Further adjustment of comment about qsort_tuple.

diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 95489ac3f3085f67b04a0d6ee45d860e5d7c4fcc..89698181dbf514456234d059bd448ca4aed04d32 100644 (file)
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -346,7 +346,7 @@ struct Tuplesortstate
 
        /*
         * This variable is shared by the single-key MinimalTuple case and the
-        * Datum case.  Otherwise it's NULL.
+        * Datum case (which both use qsort_ssup()).  Otherwise it's NULL.
         */
        SortSupport     onlyKey;
 
@@ -500,8 +500,11 @@ static void reversedirection_datum(Tuplesortstate *state);
 static void free_sort_tuple(Tuplesortstate *state, SortTuple *stup);
 
 /*
- * Special versions of qsort just for SortTuple objects.  We have one for the
- * single-key case (qsort_ssup) and one for multi-key cases (qsort_tuple).
+ * Special versions of qsort just for SortTuple objects.  qsort_tuple() sorts
+ * any variant of SortTuples, using the appropriate comparetup function.
+ * qsort_ssup() is specialized for the case where the comparetup function
+ * reduces to ApplySortComparator(), that is single-key MinimalTuple sorts
+ * and Datum sorts.
  */
 #include "qsort_tuple.c"