Add section in documentation describing optimizer.reorder-windows feature flag

Author: maciejgrzybek

presto-docs/src/main/sphinx/admin.rst

@@ -10,5 +10,6 @@ Administration
     admin/properties
     admin/queue
     admin/resource-groups
+    admin/feature-toggles
     aws/emr
 

presto-docs/src/main/sphinx/admin/feature-toggles.rst

@@ -0,0 +1,16 @@
+===============
+Feature Toggles
+===============
+
+The default Presto settings should work well for most workloads. The following
+information may help you if some of the features are not working correctly for you.
+Though, if you think the behavior of a feature is unexpected, don't hesitate to file a bug report regardless if it's enabled or disabled by default.
+
+Config Properties
+-----------------
+
++--------------------------+---------------+------------------------------------------------------------------------------------------------------------------------------------------------------------+
+|Name of property          | Default value | Description                                                                                                                                                |
++==========================+===============+=======================================================================================================+++==================================================+
+|optimizer.reorder-windows | true          |Allow reordering windows in order to put those with the same partitioning next to each other. This may sometimes allow minimizing number of repartitionings.|
++--------------------------+---------------+------------------------------------------------------------------------------------------------------------------------------------------------------------+