Support for partial inserts.

When inserting new records, only the fields which have been changed
from the defaults will actually be included in the INSERT statement.
The other fields will be populated by the database.

This is more efficient, and also means that it will be safe to
remove database columns without getting subsequent errors in running
app processes (so long as the code in those processes doesn't
contain any references to the removed column).

1 files changed, 13 insertions, 0 deletions

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index d52d6a7fde..b6ad6f82d8 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,5 +1,18 @@
 ## Rails 4.0.0 (unreleased) ##
 
+*   Support for partial inserts.
+
+    When inserting new records, only the fields which have been changed
+    from the defaults will actually be included in the INSERT statement.
+    The other fields will be populated by the database.
+
+    This is more efficient, and also means that it will be safe to
+    remove database columns without getting subsequent errors in running
+    app processes (so long as the code in those processes doesn't
+    contain any references to the removed column).
+
+    *Jon Leighton*
+
 *   Added `#update_columns` method which updates the attributes from
     the passed-in hash without calling save, hence skipping validations and
     callbacks. `ActiveRecordError` will be raised when called on new objects