@@ -344,6 +344,12 @@ struct Tuplesortstate
344344TupleDesc tupDesc ;
345345SortSupport sortKeys ;/* array of length nKeys */
346346
347+ /*
348+ * This variable is shared by the single-key MinimalTuple case and the
349+ * Datum case. Otherwise it's NULL.
350+ */
351+ SortSupport onlyKey ;
352+
347353/*
348354 * These variables are specific to the CLUSTER case; they are set by
349355 * tuplesort_begin_cluster. Note CLUSTER also uses tupDesc and
@@ -365,9 +371,6 @@ struct Tuplesortstate
365371/* These are specific to the index_hash subcase: */
366372uint32 hash_mask ;/* mask for sortable part of hash code */
367373
368- /* This is initialized when, and only when, there's just one key. */
369- SortSupport onlyKey ;
370-
371374/*
372375 * These variables are specific to the Datum case; they are set by
373376 * tuplesort_begin_datum and used only by the DatumTuple routines.
@@ -497,7 +500,8 @@ static void reversedirection_datum(Tuplesortstate *state);
497500static void free_sort_tuple (Tuplesortstate * state ,SortTuple * stup );
498501
499502/*
500- * Special version of qsort, just for SortTuple objects.
503+ * Special versions of qsort just for SortTuple objects. We have one for the
504+ * single-key case (qsort_ssup) and one for multi-key cases (qsort_tuple).
501505 */
502506#include "qsort_tuple.c"
503507
@@ -1236,6 +1240,7 @@ tuplesort_performsort(Tuplesortstate *state)
12361240 */
12371241if (state -> memtupcount > 1 )
12381242{
1243+ /* Can we use the single-key sort function? */
12391244if (state -> onlyKey != NULL )
12401245qsort_ssup (state -> memtuples ,state -> memtupcount ,
12411246state -> onlyKey );
@@ -3061,7 +3066,6 @@ comparetup_index_btree(const SortTuple *a, const SortTuple *b,
30613066 * they *must* get compared at some stage of the sort --- otherwise the
30623067 * sort algorithm wouldn't have checked whether one must appear before the
30633068 * other.
3064- *
30653069 */
30663070if (state -> enforceUnique && !equal_hasnull )
30673071{
@@ -3243,9 +3247,9 @@ reversedirection_index_hash(Tuplesortstate *state)
32433247static int
32443248comparetup_datum (const SortTuple * a ,const SortTuple * b ,Tuplesortstate * state )
32453249{
3246- /* Not currently needed */
3247- elog ( ERROR , "comparetup_datum() should not be called" );
3248- return 0 ;
3250+ return ApplySortComparator ( a -> datum1 , a -> isnull1 ,
3251+ b -> datum1 , b -> isnull1 ,
3252+ state -> onlyKey ) ;
32493253}
32503254
32513255static void