Fixed #26608 -- Added support for window expressions (OVER clause).

Thanks Josh Smeaton, Mariusz Felisiak, Sergey Fedoseev, Simon Charettes,
Adam Chainz/Johnson and Tim Graham for comments and reviews and Jamie
Cockburn for initial patch.

1 files changed, 13 insertions, 0 deletions

diff --git a/docs/releases/2.0.txt b/docs/releases/2.0.txt
index da898db67d..fd9cf8dfd3 100644
--- a/docs/releases/2.0.txt
+++ b/docs/releases/2.0.txt
@@ -52,6 +52,14 @@ Mobile-friendly ``contrib.admin``
 The admin is now responsive and supports all major mobile devices.
 Older browser may experience varying levels of graceful degradation.
 
+Window expressions
+------------------
+
+The new :class:`~django.db.models.expressions.Window` expression allows
+adding an ``OVER`` clause to querysets. You can use :ref:`window functions
+<window-functions>` and :ref:`aggregate functions <aggregation-functions>` in
+the expression.
+
 Minor features
 --------------
 
@@ -404,6 +412,11 @@ backends.
   requires that the arguments to ``OF`` be columns rather than tables, set
   ``DatabaseFeatures.select_for_update_of_column = True``.
 
+* To enable support for :class:`~django.db.models.expressions.Window`
+  expressions, set ``DatabaseFeatures.supports_over_clause`` to ``True``. You
+  may need to customize the ``DatabaseOperations.window_start_rows_start_end()``
+  and/or ``window_start_range_start_end()`` methods.
+
 * Third-party database backends should add a
   ``DatabaseOperations.cast_char_field_without_max_length`` attribute with the
   database data type that will be used in the