Add a note about how chunks produces builtins.tuple()'s.

James William Pye · James William Pye · commit f5f2a76a3323 · 2010-03-18T16:04:26.000-07:00
diff --git a/postgresql/documentation/driver.txt b/postgresql/documentation/driver.txt
@@ -1044,6 +1044,11 @@ are seen as indexes and other objects are seen as keys::
 	>>> row["col0"]
 	't'
 
+However, this extra functionality is not free. The cost of instantiating
+`postgresql.types.Row` objects is quite measurable, so the `chunks()` execution
+method will produce `builtins.tuple` objects for cases where performance is
+critical.
+
 .. note::
  Attributes aren't used to provide access to values due to potential conflicts
  with existing method and property names.
