rails
-      # opreations to use prefixes in temporary opreations.
+      # operations to use prefixes in temporary operations.
       def allowed_index_name_length
         index_name_length
       end
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
index 42206de8fc..eb974e4a6e 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
@@ -8,37 +8,21 @@ module ActiveRecord
     # Abstract representation of an index definition on a table. Instances of
     # this type are typically created and returned by methods in database
     # adapters. e.g. ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter#indexes
-    class IndexDefinition < Struct.new(:table, :name, :unique, :columns, :lengths, :orders, :where) #:nodoc:
+    class IndexDefinition < Struct.new(:table, :name, :unique, :columns, :lengths, :orders, :where, :type, :using) #:nodoc:
     end
 
     # Abstract representation of a column definition. Instances of this type
     # are typically created by methods in TableDefinition, and added to the
     # +columns+ attribute of said TableDefinition object, in order to be used
     # for generating a number of table creation or table changing SQL statements.
-    class ColumnDefinition < Struct.new(:base, :name, :type, :limit, :precision, :scale, :default, :null) #:nodoc:
-
+    class ColumnDefinition < Struct.new(:name, :type, :limit, :precision, :scale, :default, :null, :first, :after, :primary_key) #:nodoc:
       def string_to_binary(value)
         value
       end
 
-      def sql_type
-        base.type_to_sql(type.to_sym, limit, precision, scale)
-      end
-
-      def to_sql
-        column_sql = "#{base.quote_column_name(name)} #{sql_type}"
-        column_options = {}
-        column_options[:null] = null unless null.nil?
-        column_options[:default] = default unless default.nil?
-        add_column_options!(column_sql, column_options) unless type.to_sym == :primary_key
-        column_sql
+      def primary_key?
+        primary_key || type.to_sym == :primary_key
       end
-
-      private
-
-        def add_column_options!(sql, options)
-          base.add_column_options!(sql, options.merge(:column => self))
-        end
     end
 
     # Represents the schema of an SQL table in an abstract way. This class
@@ -64,28 +48,25 @@ module ActiveRecord
     class TableDefinition
       # An array of ColumnDefinition objects, representing the column changes
       # that have been defined.
-      attr_accessor :columns, :indexes
+      attr_accessor :indexes
+      attr_reader :name, :temporary, :options
 
-      def initialize(base)
-        @columns = []
+      def initialize(types, name, temporary, options)
         @columns_hash = {}
         @indexes = {}
-        @base = base
+        @native = types
+        @temporary = temporary
+        @options = options
+        @name = name
       end
 
-      def xml(*args)
-        raise NotImplementedError unless %w{
-          sqlite mysql mysql2
-        }.include? @base.adapter_name.downcase
-
-        options = args.extract_options!
-        column(args[0], :text, options)
-      end
+      def columns; @columns_hash.values; end
 
       # Appends a primary key definition to the table definition.
       # Can be called multiple times, but this is probably not a good idea.
-      def primary_key(name)
-        column(name, :primary_key)
+      def primary_key(name, type = :primary_key, options = {})
+        options[:primary_key] = true
+        column(name, type, options)
       end
 
       # Returns a ColumnDefinition for the column with name +name+.
@@ -238,20 +219,14 @@ module ActiveRecord
           raise ArgumentError, "you can't redefine the primary key column '#{name}'. To define a custom primary key, pass { id: false } to create_table."
         end
 
-        column = self[name] || new_column_definition(@base, name, type)
-
-        limit = options.fetch(:limit) do
-          native[type][:limit] if native[type].is_a?(Hash)
-        end
-
-        column.limit     = limit
-        column.precision = options[:precision]
-        column.scale     = options[:scale]
-        column.default   = options[:default]
-        column.null      = options[:null]
+        @columns_hash[name] = new_column_definition(name, type, options)
         self
       end
 
+      def remove_column(name)
+        @columns_hash.delete name.to_s
+      end
+
       [:string, :text, :integer, :float, :decimal, :datetime, :timestamp, :time, :date, :binary, :boolean].each do |column_type|
         define_method column_type do |*args|
           options = args.extract_options!
@@ -288,28 +263,52 @@ module ActiveRecord
       end
       alias :belongs_to :references
 
-      # Returns a String whose contents are the column definitions
-      # concatenated together. This string can then be prepended and appended to
-      # to generate the final SQL to create the table.
-      def to_sql
-        @columns.map { |c| c.to_sql } * ', '
+      def new_column_definition(name, type, options) # :nodoc:
+        column = create_column_definition name, type
+        limit = options.fetch(:limit) do
+          native[type][:limit] if native[type].is_a?(Hash)
+        end
+
+        column.limit       = limit
+        column.precision   = options[:precision]
+        column.scale       = options[:scale]
+        column.default     = options[:default]
+        column.null        = options[:null]
+        column.first       = options[:first]
+        column.after       = options[:after]
+        column.primary_key = type == :primary_key || options[:primary_key]
+        column
       end
 
       private
-      def new_column_definition(base, name, type)
-        definition = ColumnDefinition.new base, name, type
-        @columns << definition
-        @columns_hash[name] = definition
-        definition
+      def create_column_definition(name, type)
+        ColumnDefinition.new name, type
       end
 
       def primary_key_column_name
-        primary_key_column = columns.detect { |c| c.type == :primary_key }
+        primary_key_column = columns.detect { |c| c.primary_key? }
         primary_key_column && primary_key_column.name
       end
 
       def native
-        @base.native_database_types
+        @native
+      end
+    end
+
+    class AlterTable # :nodoc:
+      attr_reader :adds
+
+      def initialize(td)
+        @td   = td
+        @adds = []
+      end
+
+      def name; @td.name; end
+
+      def add_column(name, type, options)
+        name = name.to_s
+        type = type.to_sym
+        @adds << @td.new_column_definition(name, type, options)
       end
     end
 
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb
index f587bf8140..cdf0cbe218 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb
@@ -5,7 +5,7 @@ module ActiveRecord
     # The goal of this module is to move Adapter specific column
     # definitions to the Adapter instead of having it in the schema
     # dumper itself. This code represents the normal case.
-    # We can then redefine how certain data types may be handled in the schema dumper on the 
+    # We can then redefine how certain data types may be handled in the schema dumper on the
     # Adapter level by over-writing this code inside the database specific adapters
     module ColumnDumper
       def column_spec(column, types)
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
index c1f3462bbe..aebcc2d874 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -5,7 +5,7 @@ module ActiveRecord
     module SchemaStatements
       include ActiveRecord::Migration::JoinTable
 
-      # Returns a Hash of mappings from the abstract data types to the native
+      # Returns a hash of mappings from the abstract data types to the native
       # database types. See TableDefinition#column for details on the recognized
       # abstract data types.
       def native_database_types
@@ -20,6 +20,7 @@ module ActiveRecord
       # Checks to see if the table +table_name+ exists on the database.
       #
       #   table_exists?(:developers)
+      #
       def table_exists?(table_name)
         tables.include?(table_name.to_s)
       end
@@ -29,17 +30,18 @@ module ActiveRecord
 
       # Checks to see if an index exists on a table for a given index definition.
       #
-      #  # Check an index exists
-      #  index_exists?(:suppliers, :company_id)
+      #   # Check an index exists
+      #   index_exists?(:suppliers, :company_id)
+      #
+      #   # Check an index on multiple columns exists
+      #   index_exists?(:suppliers, [:company_id, :company_type])
       #
-      #  # Check an index on multiple columns exists
-      #  index_exists?(:suppliers, [:company_id, :company_type])
+      #   # Check a unique index exists
+      #   index_exists?(:suppliers, :company_id, unique: true)
       #
-      #  # Check a unique index exists
-      #  index_exists?(:suppliers, :company_id, unique: true)
+      #   # Check an index with a custom name exists
+      #   index_exists?(:suppliers, :company_id, name: "idx_company_id"
       #
-      #  # Check an index with a custom name exists
-      #  index_exists?(:suppliers, :company_id, name: "idx_company_id")
       def index_exists?(table_name, column_name, options = {})
         column_names = Array(column_name)
         index_name = options.key?(:name) ? options[:name].to_s : index_name(table_name, :column => column_names)
@@ -56,17 +58,18 @@ module ActiveRecord
 
       # Checks to see if a column exists in a given table.
       #
-      #  # Check a column exists
-      #  column_exists?(:suppliers, :name)
+      #   # Check a column exists
+      #   column_exists?(:suppliers, :name)
       #
-      #  # Check a column exists of a particular type
-      #  column_exists?(:suppliers, :name, :string)
+      #   # Check a column exists of a particular type
+      #   column_exists?(:suppliers, :name, :string)
+      #
+      #   # Check a column exists with a specific definition
+      #   column_exists?(:suppliers, :name, :string, limit: 100)
+      #   column_exists?(:suppliers, :name, :string, default: 'default')
+      #   column_exists?(:suppliers, :name, :string, null: false)
+      #   column_exists?(:suppliers, :tax, :decimal, precision: 8, scale: 2)
       #
-      #  # Check a column exists with a specific definition
-      #  column_exists?(:suppliers, :name, :string, limit: 100)
-      #  column_exists?(:suppliers, :name, :string, default: 'default')
-      #  column_exists?(:suppliers, :name, :string, null: false)
-      #  column_exists?(:suppliers, :tax, :decimal, precision: 8, scale: 2)
       def column_exists?(table_name, column_name, type = nil, options = {})
         columns(table_name).any?{ |c| c.name == column_name.to_s &&
                                       (!type                     || c.type == type) &&
@@ -84,27 +87,30 @@ module ActiveRecord
       # form or the regular form, like this:
       #
       # === Block form
-      #  # create_table() passes a TableDefinition object to the block.
-      #  # This form will not only create the table, but also columns for the
-      #  # table.
       #
-      #  create_table(:suppliers) do |t|
-      #    t.column :name, :string, limit: 60
-      #    # Other fields here
-      #  end
+      #   # create_table() passes a TableDefinition object to the block.
+      #   # This form will not only create the table, but also columns for the
+      #   # table.
+      #
+      #   create_table(:suppliers) do |t|
+      #     t.column :name, :string, limit: 60
+      #     # Other fields here
+      #   end
       #
       # === Block form, with shorthand
-      #  # You can also use the column types as method calls, rather than calling the column method.
-      #  create_table(:suppliers) do |t|
-      #    t.string :name, limit: 60
-      #    # Other fields here
-      #  end
+      #
+      #   # You can also use the column types as method calls, rather than calling the column method.
+      #   create_table(:suppliers) do |t|
+      #     t.string :name, limit: 60
+      #     # Other fields here
+      #   end
       #
       # === Regular form
-      #  # Creates a table called 'suppliers' with no columns.
-      #  create_table(:suppliers)
-      #  # Add a column to 'suppliers'.
-      #  add_column(:suppliers, :name, :string, {limit: 60})
+      #
+      #   # Creates a table called 'suppliers' with no columns.
+      #   create_table(:suppliers)
+      #   # Add a column to 'suppliers'.
+      #   add_column(:suppliers, :name, :string, {limit: 60})
       #
       # The +options+ hash can include the following keys:
       # [<tt>:id</tt>]
@@ -127,37 +133,53 @@ module ActiveRecord
       #   Defaults to false.
       #
       # ====== Add a backend specific option to the generated SQL (MySQL)
-      #  create_table(:suppliers, options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8')
+      #
+      #   create_table(:suppliers, options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8')
+      #
       # generates:
-      #  CREATE TABLE suppliers (
-      #    id int(11) DEFAULT NULL auto_increment PRIMARY KEY
-      #  ) ENGINE=InnoDB DEFAULT CHARSET=utf8
+      #
+      #   CREATE TABLE suppliers (
+      #     id int(11) DEFAULT NULL auto_increment PRIMARY KEY
+      #   ) ENGINE=InnoDB DEFAULT CHARSET=utf8
       #
       # ====== Rename the primary key column
-      #  create_table(:objects, primary_key: 'guid') do |t|
-      #    t.column :name, :string, limit: 80
-      #  end
+      #
+      #   create_table(:objects, primary_key: 'guid') do |t|
+      #     t.column :name, :string, limit: 80
+      #   end
+      #
       # generates:
-      #  CREATE TABLE objects (
-      #    guid int(11) DEFAULT NULL auto_increment PRIMARY KEY,
-      #    name varchar(80)
-      #  )
+      #
+      #   CREATE TABLE objects (
+      #     guid int(11) DEFAULT NULL auto_increment PRIMARY KEY,
+      #     name varchar(80)
+      #   )
       #
       # ====== Do not add a primary key column
-      #  create_table(:categories_suppliers, id: false) do |t|
-      #    t.column :category_id, :integer
-      #    t.column :supplier_id, :integer
-      #  end
+      #
+      #   create_table(:categories_suppliers, id: false) do |t|
+      #     t.column :category_id, :integer
+      #     t.column :supplier_id, :integer
+      #   end
+      #
       # generates:
-      #  CREATE TABLE categories_suppliers (
-      #    category_id int,
-      #    supplier_id int
-      #  )
+      #
+      #   CREATE TABLE categories_suppliers (
+      #     category_id int,
+      #     supplier_id int
+      #   )
       #
       # See also TableDefinition#column for details on how to create columns.
       def create_table(table_name, options = {})
-        td = create_table_definition
-        td.primary_key(options[:primary_key] || Base.get_primary_key(table_name.to_s.singularize)) unless options[:id] == false
+        td = create_table_definition table_name, options[:temporary], options[:options]
+
+        unless options[:id] == false
+          pk = options.fetch(:primary_key) {
+            Base.get_primary_key table_name.to_s.singularize
+          }
+
+          td.primary_key pk, options.fetch(:id, :primary_key), options
+        end
 
         yield td if block_given?
 
@@ -165,19 +187,15 @@ module ActiveRecord
           drop_table(table_name, options)
         end
 
-        create_sql = "CREATE#{' TEMPORARY' if options[:temporary]} TABLE "
-        create_sql << "#{quote_table_name(table_name)} ("
-        create_sql << td.to_sql
-        create_sql << ") #{options[:options]}"
-        execute create_sql
+        execute schema_creation.accept td
         td.indexes.each_pair { |c,o| add_index table_name, c, o }
       end
 
       # Creates a new join table with the name created using the lexical order of the first two
       # arguments. These arguments can be a String or a Symbol.
       #
-      #  # Creates a table called 'assemblies_parts' with no id.
-      #  create_join_table(:assemblies, :parts)
+      #   # Creates a table called 'assemblies_parts' with no id.
+      #   create_join_table(:assemblies, :parts)
       #
       # You can pass a +options+ hash can include the following keys:
       # [<tt>:table_name</tt>]
@@ -201,12 +219,16 @@ module ActiveRecord
       #   end
       #
       # ====== Add a backend specific option to the generated SQL (MySQL)
-      #  create_join_table(:assemblies, :parts, options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8')
+      #
+      #   create_join_table(:assemblies, :parts, options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8')
+      #
       # generates:
-      #  CREATE TABLE assemblies_parts (
-      #    assembly_id int NOT NULL,
-      #    part_id int NOT NULL,
-      #  ) ENGINE=InnoDB DEFAULT CHARSET=utf8
+      #
+      #   CREATE TABLE assemblies_parts (
+      #     assembly_id int NOT NULL,
+      #     part_id int NOT NULL,
+      #   ) ENGINE=InnoDB DEFAULT CHARSET=utf8
+      #
       def create_join_table(table_1, table_2, options = {})
         join_table_name = find_join_table_name(table_1, table_2, options)
 
@@ -223,7 +245,7 @@ module ActiveRecord
       end
 
       # Drops the join table specified by the given arguments.
-      # See create_join_table for details.
+      # See +create_join_table+ for details.
       #
       # Although this command ignores the block if one is given, it can be helpful
       # to provide one in a migration's +change+ method so it can be reverted.
@@ -235,66 +257,74 @@ module ActiveRecord
 
       # A block for changing columns in +table+.
       #
-      #  # change_table() yields a Table instance
-      #  change_table(:suppliers) do |t|
-      #    t.column :name, :string, limit: 60
-      #    # Other column alterations here
-      #  end
+      #   # change_table() yields a Table instance
+      #   change_table(:suppliers) do |t|
+      #     t.column :name, :string, limit: 60
+      #     # Other column alterations here
+      #   end
       #
       # The +options+ hash can include the following keys:
       # [<tt>:bulk</tt>]
       #   Set this to true to make this a bulk alter query, such as
-      #   ALTER TABLE `users` ADD COLUMN age INT(11), ADD COLUMN birthdate DATETIME ...
+      #
+      #     ALTER TABLE `users` ADD COLUMN age INT(11), ADD COLUMN birthdate DATETIME ...
       #
       #   Defaults to false.
       #
       # ====== Add a column
-      #  change_table(:suppliers) do |t|
-      #    t.column :name, :string, limit: 60
-      #  end
+      #
+      #   change_table(:suppliers) do |t|
+      #     t.column :name, :string, limit: 60
+      #   end
       #
       # ====== Add 2 integer columns
-      #  change_table(:suppliers) do |t|
-      #    t.integer :width, :height, null: false, default: 0
-      #  end
+      #
+      #   change_table(:suppliers) do |t|
+      #     t.integer :width, :height, null: false, default: 0
+      #   end
       #
       # ====== Add created_at/updated_at columns
-      #  change_table(:suppliers) do |t|
-      #    t.timestamps
-      #  end
+      #
+      #   change_table(:suppliers) do |t|
+      #     t.timestamps
+      #   end
       #
       # ====== Add a foreign key column
-      #  change_table(:suppliers) do |t|
-      #    t.references :company
-      #  end
       #
-      # Creates a <tt>company_id(integer)</tt> column
+      #   change_table(:suppliers) do |t|
+      #     t.references :company
+      #   end
+      #
+      # Creates a <tt>company_id(integer)</tt> column.
       #
       # ====== Add a polymorphic foreign key column
+      #
       #  change_table(:suppliers) do |t|
       #    t.belongs_to :company, polymorphic: true
       #  end
       #
-      # Creates <tt>company_type(varchar)</tt> and <tt>company_id(integer)</tt> columns
+      # Creates <tt>company_type(varchar)</tt> and <tt>company_id(integer)</tt> columns.
       #
       # ====== Remove a column
+      #
       #  change_table(:suppliers) do |t|
       #    t.remove :company
       #  end
       #
       # ====== Remove several columns
+      #
       #  change_table(:suppliers) do |t|
       #    t.remove :company_id
       #    t.remove :width, :height
       #  end
       #
       # ====== Remove an index
+      #
       #  change_table(:suppliers) do |t|
       #    t.remove_index :company_id
       #  end
       #
-      # See also Table for details on
-      # all of the various column transformation
+      # See also Table for details on all of the various column transformation.
       def change_table(table_name, options = {})
         if supports_bulk_alter? && options[:bulk]
           recorder = ActiveRecord::Migration::CommandRecorder.new(self)
@@ -307,7 +337,8 @@ module ActiveRecord
 
       # Renames a table.
       #
-      #  rename_table('octopuses', 'octopi')
+      #   rename_table('octopuses', 'octopi')
+      #
       def rename_table(table_name, new_name)
         raise NotImplementedError, "rename_table is not implemented"
       end
@@ -324,14 +355,15 @@ module ActiveRecord
       # Adds a new column to the named table.
       # See TableDefinition#column for details of the options you can use.
       def add_column(table_name, column_name, type, options = {})
-        add_column_sql = "ALTER TABLE #{quote_table_name(table_name)} ADD #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"
-        add_column_options!(add_column_sql, options)
-        execute(add_column_sql)
+        at = create_alter_table table_name
+        at.add_column(column_name, type, options)
+        execute schema_creation.accept at
       end
 
       # Removes the given columns from the table definition.
       #
-      #  remove_columns(:suppliers, :qualification, :experience)
+      #   remove_columns(:suppliers, :qualification, :experience)
+      #
       def remove_columns(table_name, *column_names)
         raise ArgumentError.new("You must specify at least one column name. Example: remove_columns(:people, :first_name)") if column_names.empty?
         column_names.each do |column_name|
@@ -341,7 +373,7 @@ module ActiveRecord
 
       # Removes the column from the table definition.
       #
-      #  remove_column(:suppliers, :qualification)
+      #   remove_column(:suppliers, :qualification)
       #
       # The +type+ and +options+ parameters will be ignored if present. It can be helpful
       # to provide these in a migration's +change+ method so it can be reverted.
@@ -353,24 +385,50 @@ module ActiveRecord
       # Changes the column's definition according to the new options.
       # See TableDefinition#column for details of the options you can use.
       #
-      #  change_column(:suppliers, :name, :string, limit: 80)
-      #  change_column(:accounts, :description, :text)
+      #   change_column(:suppliers, :name, :string, limit: 80)
+      #   change_column(:accounts, :description, :text)
+      #
       def change_column(table_name, column_name, type, options = {})
         raise NotImplementedError, "change_column is not implemented"
       end
 
-      # Sets a new default value for a column.
+      # Sets a new default value for a column:
+      #
+      #   change_column_default(:suppliers, :qualification, 'new')
+      #   change_column_default(:accounts, :authorized, 1)
+      #
+      # Setting the default to +nil+ effectively drops the default:
+      #
+      #   change_column_default(:users, :email, nil)
       #
-      #  change_column_default(:suppliers, :qualification, 'new')
-      #  change_column_default(:accounts, :authorized, 1)
-      #  change_column_default(:users, :email, nil)
       def change_column_default(table_name, column_name, default)
         raise NotImplementedError, "change_column_default is not implemented"
       end
 
+      # Sets or removes a +NOT NULL+ constraint on a column. The +null+ flag
+      # indicates whether the value can be +NULL+. For example
+      #
+      #   change_column_null(:users, :nickname, false)
+      #
+      # says nicknames cannot be +NULL+ (adds the constraint), whereas
+      #
+      #   change_column_null(:users, :nickname, true)
+      #
+      # allows them to be +NULL+ (drops the constraint).
+      #
+      # The method accepts an optional fourth argument to replace existing
+      # +NULL+s with some other value. Use that one when enabling the
+      # constraint if needed, since otherwise those rows would not be valid.
+      #
+      # Please note the fourth argument does not set a column's default.
+      def change_column_null(table_name, column_name, null, default = nil)
+        raise NotImplementedError, "change_column_null is not implemented"
+      end
+
       # Renames a column.
       #
-      #  rename_column(:suppliers, :description, :name)
+      #   rename_column(:suppliers, :description, :name)
+      #
       def rename_column(table_name, column_name, new_column_name)
         raise NotImplementedError, "rename_column is not implemented"
       end
@@ -382,60 +440,106 @@ module ActiveRecord
       # you pass <tt>:name</tt> as an option.
       #
       # ====== Creating a simple index
-      #  add_index(:suppliers, :name)
+      #
+      #   add_index(:suppliers, :name)
+      #
       # generates
-      #  CREATE INDEX suppliers_name_index ON suppliers(name)
+      #
+      #   CREATE INDEX suppliers_name_index ON suppliers(name)
       #
       # ====== Creating a unique index
-      #  add_index(:accounts, [:branch_id, :party_id], unique: true)
+      #
+      #   add_index(:accounts, [:branch_id, :party_id], unique: true)
+      #
       # generates
-      #  CREATE UNIQUE INDEX accounts_branch_id_party_id_index ON accounts(branch_id, party_id)
+      #
+      #   CREATE UNIQUE INDEX accounts_branch_id_party_id_index ON accounts(branch_id, party_id)
       #
       # ====== Creating a named index
-      #  add_index(:accounts, [:branch_id, :party_id], unique: true, name: 'by_branch_party')
+      #
+      #   add_index(:accounts, [:branch_id, :party_id], unique: true, name: 'by_branch_party')
+      #
       # generates
+      #
       #  CREATE UNIQUE INDEX by_branch_party ON accounts(branch_id, party_id)
       #
       # ====== Creating an index with specific key length
-      #  add_index(:accounts, :name, name: 'by_name', length: 10)
+      #
+      #   add_index(:accounts, :name, name: 'by_name', length: 10)
+      #
       # generates
-      #  CREATE INDEX by_name ON accounts(name(10))
       #
-      #  add_index(:accounts, [:name, :surname], name: 'by_name_surname', length: {name: 10, surname: 15})
+      #   CREATE INDEX by_name ON accounts(name(10))
+      #
+      #   add_index(:accounts, [:name, :surname], name: 'by_name_surname', length: {name: 10, surname: 15})
+      #
       # generates
-      #  CREATE INDEX by_name_surname ON accounts(name(10), surname(15))
       #
-      # Note: SQLite doesn't support index length
+      #   CREATE INDEX by_name_surname ON accounts(name(10), surname(15))
+      #
+      # Note: SQLite doesn't support index length.
       #
       # ====== Creating an index with a sort order (desc or asc, asc is the default)
-      #  add_index(:accounts, [:branch_id, :party_id, :surname], order: {branch_id: :desc, party_id: :asc})
+      #
+      #   add_index(:accounts, [:branch_id, :party_id, :surname], order: {branch_id: :desc, party_id: :asc})
+      #
       # generates
-      #  CREATE INDEX by_branch_desc_party ON accounts(branch_id DESC, party_id ASC, surname)
       #
-      # Note: mysql doesn't yet support index order (it accepts the syntax but ignores it)
+      #   CREATE INDEX by_branch_desc_party ON accounts(branch_id DESC, party_id ASC, surname)
+      #
+      # Note: MySQL doesn't yet support index order (it accepts the syntax but ignores it).
       #
       # ====== Creating a partial index
-      #  add_index(:accounts, [:branch_id, :party_id], unique: true, where: "active")
+      #
+      #   add_index(:accounts, [:branch_id, :party_id], unique: true, where: "active")
+      #
+      # generates
+      #
+      #   CREATE UNIQUE INDEX index_accounts_on_branch_id_and_party_id ON accounts(branch_id, party_id) WHERE active
+      #
+      # ====== Creating an index with a specific method
+      #
+      #  add_index(:developers, :name, :using => 'btree')
+      #
       # generates
-      #  CREATE UNIQUE INDEX index_accounts_on_branch_id_and_party_id ON accounts(branch_id, party_id) WHERE active
       #
-      # Note: only supported by PostgreSQL
+      #  CREATE INDEX index_developers_on_name ON developers USING btree (name) -- PostgreSQL
+      #  CREATE INDEX index_developers_on_name USING btree ON developers (name) -- MySQL
       #
+      # Note: only supported by PostgreSQL and MySQL
+      #
+      # ====== Creating an index with a specific type
+      #
+      #   add_index(:developers, :name, :type => :fulltext)
+      #
+      # generates
+      #
+      #   CREATE FULLTEXT INDEX index_developers_on_name ON developers (name) -- MySQL
+      #
+      # Note: only supported by MySQL. Supported: <tt>:fulltext</tt> and <tt>:spatial</tt> on MyISAM tables.
       def add_index(table_name, column_name, options = {})
         index_name, index_type, index_columns, index_options = add_index_options(table_name, column_name, options)
         execute "CREATE #{index_type} INDEX #{quote_column_name(index_name)} ON #{quote_table_name(table_name)} (#{index_columns})#{index_options}"
       end
 
-      # Remove the given index from the table.
+      # Removes the given index from the table.
+      #
+      # Removes the +index_accounts_on_column+ in the +accounts+ table.
       #
-      # Remove the index_accounts_on_column in the accounts table.
       #   remove_index :accounts, :column
-      # Remove the index named index_accounts_on_branch_id in the accounts table.
+      #
+      # Removes the index named +index_accounts_on_branch_id+ in the +accounts+ table.
+      #
       #   remove_index :accounts, column: :branch_id
-      # Remove the index named index_accounts_on_branch_id_and_party_id in the accounts table.
+      #
+      # Removes the index named +index_accounts_on_branch_id_and_party_id+ in the +accounts+ table.
+      #
       #   remove_index :accounts, column: [:branch_id, :party_id]
-      # Remove the index named by_branch_party in the accounts table.
+      #
+      # Removes the index named +by_branch_party+ in the +accounts+ table.
+      #
       #   remove_index :accounts, name: :by_branch_party
+      #
       def remove_index(table_name, options = {})
         remove_index!(table_name, index_name_for_remove(table_name, options))
       end
@@ -444,10 +548,12 @@ module ActiveRecord
         execute "DROP INDEX #{quote_column_name(index_name)} ON #{quote_table_name(table_name)}"
       end
 
-      # Rename an index.
+      # Renames an index.
+      #
+      # Rename the +index_people_on_last_name+ index to +index_users_on_last_name+:
       #
-      # Rename the index_people_on_last_name index to index_users_on_last_name
       #   rename_index :people, 'index_people_on_last_name', 'index_users_on_last_name'
+      #
       def rename_index(table_name, old_name, new_name)
         # this is a naive implementation; some DBs may support this more efficiently (Postgres, for instance)
         old_index_def = indexes(table_name).detect { |i| i.name == old_name }
@@ -470,7 +576,7 @@ module ActiveRecord
         end
       end
 
-      # Verify the existence of an index with a given name.
+      # Verifies the existence of an index with a given name.
       #
       # The default argument is returned if the underlying implementation does not define the indexes method,
       # as there's no way to determine the correct answer in that case.
@@ -484,13 +590,16 @@ module ActiveRecord
       # <tt>add_reference</tt> and <tt>add_belongs_to</tt> are acceptable.
       #
       # ====== Create a user_id column
-      #  add_reference(:products, :user)
+      #
+      #   add_reference(:products, :user)
       #
       # ====== Create a supplier_id and supplier_type columns
-      #  add_belongs_to(:products, :supplier, polymorphic: true)
+      #
+      #   add_belongs_to(:products, :supplier, polymorphic: true)
       #
       # ====== Create a supplier_id, supplier_type columns and appropriate index
-      #  add_reference(:products, :supplier, polymorphic: true, index: true)
+      #
+      #   add_reference(:products, :supplier, polymorphic: true, index: true)
       #
       def add_reference(table_name, ref_name, options = {})
         polymorphic = options.delete(:polymorphic)
@@ -505,10 +614,12 @@ module ActiveRecord
       # <tt>remove_reference</tt>, <tt>remove_references</tt> and <tt>remove_belongs_to</tt> are acceptable.
       #
       # ====== Remove the reference
-      #  remove_reference(:products, :user, index: true)
+      #
+      #   remove_reference(:products, :user, index: true)
       #
       # ====== Remove polymorphic reference
-      #  remove_reference(:products, :supplier, polymorphic: true)
+      #
+      #   remove_reference(:products, :supplier, polymorphic: true)
       #
       def remove_reference(table_name, ref_name, options = {})
         remove_column(table_name, "#{ref_name}_id")
@@ -589,27 +700,33 @@ module ActiveRecord
         if options[:null] == false
           sql << " NOT NULL"
         end
+        if options[:auto_increment] == true
+          sql << " AUTO_INCREMENT"
+        end
       end
 
       # SELECT DISTINCT clause for a given set of columns and a given ORDER BY clause.
       # Both PostgreSQL and Oracle overrides this for custom DISTINCT syntax.
       #
       #   distinct("posts.id", "posts.created_at desc")
+      #
       def distinct(columns, order_by)
         "DISTINCT #{columns}"
       end
 
-      # Adds timestamps (created_at and updated_at) columns to the named table.
+      # Adds timestamps (+created_at+ and +updated_at+) columns to the named table.
+      #
+      #   add_timestamps(:suppliers)
       #
-      #  add_timestamps(:suppliers)
       def add_timestamps(table_name)
         add_column table_name, :created_at, :datetime
         add_column table_name, :updated_at, :datetime
       end
 
-      # Removes the timestamp columns (created_at and updated_at) from the table definition.
+      # Removes the timestamp columns (+created_at+ and +updated_at+) from the table definition.
       #
       #  remove_timestamps(:suppliers)
+      #
       def remove_timestamps(table_name)
         remove_column table_name, :updated_at
         remove_column table_name, :created_at
@@ -650,12 +767,21 @@ module ActiveRecord
           index_name   = index_name(table_name, column: column_names)
 
           if Hash === options # legacy support, since this param was a string
-            options.assert_valid_keys(:unique, :order, :name, :where, :length, :internal)
+            options.assert_valid_keys(:unique, :order, :name, :where, :length, :internal, :using, :algorithm, :type)
 
             index_type = options[:unique] ? "UNIQUE" : ""
+            index_type = options[:type].to_s if options.key?(:type)
             index_name = options[:name].to_s if options.key?(:name)
             max_index_length = options.fetch(:internal, false) ? index_name_length : allowed_index_name_length
 
+            if index_algorithms.key?(options[:algorithm])
+              algorithm = index_algorithms[options[:algorithm]]
+            elsif options[:algorithm].present?
+              raise ArgumentError.new("Algorithm must be one of the following: #{index_algorithms.keys.map(&:inspect).join(', ')}")
+            end
+
+            using = "USING #{options[:using]}" if options[:using].present?
+
             if supports_partial_index?
               index_options = options[:where] ? " WHERE #{options[:where]}" : ""
             end
@@ -670,6 +796,7 @@ module ActiveRecord
 
             index_type = options
             max_index_length = allowed_index_name_length
+            algorithm = using = nil
           end
 
           if index_name.length > max_index_length
@@ -680,7 +807,7 @@ module ActiveRecord
           end
           index_columns = quoted_columns_for_index(column_names, options).join(", ")
 
-          [index_name, index_type, index_columns, index_options]
+          [index_name, index_type, index_columns, index_options, algorithm, using]
         end
 
         def index_name_for_remove(table_name, options = {})
@@ -730,8 +857,12 @@ module ActiveRecord
         end
 
       private
-      def create_table_definition
-        TableDefinition.new(self)
+      def create_table_definition(name, temporary, options)
+        TableDefinition.new native_database_types, name, temporary, options
+      end
+
+      def create_alter_table(name)
+        AlterTable.new create_table_definition(name, false, {})
       end
 
       def update_table_definition(table_name, base)
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/transaction.rb b/activerecord/lib/active_record/connection_adapters/abstract/transaction.rb
index 73c80a3220..2b6685499a 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/transaction.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/transaction.rb
@@ -78,7 +78,7 @@ module ActiveRecord
         @joinable  = options.fetch(:joinable, true)
       end
 
-      # This state is necesarry so that we correctly handle stuff that might
+      # This state is necessary so that we correctly handle stuff that might
       # happen in a commit/rollback. But it's kinda distasteful. Maybe we can
       # find a better way to structure it in the future.
       def finishing?
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index 7949bcb5ce..2ccde15a26 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -18,6 +18,7 @@ module ActiveRecord
       autoload :ColumnDefinition
       autoload :TableDefinition
       autoload :Table
+      autoload :AlterTable
     end
 
     autoload_at 'active_record/connection_adapters/abstract/connection_pool' do
@@ -100,6 +101,79 @@ module ActiveRecord
         @visitor             = nil
       end
 
+      def valid_type?(type)
+        true
+      end
+
+      class SchemaCreation
+        def initialize(conn)
+          @conn  = conn
+          @cache = {}
+        end
+
+        def accept(o)
+          m = @cache[o.class] ||= "visit_#{o.class.name.split('::').last}"
+          send m, o
+        end
+
+        private
+
+        def visit_AlterTable(o)
+          sql = "ALTER TABLE #{quote_table_name(o.name)} "
+          sql << o.adds.map { |col| visit_AddColumn col }.join(' ')
+        end
+
+        def visit_AddColumn(o)
+          sql_type = type_to_sql(o.type.to_sym, o.limit, o.precision, o.scale)
+          sql = "ADD #{quote_column_name(o.name)} #{sql_type}"
+          add_column_options!(sql, column_options(o))
+        end
+
+        def visit_ColumnDefinition(o)
+          sql_type = type_to_sql(o.type.to_sym, o.limit, o.precision, o.scale)
+          column_sql = "#{quote_column_name(o.name)} #{sql_type}"
+          add_column_options!(column_sql, column_options(o)) unless o.primary_key?
+          column_sql
+        end
+
+        def visit_TableDefinition(o)
+          create_sql = "CREATE#{' TEMPORARY' if o.temporary} TABLE "
+          create_sql << "#{quote_table_name(o.name)} ("
+          create_sql << o.columns.map { |c| accept c }.join(', ')
+          create_sql << ") #{o.options}"
+          create_sql
+        end
+
+        def column_options(o)
+          column_options = {}
+          column_options[:null] = o.null unless o.null.nil?
+          column_options[:default] = o.default unless o.default.nil?
+          column_options[:column] = o
+          column_options
+        end
+
+        def quote_column_name(name)
+          @conn.quote_column_name name
+        end
+
+        def quote_table_name(name)
+          @conn.quote_table_name name
+        end
+
+        def type_to_sql(type, limit, precision, scale)
+          @conn.type_to_sql type.to_sym, limit, precision, scale
+        end
+
+        def add_column_options!(column_sql, column_options)
+          @conn.add_column_options! column_sql, column_options
+          column_sql
+        end
+      end
+
+      def schema_creation
+        SchemaCreation.new self
+      end
+
       def lease
         synchronize do
           unless in_use
@@ -212,6 +286,13 @@ module ActiveRecord
         []
       end
 
+      # A list of index algorithms, to be filled by adapters that
+      # support them. MySQL and PostgreSQL has support for them right
+      # now.
+      def index_algorithms
+        {}
+      end
+
       # QUOTING ==================================================
 
       # Returns a bind substitution value given a +column+ and list of current
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
index f88f5742a8..b0b160f9b4 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
@@ -3,13 +3,34 @@ require 'arel/visitors/bind_visitor'
 module ActiveRecord
   module ConnectionAdapters
     class AbstractMysqlAdapter < AbstractAdapter
+      class SchemaCreation < AbstractAdapter::SchemaCreation
+        private
+
+        def visit_AddColumn(o)
+          add_column_position!(super, o)
+        end
+
+        def add_column_position!(sql, column)
+          if column.first
+            sql << " FIRST"
+          elsif column.after
+            sql << " AFTER #{quote_column_name(column.after)}"
+          end
+          sql
+        end
+      end
+
+      def schema_creation
+        SchemaCreation.new self
+      end
+
       class Column < ConnectionAdapters::Column # :nodoc:
-        attr_reader :collation, :strict
+        attr_reader :collation, :strict, :extra
 
-        def initialize(name, default, sql_type = nil, null = true, collation = nil, strict = false)
+        def initialize(name, default, sql_type = nil, null = true, collation = nil, strict = false, extra = "")
           @strict    = strict
           @collation = collation
-
+          @extra     = extra
           super(name, default, sql_type, null)
         end
 
@@ -130,6 +151,9 @@ module ActiveRecord
         :boolean     => { :name => "tinyint", :limit => 1 }
       }
 
+      INDEX_TYPES  = [:fulltext, :spatial]
+      INDEX_USINGS = [:btree, :hash]
+
       class BindSubstitution < Arel::Visitors::MySQL # :nodoc:
         include Arel::Visitors::BindVisitor
       end
@@ -187,6 +211,10 @@ module ActiveRecord
         NATIVE_DATABASE_TYPES
       end
 
+      def index_algorithms
+        { default: 'ALGORITHM = DEFAULT', copy: 'ALGORITHM = COPY', inplace: 'ALGORITHM = INPLACE' }
+      end
+
       # HELPER METHODS ===========================================
 
       # The two drivers have slightly different ways of yielding hashes of results, so
@@ -196,8 +224,8 @@ module ActiveRecord
       end
 
       # Overridden by the adapters to instantiate their specific Column type.
-      def new_column(field, default, type, null, collation) # :nodoc:
-        Column.new(field, default, type, null, collation)
+      def new_column(field, default, type, null, collation, extra = "") # :nodoc:
+        Column.new(field, default, type, null, collation, extra)
       end
 
       # Must return the Mysql error number from the exception, if the exception has an
@@ -410,7 +438,11 @@ module ActiveRecord
             if current_index != row[:Key_name]
               next if row[:Key_name] == 'PRIMARY' # skip the primary key
               current_index = row[:Key_name]
-              indexes << IndexDefinition.new(row[:Table], row[:Key_name], row[:Non_unique].to_i == 0, [], [])
+
+              mysql_index_type = row[:Index_type].downcase.to_sym
+              index_type  = INDEX_TYPES.include?(mysql_index_type)  ? mysql_index_type : nil
+              index_using = INDEX_USINGS.include?(mysql_index_type) ? mysql_index_type : nil
+              indexes << IndexDefinition.new(row[:Table], row[:Key_name], row[:Non_unique].to_i == 0, [], [], nil, nil, index_type, index_using)
             end
 
             indexes.last.columns << row[:Column_name]
@@ -426,7 +458,7 @@ module ActiveRecord
         sql = "SHOW FULL FIELDS FROM #{quote_table_name(table_name)}"
         execute_and_free(sql, 'SCHEMA') do |result|
           each_hash(result).map do |field|
-            new_column(field[:Field], field[:Default], field[:Type], field[:Null] == "YES", field[:Collation])
+            new_column(field[:Field], field[:Default], field[:Type], field[:Null] == "YES", field[:Collation], field[:Extra])
           end
         end
       end
@@ -459,10 +491,6 @@ module ActiveRecord
         rename_table_indexes(table_name, new_name)
       end
 
-      def add_column(table_name, column_name, type, options = {})
-        execute("ALTER TABLE #{quote_table_name(table_name)} #{add_column_sql(table_name, column_name, type, options)}")
-      end
-
       def change_column_default(table_name, column_name, default)
         column = column_for(table_name, column_name)
         change_column table_name, column_name, column.sql_type, :default => default
@@ -487,6 +515,11 @@ module ActiveRecord
         rename_column_indexes(table_name, column_name, new_column_name)
       end
 
+      def add_index(table_name, column_name, options = {}) #:nodoc:
+        index_name, index_type, index_columns, index_options, index_algorithm, index_using = add_index_options(table_name, column_name, options)
+        execute "CREATE #{index_type} INDEX #{quote_column_name(index_name)} #{index_using} ON #{quote_table_name(table_name)} (#{index_columns})#{index_options} #{index_algorithm}"
+      end
+
       # Maps logical Rails types to MySQL-specific data types.
       def type_to_sql(type, limit = nil, precision = nil, scale = nil)
         case type.to_s
@@ -572,6 +605,10 @@ module ActiveRecord
         self.class.type_cast_config_to_boolean(@config.fetch(:strict, true))
       end
 
+      def valid_type?(type)
+        !native_database_types[type].nil?
+      end
+
       protected
 
       # MySQL is too stupid to create a temporary table for use subquery, so we have
@@ -651,6 +688,7 @@ module ActiveRecord
         if column = columns(table_name).find { |c| c.name == column_name.to_s }
           options[:default] = column.default
           options[:null] = column.null
+          options[:auto_increment] = (column.extra == "auto_increment")
         else
           raise ActiveRecordError, "No such column: #{table_name}.#{column_name}"
         end
diff --git a/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
index 99ea1ee0ca..530a27d099 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
@@ -38,6 +38,15 @@ module ActiveRecord
         configure_connection
       end
 
+      MAX_INDEX_LENGTH_FOR_UTF8MB4 = 191
+      def initialize_schema_migrations_table
+        if @config[:encoding] == 'utf8mb4'
+          ActiveRecord::SchemaMigration.create_table(MAX_INDEX_LENGTH_FOR_UTF8MB4)
+        else
+          ActiveRecord::SchemaMigration.create_table
+        end
+      end
+
       def supports_explain?
         true
       end
@@ -54,8 +63,8 @@ module ActiveRecord
         end
       end
 
-      def new_column(field, default, type, null, collation) # :nodoc:
-        Column.new(field, default, type, null, collation, strict_mode?)
+      def new_column(field, default, type, null, collation, extra = "") # :nodoc:
+        Column.new(field, default, type, null, collation, strict_mode?, extra)
       end
 
       def error_number(exception)
diff --git a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
index c836c5d8e8..09ba2e0d4a 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
@@ -150,8 +150,8 @@ module ActiveRecord
         end
       end
 
-      def new_column(field, default, type, null, collation) # :nodoc:
-        Column.new(field, default, type, null, collation, strict_mode?)
+      def new_column(field, default, type, null, collation, extra = "") # :nodoc:
+        Column.new(field, default, type, null, collation, strict_mode?, extra)
       end
 
       def error_number(exception) # :nodoc:
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/cast.rb b/activerecord/lib/active_record/connection_adapters/postgresql/cast.rb
index 3d8f0b575c..14ef07a75e 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/cast.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/cast.rb
@@ -2,6 +2,17 @@ module ActiveRecord
   module ConnectionAdapters
     class PostgreSQLColumn < Column
       module Cast
+        def point_to_string(point)
+          "(#{point[0]},#{point[1]})"
+        end
+
+        def string_to_point(string)
+          if string[0] == '(' && string[-1] == ')'
+            string = string[1...-1]
+          end
+          string.split(',').map{ |v| Float(v) }
+        end
+
         def string_to_time(string)
           return string unless String === string
 
@@ -30,8 +41,8 @@ module ActiveRecord
             nil
           elsif String === string
             Hash[string.scan(HstorePair).map { |k,v|
-              v = v.upcase == 'NULL' ? nil : v.gsub(/^"(.*)"$/,'\1').gsub(/\\(.)/, '\1')
-              k = k.gsub(/^"(.*)"$/,'\1').gsub(/\\(.)/, '\1')
+              v = v.upcase == 'NULL' ? nil : v.gsub(/\A"(.*)"\Z/m,'\1').gsub(/\\(.)/, '\1')
+              k = k.gsub(/\A"(.*)"\Z/m,'\1').gsub(/\\(.)/, '\1')
               [k,v]
             }]
           else
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb
index 68f2f2ca7b..51f377dfd7 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb
@@ -63,6 +63,16 @@ module ActiveRecord
           end
         end
 
+        class Point < Type
+          def type_cast(value)
+            if String === value
+              ConnectionAdapters::PostgreSQLColumn.string_to_point value
+            else
+              value
+            end
+          end
+        end
+
         class Array < Type
           attr_reader :subtype
           def initialize(subtype)
@@ -330,6 +340,7 @@ module ActiveRecord
         register_type 'time', OID::Time.new
 
         register_type 'path', OID::Identity.new
+        register_type 'point', OID::Point.new
         register_type 'polygon', OID::Identity.new
         register_type 'circle', OID::Identity.new
         register_type 'hstore', OID::Hstore.new
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/quoting.rb b/activerecord/lib/active_record/connection_adapters/postgresql/quoting.rb
index 47e2e3928f..6329733abc 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/quoting.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/quoting.rb
@@ -18,27 +18,33 @@ module ActiveRecord
         def quote(value, column = nil) #:nodoc:
           return super unless column
 
+          sql_type = type_to_sql(column.type, column.limit, column.precision, column.scale)
+
           case value
           when Range
-            if /range$/ =~ column.sql_type
-              "'#{PostgreSQLColumn.range_to_string(value)}'::#{column.sql_type}"
+            if /range$/ =~ sql_type
+              "'#{PostgreSQLColumn.range_to_string(value)}'::#{sql_type}"
             else
               super
             end
           when Array
-            if column.array
-              "'#{PostgreSQLColumn.array_to_string(value, column, self)}'"
+            case sql_type
+            when 'point' then super(PostgreSQLColumn.point_to_string(value))
             else
-              super
+              if column.array
+                "'#{PostgreSQLColumn.array_to_string(value, column, self)}'"
+              else
+                super
+              end
             end
           when Hash
-            case column.sql_type
+            case sql_type
             when 'hstore' then super(PostgreSQLColumn.hstore_to_string(value), column)
             when 'json' then super(PostgreSQLColumn.json_to_string(value), column)
             else super
             end
           when IPAddr
-            case column.sql_type
+            case sql_type
             when 'inet', 'cidr' then super(PostgreSQLColumn.cidr_to_string(value), column)
             else super
             end
@@ -51,11 +57,14 @@ module ActiveRecord
               super
             end
           when Numeric
-            return super unless column.sql_type == 'money'
-            # Not truly string input, so doesn't require (or allow) escape string syntax.
-            "'#{value}'"
+            if sql_type == 'money' || [:string, :text].include?(column.type)
+              # Not truly string input, so doesn't require (or allow) escape string syntax.
+              "'#{value}'"
+            else
+              super
+            end
           when String
-            case column.sql_type
+            case sql_type
             when 'bytea' then "'#{escape_bytea(value)}'"
             when 'xml'   then "xml '#{quote_string(value)}'"
             when /^bit/
@@ -87,8 +96,12 @@ module ActiveRecord
               super(value, column)
             end
           when Array
-            return super(value, column) unless column.array
-            PostgreSQLColumn.array_to_string(value, column, self)
+            case column.sql_type
+            when 'point' then PostgreSQLColumn.point_to_string(value)
+            else
+              return super(value, column) unless column.array
+              PostgreSQLColumn.array_to_string(value, column, self)
+            end
           when String
             return super(value, column) unless 'bytea' == column.sql_type
             { :value => value, :format => 1 }
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
index 3bc61c5e0c..0168c36abc 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
@@ -1,6 +1,42 @@
 module ActiveRecord
   module ConnectionAdapters
     class PostgreSQLAdapter < AbstractAdapter
+      class SchemaCreation < AbstractAdapter::SchemaCreation
+        private
+
+        def visit_AddColumn(o)
+          sql_type = type_to_sql(o.type.to_sym, o.limit, o.precision, o.scale)
+          sql = "ADD COLUMN #{quote_column_name(o.name)} #{sql_type}"
+          add_column_options!(sql, column_options(o))
+        end
+
+        def visit_ColumnDefinition(o)
+          sql = super
+          if o.primary_key? && o.type == :uuid
+            sql << " PRIMARY KEY "
+            add_column_options!(sql, column_options(o))
+          end
+          sql
+        end
+
+        def add_column_options!(sql, options)
+          if options[:array] || options[:column].try(:array)
+            sql << '[]'
+          end
+
+          column = options.fetch(:column) { return super }
+          if column.type == :uuid && options[:default] =~ /\(\)/
+            sql << " DEFAULT #{options[:default]}"
+          else
+            super
+          end
+        end
+      end
+
+      def schema_creation
+        SchemaCreation.new self
+      end
+
       module SchemaStatements
         # Drops the database specified on the +name+ attribute
         # and creates it again using the provided +options+.
@@ -124,8 +160,9 @@ module ActiveRecord
             desc_order_columns = inddef.scan(/(\w+) DESC/).flatten
             orders = desc_order_columns.any? ? Hash[desc_order_columns.map {|order_column| [order_column, :desc]}] : {}
             where = inddef.scan(/WHERE (.+)$/).flatten[0]
+            using = inddef.scan(/USING (.+?) /).flatten[0].to_sym
 
-            column_names.empty? ? nil : IndexDefinition.new(table_name, index_name, unique, column_names, [], orders, where)
+            column_names.empty? ? nil : IndexDefinition.new(table_name, index_name, unique, column_names, [], orders, where, nil, using)
           end.compact
         end
 
@@ -337,10 +374,7 @@ module ActiveRecord
         # See TableDefinition#column for details of the options you can use.
         def add_column(table_name, column_name, type, options = {})
           clear_cache!
-          add_column_sql = "ALTER TABLE #{quote_table_name(table_name)} ADD COLUMN #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"
-          add_column_options!(add_column_sql, options)
-
-          execute add_column_sql
+          super
         end
 
         # Changes the column of a table.
@@ -375,6 +409,11 @@ module ActiveRecord
           rename_column_indexes(table_name, column_name, new_column_name)
         end
 
+        def add_index(table_name, column_name, options = {}) #:nodoc:
+          index_name, index_type, index_columns, index_options, index_algorithm, index_using = add_index_options(table_name, column_name, options)
+          execute "CREATE #{index_type} INDEX #{index_algorithm} #{quote_column_name(index_name)} ON #{quote_table_name(table_name)} #{index_using} (#{index_columns})#{index_options}"
+        end
+
         def remove_index!(table_name, index_name) #:nodoc:
           execute "DROP INDEX #{quote_table_name(index_name)}"
         end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index 2115d960fa..e34e1fc10c 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -330,6 +330,13 @@ module ActiveRecord
       class TableDefinition < ActiveRecord::ConnectionAdapters::TableDefinition
         include ColumnMethods
 
+        def primary_key(name, type = :primary_key, options = {})
+          return super unless type == :uuid
+          options[:default] ||= 'uuid_generate_v4()'
+          options[:primary_key] = true
+          column name, type, options
+        end
+
         def column(name, type = nil, options = {})
           super
           column = self[name]
@@ -338,13 +345,14 @@ module ActiveRecord
           self
         end
 
+        def xml(options = {})
+          column(args[0], :text, options)
+        end
+
         private
 
-        def new_column_definition(base, name, type)
-          definition = ColumnDefinition.new base, name, type
-          @columns << definition
-          @columns_hash[name] = definition
-          definition
+        def create_column_definition(name, type)
+          ColumnDefinition.new name, type
         end
       end
 
@@ -425,6 +433,10 @@ module ActiveRecord
         true
       end
 
+      def index_algorithms
+        { concurrently: 'CONCURRENTLY' }
+      end
+
       class StatementPool < ConnectionAdapters::StatementPool
         def initialize(connection, max)
           super
@@ -518,8 +530,7 @@ module ActiveRecord
 
       # Is this connection alive and ready for queries?
       def active?
-        @connection.query 'SELECT 1'
-        true
+        @connection.connect_poll != PG::PGRES_POLLING_FAILED
       rescue PGError
         false
       end
@@ -594,13 +605,13 @@ module ActiveRecord
       end
 
       def enable_extension(name)
-        exec_query("CREATE EXTENSION IF NOT EXISTS #{name}").tap {
+        exec_query("CREATE EXTENSION IF NOT EXISTS \"#{name}\"").tap {
           reload_type_map
         }
       end
 
       def disable_extension(name)
-        exec_query("DROP EXTENSION IF EXISTS #{name} CASCADE").tap {
+        exec_query("DROP EXTENSION IF EXISTS \"#{name}\" CASCADE").tap {
           reload_type_map
         }
       end
@@ -627,13 +638,6 @@ module ActiveRecord
         @table_alias_length ||= query('SHOW max_identifier_length', 'SCHEMA')[0][0].to_i
       end
 
-      def add_column_options!(sql, options)
-        if options[:array] || options[:column].try(:array)
-          sql << '[]'
-        end
-        super
-      end
-
       # Set the authorized user for this session
       def session_auth=(user)
         clear_cache!
@@ -663,6 +667,10 @@ module ActiveRecord
         @use_insert_returning
       end
 
+      def valid_type?(type)
+        !native_database_types[type].nil?
+      end
+
       protected
 
         # Returns the version of the connected PostgreSQL server.
@@ -707,7 +715,14 @@ module ActiveRecord
 
           # populate composite types
           nodes.find_all { |row| OID::TYPE_MAP.key? row['typelem'].to_i }.each do |row|
-            vector = OID::Vector.new row['typdelim'], OID::TYPE_MAP[row['typelem'].to_i]
+            if OID.registered_type? row['typname']
+              # this composite type is explicitly registered
+              vector = OID::NAMES[row['typname']]
+            else
+              # use the default for composite types
+              vector = OID::Vector.new row['typdelim'], OID::TYPE_MAP[row['typelem'].to_i]
+            end
+
             OID::TYPE_MAP[row['oid'].to_i] = vector
           end
 
@@ -894,8 +909,8 @@ module ActiveRecord
           $1.strip if $1
         end
 
-        def create_table_definition
-          TableDefinition.new(self)
+        def create_table_definition(name, temporary, options)
+          TableDefinition.new native_database_types, name, temporary, options
         end
 
         def update_table_definition(table_name, base)
diff --git a/activerecord/lib/active_record/connection_adapters/schema_cache.rb b/activerecord/lib/active_record/connection_adapters/schema_cache.rb
index 5839d1d3b4..1d7a22e831 100644
--- a/activerecord/lib/active_record/connection_adapters/schema_cache.rb
+++ b/activerecord/lib/active_record/connection_adapters/schema_cache.rb
@@ -1,7 +1,9 @@
+require 'active_support/deprecation/reporting'
+
 module ActiveRecord
   module ConnectionAdapters
     class SchemaCache
-      attr_reader :primary_keys, :tables, :version
+      attr_reader :version
       attr_accessor :connection
 
       def initialize(conn)
@@ -14,6 +16,15 @@ module ActiveRecord
         prepare_default_proc
       end
 
+      def primary_keys(table_name = nil)
+        if table_name
+          @primary_keys[table_name]
+        else
+          ActiveSupport::Deprecation.warn('call primary_keys with a table name!')
+          @primary_keys.dup
+        end
+      end
+
       # A cached lookup for table existence.
       def table_exists?(name)
         return @tables[name] if @tables.key? name
@@ -30,12 +41,22 @@ module ActiveRecord
         end
       end
 
+      def tables(name = nil)
+        if name
+          @tables[name]
+        else
+          ActiveSupport::Deprecation.warn('call tables with a name!')
+          @tables.dup
+        end
+      end
+
       # Get the columns for a table
       def columns(table = nil)
         if table
           @columns[table]
         else
-          @columns
+          ActiveSupport::Deprecation.warn('call columns with a table name!')
+          @columns.dup
         end
       end
 
@@ -45,7 +66,8 @@ module ActiveRecord
         if table
           @columns_hash[table]
         else
-          @columns_hash
+          ActiveSupport::Deprecation.warn('call columns_hash with a table name!')
+          @columns_hash.dup
         end
       end
 
@@ -58,6 +80,12 @@ module ActiveRecord
         @version = nil
       end
 
+      def size
+        [@columns, @columns_hash, @primary_keys, @tables].map { |x|
+          x.size
+        }.inject :+
+      end
+
       # Clear out internal caches for table with +table_name+.
       def clear_table_cache!(table_name)
         @columns.delete table_name
@@ -69,9 +97,9 @@ module ActiveRecord
       def marshal_dump
         # if we get current version during initialization, it happens stack over flow.
         @version = ActiveRecord::Migrator.current_version
-        [@version] + [:@columns, :@columns_hash, :@primary_keys, :@tables].map do |val|
-          self.instance_variable_get(val).inject({}) { |h, v| h[v[0]] = v[1]; h }
-        end
+        [@version] + [@columns, @columns_hash, @primary_keys, @tables].map { |val|
+          Hash[val]
+        }
       end
 
       def marshal_load(array)
@@ -87,7 +115,7 @@ module ActiveRecord
         end
 
         @columns_hash.default_proc = Proc.new do |h, table_name|
-          h[table_name] = Hash[columns[table_name].map { |col|
+          h[table_name] = Hash[columns(table_name).map { |col|
             [col.name, col]
           }]
         end
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
index 49966678d6..7d940fe1c9 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
@@ -458,7 +458,7 @@ module ActiveRecord
 
       def remove_column(table_name, column_name, type = nil, options = {}) #:nodoc:
         alter_table(table_name) do |definition|
-          definition.columns.delete(definition[column_name])
+          definition.remove_column column_name
         end
       end
 
@@ -583,9 +583,17 @@ module ActiveRecord
           quoted_columns = columns.map { |col| quote_column_name(col) } * ','
 
           quoted_to = quote_table_name(to)
+
+          raw_column_mappings = Hash[columns(from).map { |c| [c.name, c] }]
+
           exec_query("SELECT * FROM #{quote_table_name(from)}").each do |row|
             sql = "INSERT INTO #{quoted_to} (#{quoted_columns}) VALUES ("
-            sql << columns.map {|col| quote row[column_mappings[col]]} * ', '
+
+            column_values = columns.map do |col|
+              quote(row[column_mappings[col]], raw_column_mappings[col])
+            end
+
+            sql << column_values * ', '
             sql << ')'
             exec_query sql
           end