* prepare_sort_from_pathkeys
* Prepare to sort according to given pathkeys
*
- * This is used to set up for both Sort and MergeAppend nodes. It calculates
- * the executor's representation of the sort key information, and adjusts the
- * plan targetlist if needed to add resjunk sort columns.
+ * This is used to set up for Sort, MergeAppend, and Gather Merge nodes. It
+ * calculates the executor's representation of the sort key information, and
+ * adjusts the plan targetlist if needed to add resjunk sort columns.
*
* Input parameters:
* 'lefttree' is the plan node which yields input tuples
*
* If the pathkeys include expressions that aren't simple Vars, we will
* usually need to add resjunk items to the input plan's targetlist to
- * compute these expressions, since the Sort/MergeAppend node itself won't
+ * compute these expressions, since a Sort or MergeAppend node itself won't
* do any such calculations. If the input plan type isn't one that can do
* projections, this means adding a Result node just to do the projection.
* However, the caller can pass adjust_tlist_in_place = TRUE to force the