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diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 97616ffc58..49f7b03464 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,5 +1,124 @@
 ## Rails 4.0.0 (unreleased) ##
 
+*   When copying migrations, preserve their magic comments and content encoding.
+
+    *OZAWA Sakuro*
+
+*   Fix ActiveRecord `subclass_from_attrs` when `eager_load` is false.
+    It cannot find subclass because all classes are loaded automatically
+    when it needs.
+
+    *Dmitry Vorotilin*
+
+*   When `:name` option is provided to `remove_index`, use it if there is no
+    index by the conventional name.
+
+    For example, previously if an index was removed like so
+    `remove_index :values, column: :value, name: 'a_different_name'`
+    the generated SQL would not contain the specified index name,
+    and hence the migration would fail.
+    Fixes #8858.
+
+    *Ezekiel Smithburg*
+
+*   Created block to by-pass the prepared statement bindings.
+    This will allow to compose fragments of large SQL statements to
+    avoid multiple round-trips between Ruby and the DB.
+
+    Example:
+
+        sql = Post.connection.unprepared_statement do
+          Post.first.comments.to_sql
+        end
+
+    *Cédric Fabianski*
+
+*   Change the semantics of combining scopes to be the same as combining
+    class methods which return scopes. For example:
+
+        class User < ActiveRecord::Base
+          scope :active,   -> { where state: 'active' }
+          scope :inactive, -> { where state: 'inactive' }
+        end
+
+        class Post < ActiveRecord::Base
+          def self.active
+            where state: 'active'
+          end
+
+          def self.inactive
+            where state: 'inactive'
+          end
+        end
+
+        ### BEFORE ###
+
+        User.where(state: 'active').where(state: 'inactive')
+        # => SELECT * FROM users WHERE state = 'active' AND state = 'inactive'
+
+        User.active.inactive
+        # => SELECT * FROM users WHERE state = 'inactive'
+
+        Post.active.inactive
+        # => SELECT * FROM posts WHERE state = 'active' AND state = 'inactive'
+
+        ### AFTER ###
+
+        User.active.inactive
+        # => SELECT * FROM posts WHERE state = 'active' AND state = 'inactive'
+
+    Before this change, invoking a scope would merge it into the current
+    scope and return the result. `Relation#merge` applies "last where
+    wins" logic to de-duplicate the conditions, but this lead to
+    confusing and inconsistent behaviour. This fixes that.
+
+    If you really do want the "last where wins" logic, you can opt-in to
+    it like so:
+
+        User.active.merge(User.inactive)
+
+    Fixes #7365.
+
+    *Neeraj Singh* and *Jon Leighton*
+
+*   Expand `#cache_key` to consult all relevant updated timestamps.
+
+    Previously only `updated_at` column was checked, now it will
+    consult other columns that received updated timestamps on save,
+    such as `updated_on`.  When multiple columns are present it will
+    use the most recent timestamp.
+    Fixes #9033.
+
+    *Brendon Murphy*
+
+*   Throw `NotImplementedError` when trying to instantiate `ActiveRecord::Base` or an abstract class.
+
+    *Aaron Weiner*
+
+*   Warn when `rake db:structure:dump` with a mysl database and
+    `mysqldump` is not in the PATH or fails.
+    Fixes #9518.
+
+    *Yves Senn*
+
+*   Remove `connection#structure_dump`, which is no longer used. *Yves Senn*
+
+*   Make it possible to execute migrations without a transaction even
+    if the database adapter supports DDL transactions.
+    Fixes #9483.
+
+    Example:
+
+        class ChangeEnum < ActiveRecord::Migration
+          disable_ddl_transaction!
+
+          def up
+            execute "ALTER TYPE model_size ADD VALUE 'new_value'"
+          end
+        end
+
+    *Yves Senn*
+
 *   Assigning "0.0" to a nullable numeric column does not make it dirty.
     Fix #9034.