diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
new file mode 100644
index e1d805d..06f9742
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -724,11 +724,15 @@ adjustJoinTreeList(Query *parsetree, boo
  * attributes that have defaults and are not assigned to in the given tlist.
  * (We do not insert anything for default-less attributes, however.  The
  * planner will later insert NULLs for them, but there's no reason to slow
- * down rewriter processing with extra tlist nodes.)  Also, for both INSERT
- * and UPDATE, replace explicit DEFAULT specifications with column default
- * expressions.
+ * down rewriter processing with extra tlist nodes.  We also do not insert
+ * anything for stored generated columns; those are fixed up in the executor.)
  *
- * 2. Merge multiple entries for the same target attribute, or declare error
+ * 2. For INSERT and UPDATE, process any set-to-DEFAULT tlist entries.  Any
+ * entries for columns that have defaults are replaced with the column default
+ * expressions, and any entries for default-less or stored generated columns
+ * are removed (for the same reasons as above).
+ *
+ * 3. Merge multiple entries for the same target attribute, or declare error
  * if we can't.  Multiple entries are only allowed for INSERT/UPDATE of
  * portions of an array or record field, for example
  *			UPDATE table SET foo[2] = 42, foo[4] = 43;
@@ -736,11 +740,11 @@ adjustJoinTreeList(Query *parsetree, boo
  * the expression we want to produce in this case is like
  *		foo = array_set_element(array_set_element(foo, 2, 42), 4, 43)
  *
- * 3. Sort the tlist into standard order: non-junk fields in order by resno,
+ * 4. Sort the tlist into standard order: non-junk fields in order by resno,
  * then junk fields (these in no particular order).
  *
- * We must do items 1 and 2 before firing rewrite rules, else rewritten
- * references to NEW.foo will produce wrong or incomplete results.  Item 3
+ * We must do items 1, 2, and 3 before firing rewrite rules, else rewritten
+ * references to NEW.foo will produce wrong or incomplete results.  Item 4
  * is not needed for rewriting, but it is helpful for the planner, and we
  * can do it essentially for free while handling the other items.
  *