Adjust tuplesort API to have bitwise option flags

This replaces the bool flag for randomAccess.  An upcoming patch requires
adding another option, so instead of breaking the API for that, then
breaking it again one day if we add more options, let's just break it
once.  Any boolean options we add in the future will just make use of an
unused bit in the flags.

Any extensions making use of tuplesorts will need to update their code
to pass TUPLESORT_RANDOMACCESS instead of true for randomAccess.
TUPLESORT_NONE can be used for a set of empty options.

Author: David Rowley
Reviewed-by: Justin Pryzby
Discussion: https://postgr.es/m/CAApHDvoH4ASzsAOyHcxkuY01Qf%2B%2B8JJ0paw%2B03dk%2BW25tQEcNQ%40mail.gmail.com

src/backend/access/gist/gistbuild.c

@@ -271,7 +271,7 @@ gistbuild(Relation heap, Relation index, IndexInfo *indexInfo)
 														  index,
 														  maintenance_work_mem,
 														  NULL,
-														  false);
+														  TUPLESORT_NONE);
 
 		/* Scan the table, adding all tuples to the tuplesort */
 		reltuples = table_index_build_scan(heap, index, indexInfo, true, true,

src/backend/access/hash/hashsort.c

@@ -86,7 +86,7 @@ _h_spoolinit(Relation heap, Relation index, uint32 num_buckets)
 												   hspool->max_buckets,
 												   maintenance_work_mem,
 												   NULL,
-												   false);
+												   TUPLESORT_NONE);
 
 	return hspool;
 }

src/backend/access/heap/heapam_handler.c

@@ -726,7 +726,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	if (use_sort)
 		tuplesort = tuplesort_begin_cluster(oldTupDesc, OldIndex,
 											maintenance_work_mem,
-											NULL, false);
+											NULL, TUPLESORT_NONE);
 	else
 		tuplesort = NULL;
 

src/backend/access/nbtree/nbtsort.c

@@ -436,7 +436,7 @@ _bt_spools_heapscan(Relation heap, Relation index, BTBuildState *buildstate,
 		tuplesort_begin_index_btree(heap, index, buildstate->isunique,
 									buildstate->nulls_not_distinct,
 									maintenance_work_mem, coordinate,
-									false);
+									TUPLESORT_NONE);
 
 	/*
 	 * If building a unique index, put dead tuples in a second spool to keep
@@ -475,7 +475,7 @@ _bt_spools_heapscan(Relation heap, Relation index, BTBuildState *buildstate,
 		 */
 		buildstate->spool2->sortstate =
 			tuplesort_begin_index_btree(heap, index, false, false, work_mem,
-										coordinate2, false);
+										coordinate2, TUPLESORT_NONE);
 	}
 
 	/* Fill spool using either serial or parallel heap scan */
@@ -1939,7 +1939,7 @@ _bt_parallel_scan_and_sort(BTSpool *btspool, BTSpool *btspool2,
 													 btspool->isunique,
 													 btspool->nulls_not_distinct,
 													 sortmem, coordinate,
-													 false);
+													 TUPLESORT_NONE);
 
 	/*
 	 * Just as with serial case, there may be a second spool.  If so, a

src/backend/catalog/index.c

@@ -3364,7 +3364,7 @@ validate_index(Oid heapId, Oid indexId, Snapshot snapshot)
 	state.tuplesort = tuplesort_begin_datum(INT8OID, Int8LessOperator,
 											InvalidOid, false,
 											maintenance_work_mem,
-											NULL, false);
+											NULL, TUPLESORT_NONE);
 	state.htups = state.itups = state.tups_inserted = 0;
 
 	/* ambulkdelete updates progress metrics */

src/backend/executor/nodeAgg.c

@@ -530,7 +530,7 @@ initialize_phase(AggState *aggstate, int newphase)
 												  sortnode->collations,
 												  sortnode->nullsFirst,
 												  work_mem,
-												  NULL, false);
+												  NULL, TUPLESORT_NONE);
 	}
 
 	aggstate->current_phase = newphase;
@@ -607,7 +607,7 @@ initialize_aggregate(AggState *aggstate, AggStatePerTrans pertrans,
 									  pertrans->sortOperators[0],
 									  pertrans->sortCollations[0],
 									  pertrans->sortNullsFirst[0],
-									  work_mem, NULL, false);
+									  work_mem, NULL, TUPLESORT_NONE);
 		}
 		else
 			pertrans->sortstates[aggstate->current_set] =
@@ -617,7 +617,7 @@ initialize_aggregate(AggState *aggstate, AggStatePerTrans pertrans,
 									 pertrans->sortOperators,
 									 pertrans->sortCollations,
 									 pertrans->sortNullsFirst,
-									 work_mem, NULL, false);
+									 work_mem, NULL, TUPLESORT_NONE);
 	}
 
 	/*

src/backend/executor/nodeIncrementalSort.c

@@ -315,7 +315,7 @@ switchToPresortedPrefixMode(PlanState *pstate)
 												&(plannode->sort.nullsFirst[nPresortedCols]),
 												work_mem,
 												NULL,
-												false);
+												TUPLESORT_NONE);
 		node->prefixsort_state = prefixsort_state;
 	}
 	else
@@ -616,7 +616,7 @@ ExecIncrementalSort(PlanState *pstate)
 												  plannode->sort.nullsFirst,
 												  work_mem,
 												  NULL,
-												  false);
+												  TUPLESORT_NONE);
 			node->fullsort_state = fullsort_state;
 		}
 		else

src/backend/executor/nodeSort.c

@@ -77,6 +77,7 @@ ExecSort(PlanState *pstate)
 		Sort	   *plannode = (Sort *) node->ss.ps.plan;
 		PlanState  *outerNode;
 		TupleDesc	tupDesc;
+		int			tuplesortopts = TUPLESORT_NONE;
 
 		SO1_printf("ExecSort: %s\n",
 				   "sorting subplan");
@@ -96,6 +97,9 @@ ExecSort(PlanState *pstate)
 		outerNode = outerPlanState(node);
 		tupDesc = ExecGetResultType(outerNode);
 
+		if (node->randomAccess)
+			tuplesortopts |= TUPLESORT_RANDOMACCESS;
+
 		if (node->datumSort)
 			tuplesortstate = tuplesort_begin_datum(TupleDescAttr(tupDesc, 0)->atttypid,
 												   plannode->sortOperators[0],
@@ -103,7 +107,7 @@ ExecSort(PlanState *pstate)
 												   plannode->nullsFirst[0],
 												   work_mem,
 												   NULL,
-												   node->randomAccess);
+												   tuplesortopts);
 		else
 			tuplesortstate = tuplesort_begin_heap(tupDesc,
 												  plannode->numCols,
@@ -113,7 +117,7 @@ ExecSort(PlanState *pstate)
 												  plannode->nullsFirst,
 												  work_mem,
 												  NULL,
-												  node->randomAccess);
+												  tuplesortopts);
 		if (node->bounded)
 			tuplesort_set_bound(tuplesortstate, node->bound);
 		node->tuplesortstate = (void *) tuplesortstate;

src/backend/utils/adt/orderedsetaggs.c

@@ -118,6 +118,7 @@ ordered_set_startup(FunctionCallInfo fcinfo, bool use_tuples)
 	OSAPerQueryState *qstate;
 	MemoryContext gcontext;
 	MemoryContext oldcontext;
+	int			tuplesortopt;
 
 	/*
 	 * Check we're called as aggregate (and not a window function), and get
@@ -283,6 +284,11 @@ ordered_set_startup(FunctionCallInfo fcinfo, bool use_tuples)
 	osastate->qstate = qstate;
 	osastate->gcontext = gcontext;
 
+	tuplesortopt = TUPLESORT_NONE;
+
+	if (qstate->rescan_needed)
+		tuplesortopt |= TUPLESORT_RANDOMACCESS;
+
 	/*
 	 * Initialize tuplesort object.
 	 */
@@ -295,7 +301,7 @@ ordered_set_startup(FunctionCallInfo fcinfo, bool use_tuples)
 												   qstate->sortNullsFirsts,
 												   work_mem,
 												   NULL,
-												   qstate->rescan_needed);
+												   tuplesortopt);
 	else
 		osastate->sortstate = tuplesort_begin_datum(qstate->sortColType,
 													qstate->sortOperator,
@@ -303,7 +309,7 @@ ordered_set_startup(FunctionCallInfo fcinfo, bool use_tuples)
 													qstate->sortNullsFirst,
 													work_mem,
 													NULL,
-													qstate->rescan_needed);
+													tuplesortopt);
 
 	osastate->number_of_rows = 0;
 	osastate->sort_done = false;

src/backend/utils/sort/tuplesort.c

@@ -246,7 +246,7 @@ struct Tuplesortstate
 {
 	TupSortStatus status;		/* enumerated value as shown above */
 	int			nKeys;			/* number of columns in sort key */
-	bool		randomAccess;	/* did caller request random access? */
+	int			sortopt;		/* Bitmask of flags used to setup sort */
 	bool		bounded;		/* did caller specify a maximum number of
 								 * tuples to return? */
 	bool		boundUsed;		/* true if we made use of a bounded heap */
@@ -564,12 +564,12 @@ struct Sharedsort
  * may or may not match the in-memory representation of the tuple ---
  * any conversion needed is the job of the writetup and readtup routines.
  *
- * If state->randomAccess is true, then the stored representation of the
+ * If state->sortopt contains TUPLESORT_RANDOMACCESS, then the stored
- * tuple must be followed by another "unsigned int" that is a copy of the
+ * representation of the tuple must be followed by another "unsigned int" that
- * length --- so the total tape space used is actually sizeof(unsigned int)
+ * is a copy of the length --- so the total tape space used is actually
- * more than the stored length value.  This allows read-backwards.  When
+ * sizeof(unsigned int) more than the stored length value.  This allows
- * randomAccess is not true, the write/read routines may omit the extra
+ * read-backwards.  When the random access flag was not specified, the
- * length word.
+ * write/read routines may omit the extra length word.
  *
  * writetup is expected to write both length words as well as the tuple
  * data.  When readtup is called, the tape is positioned just after the
@@ -614,7 +614,7 @@ struct Sharedsort
 
 static Tuplesortstate *tuplesort_begin_common(int workMem,
 											  SortCoordinate coordinate,
-											  bool randomAccess);
+											  int sortopt);
 static void tuplesort_begin_batch(Tuplesortstate *state);
 static void puttuple_common(Tuplesortstate *state, SortTuple *tuple);
 static bool consider_abort_common(Tuplesortstate *state);
@@ -806,21 +806,20 @@ qsort_tuple_int32_compare(SortTuple *a, SortTuple *b, Tuplesortstate *state)
  * Each variant of tuplesort_begin has a workMem parameter specifying the
  * maximum number of kilobytes of RAM to use before spilling data to disk.
  * (The normal value of this parameter is work_mem, but some callers use
- * other values.)  Each variant also has a randomAccess parameter specifying
+ * other values.)  Each variant also has a sortopt which is a bitmask of
- * whether the caller needs non-sequential access to the sort result.
+ * sort options.  See TUPLESORT_* definitions in tuplesort.h
  */
 
 static Tuplesortstate *
-tuplesort_begin_common(int workMem, SortCoordinate coordinate,
+tuplesort_begin_common(int workMem, SortCoordinate coordinate, int sortopt)
-					   bool randomAccess)
 {
 	Tuplesortstate *state;
 	MemoryContext maincontext;
 	MemoryContext sortcontext;
 	MemoryContext oldcontext;
 
-	/* See leader_takeover_tapes() remarks on randomAccess support */
+	/* See leader_takeover_tapes() remarks on random access support */
-	if (coordinate && randomAccess)
+	if (coordinate && (sortopt & TUPLESORT_RANDOMACCESS))
 		elog(ERROR, "random access disallowed under parallel sort");
 
 	/*
@@ -857,7 +856,7 @@ tuplesort_begin_common(int workMem, SortCoordinate coordinate,
 		pg_rusage_init(&state->ru_start);
 #endif
 
-	state->randomAccess = randomAccess;
+	state->sortopt = sortopt;
 	state->tuples = true;
 
 	/*
@@ -991,10 +990,10 @@ tuplesort_begin_heap(TupleDesc tupDesc,
 					 int nkeys, AttrNumber *attNums,
 					 Oid *sortOperators, Oid *sortCollations,
 					 bool *nullsFirstFlags,
-					 int workMem, SortCoordinate coordinate, bool randomAccess)
+					 int workMem, SortCoordinate coordinate, int sortopt)
 {
 	Tuplesortstate *state = tuplesort_begin_common(workMem, coordinate,
-												   randomAccess);
+												   sortopt);
 	MemoryContext oldcontext;
 	int			i;
 
@@ -1006,7 +1005,7 @@ tuplesort_begin_heap(TupleDesc tupDesc,
 	if (trace_sort)
 		elog(LOG,
 			 "begin tuple sort: nkeys = %d, workMem = %d, randomAccess = %c",
-			 nkeys, workMem, randomAccess ? 't' : 'f');
+			 nkeys, workMem, sortopt & TUPLESORT_RANDOMACCESS ? 't' : 'f');
 #endif
 
 	state->nKeys = nkeys;
@@ -1015,7 +1014,7 @@ tuplesort_begin_heap(TupleDesc tupDesc,
 								false,	/* no unique check */
 								nkeys,
 								workMem,
-								randomAccess,
+								sortopt & TUPLESORT_RANDOMACCESS,
 								PARALLEL_SORT(state));
 
 	state->comparetup = comparetup_heap;
@@ -1065,10 +1064,10 @@ Tuplesortstate *
 tuplesort_begin_cluster(TupleDesc tupDesc,
 						Relation indexRel,
 						int workMem,
-						SortCoordinate coordinate, bool randomAccess)
+						SortCoordinate coordinate, int sortopt)
 {
 	Tuplesortstate *state = tuplesort_begin_common(workMem, coordinate,
-												   randomAccess);
+												   sortopt);
 	BTScanInsert indexScanKey;
 	MemoryContext oldcontext;
 	int			i;
@@ -1082,7 +1081,7 @@ tuplesort_begin_cluster(TupleDesc tupDesc,
 		elog(LOG,
 			 "begin tuple sort: nkeys = %d, workMem = %d, randomAccess = %c",
 			 RelationGetNumberOfAttributes(indexRel),
-			 workMem, randomAccess ? 't' : 'f');
+			 workMem, sortopt & TUPLESORT_RANDOMACCESS ? 't' : 'f');
 #endif
 
 	state->nKeys = IndexRelationGetNumberOfKeyAttributes(indexRel);
@@ -1091,7 +1090,7 @@ tuplesort_begin_cluster(TupleDesc tupDesc,
 								false,	/* no unique check */
 								state->nKeys,
 								workMem,
-								randomAccess,
+								sortopt & TUPLESORT_RANDOMACCESS,
 								PARALLEL_SORT(state));
 
 	state->comparetup = comparetup_cluster;
@@ -1172,10 +1171,10 @@ tuplesort_begin_index_btree(Relation heapRel,
 							bool uniqueNullsNotDistinct,
 							int workMem,
 							SortCoordinate coordinate,
-							bool randomAccess)
+							int sortopt)
 {
 	Tuplesortstate *state = tuplesort_begin_common(workMem, coordinate,
-												   randomAccess);
+												   sortopt);
 	BTScanInsert indexScanKey;
 	MemoryContext oldcontext;
 	int			i;
@@ -1187,7 +1186,7 @@ tuplesort_begin_index_btree(Relation heapRel,
 		elog(LOG,
 			 "begin index sort: unique = %c, workMem = %d, randomAccess = %c",
 			 enforceUnique ? 't' : 'f',
-			 workMem, randomAccess ? 't' : 'f');
+			 workMem, sortopt & TUPLESORT_RANDOMACCESS ? 't' : 'f');
 #endif
 
 	state->nKeys = IndexRelationGetNumberOfKeyAttributes(indexRel);
@@ -1196,7 +1195,7 @@ tuplesort_begin_index_btree(Relation heapRel,
 								enforceUnique,
 								state->nKeys,
 								workMem,
-								randomAccess,
+								sortopt & TUPLESORT_RANDOMACCESS,
 								PARALLEL_SORT(state));
 
 	state->comparetup = comparetup_index_btree;
@@ -1254,10 +1253,10 @@ tuplesort_begin_index_hash(Relation heapRel,
 						   uint32 max_buckets,
 						   int workMem,
 						   SortCoordinate coordinate,
-						   bool randomAccess)
+						   int sortopt)
 {
 	Tuplesortstate *state = tuplesort_begin_common(workMem, coordinate,
-												   randomAccess);
+												   sortopt);
 	MemoryContext oldcontext;
 
 	oldcontext = MemoryContextSwitchTo(state->maincontext);
@@ -1270,7 +1269,8 @@ tuplesort_begin_index_hash(Relation heapRel,
 			 high_mask,
 			 low_mask,
 			 max_buckets,
-			 workMem, randomAccess ? 't' : 'f');
+			 workMem,
+			 sortopt & TUPLESORT_RANDOMACCESS ? 't' : 'f');
 #endif
 
 	state->nKeys = 1;			/* Only one sort column, the hash code */
@@ -1298,10 +1298,10 @@ tuplesort_begin_index_gist(Relation heapRel,
 						   Relation indexRel,
 						   int workMem,
 						   SortCoordinate coordinate,
-						   bool randomAccess)
+						   int sortopt)
 {
 	Tuplesortstate *state = tuplesort_begin_common(workMem, coordinate,
-												   randomAccess);
+												   sortopt);
 	MemoryContext oldcontext;
 	int			i;
 
@@ -1311,7 +1311,7 @@ tuplesort_begin_index_gist(Relation heapRel,
 	if (trace_sort)
 		elog(LOG,
 			 "begin index sort: workMem = %d, randomAccess = %c",
-			 workMem, randomAccess ? 't' : 'f');
+			 workMem, sortopt & TUPLESORT_RANDOMACCESS ? 't' : 'f');
 #endif
 
 	state->nKeys = IndexRelationGetNumberOfKeyAttributes(indexRel);
@@ -1354,10 +1354,10 @@ tuplesort_begin_index_gist(Relation heapRel,
 Tuplesortstate *
 tuplesort_begin_datum(Oid datumType, Oid sortOperator, Oid sortCollation,
 					  bool nullsFirstFlag, int workMem,
-					  SortCoordinate coordinate, bool randomAccess)
+					  SortCoordinate coordinate, int sortopt)
 {
 	Tuplesortstate *state = tuplesort_begin_common(workMem, coordinate,
-												   randomAccess);
+												   sortopt);
 	MemoryContext oldcontext;
 	int16		typlen;
 	bool		typbyval;
@@ -1368,7 +1368,7 @@ tuplesort_begin_datum(Oid datumType, Oid sortOperator, Oid sortCollation,
 	if (trace_sort)
 		elog(LOG,
 			 "begin datum sort: workMem = %d, randomAccess = %c",
-			 workMem, randomAccess ? 't' : 'f');
+			 workMem, sortopt & TUPLESORT_RANDOMACCESS ? 't' : 'f');
 #endif
 
 	state->nKeys = 1;			/* always a one-column sort */
@@ -1377,7 +1377,7 @@ tuplesort_begin_datum(Oid datumType, Oid sortOperator, Oid sortCollation,
 								false,	/* no unique check */
 								1,
 								workMem,
-								randomAccess,
+								sortopt & TUPLESORT_RANDOMACCESS,
 								PARALLEL_SORT(state));
 
 	state->comparetup = comparetup_datum;
@@ -2272,7 +2272,7 @@ tuplesort_gettuple_common(Tuplesortstate *state, bool forward,
 	switch (state->status)
 	{
 		case TSS_SORTEDINMEM:
-			Assert(forward || state->randomAccess);
+			Assert(forward || state->sortopt & TUPLESORT_RANDOMACCESS);
 			Assert(!state->slabAllocatorUsed);
 			if (forward)
 			{
@@ -2316,7 +2316,7 @@ tuplesort_gettuple_common(Tuplesortstate *state, bool forward,
 			break;
 
 		case TSS_SORTEDONTAPE:
-			Assert(forward || state->randomAccess);
+			Assert(forward || state->sortopt & TUPLESORT_RANDOMACCESS);
 			Assert(state->slabAllocatorUsed);
 
 			/*
@@ -3091,7 +3091,8 @@ mergeruns(Tuplesortstate *state)
 			 * sorted tape, we can stop at this point and do the final merge
 			 * on-the-fly.
 			 */
-			if (!state->randomAccess && state->nInputRuns <= state->nInputTapes
+			if ((state->sortopt & TUPLESORT_RANDOMACCESS) == 0
+				&& state->nInputRuns <= state->nInputTapes
 				&& !WORKER(state))
 			{
 				/* Tell logtape.c we won't be writing anymore */
@@ -3337,7 +3338,7 @@ tuplesort_rescan(Tuplesortstate *state)
 {
 	MemoryContext oldcontext = MemoryContextSwitchTo(state->sortcontext);
 
-	Assert(state->randomAccess);
+	Assert(state->sortopt & TUPLESORT_RANDOMACCESS);
 
 	switch (state->status)
 	{
@@ -3370,7 +3371,7 @@ tuplesort_markpos(Tuplesortstate *state)
 {
 	MemoryContext oldcontext = MemoryContextSwitchTo(state->sortcontext);
 
-	Assert(state->randomAccess);
+	Assert(state->sortopt & TUPLESORT_RANDOMACCESS);
 
 	switch (state->status)
 	{
@@ -3401,7 +3402,7 @@ tuplesort_restorepos(Tuplesortstate *state)
 {
 	MemoryContext oldcontext = MemoryContextSwitchTo(state->sortcontext);
 
-	Assert(state->randomAccess);
+	Assert(state->sortopt & TUPLESORT_RANDOMACCESS);
 
 	switch (state->status)
 	{
@@ -3998,7 +3999,8 @@ writetup_heap(Tuplesortstate *state, LogicalTape *tape, SortTuple *stup)
 
 	LogicalTapeWrite(tape, (void *) &tuplen, sizeof(tuplen));
 	LogicalTapeWrite(tape, (void *) tupbody, tupbodylen);
-	if (state->randomAccess)	/* need trailing length word? */
+	if (state->sortopt & TUPLESORT_RANDOMACCESS)	/* need trailing length
+													 * word? */
 		LogicalTapeWrite(tape, (void *) &tuplen, sizeof(tuplen));
 
 	if (!state->slabAllocatorUsed)
@@ -4021,7 +4023,8 @@ readtup_heap(Tuplesortstate *state, SortTuple *stup,
 	/* read in the tuple proper */
 	tuple->t_len = tuplen;
 	LogicalTapeReadExact(tape, tupbody, tupbodylen);
-	if (state->randomAccess)	/* need trailing length word? */
+	if (state->sortopt & TUPLESORT_RANDOMACCESS)	/* need trailing length
+													 * word? */
 		LogicalTapeReadExact(tape, &tuplen, sizeof(tuplen));
 	stup->tuple = (void *) tuple;
 	/* set up first-column key value */
@@ -4233,7 +4236,8 @@ writetup_cluster(Tuplesortstate *state, LogicalTape *tape, SortTuple *stup)
 	LogicalTapeWrite(tape, &tuplen, sizeof(tuplen));
 	LogicalTapeWrite(tape, &tuple->t_self, sizeof(ItemPointerData));
 	LogicalTapeWrite(tape, tuple->t_data, tuple->t_len);
-	if (state->randomAccess)	/* need trailing length word? */
+	if (state->sortopt & TUPLESORT_RANDOMACCESS)	/* need trailing length
+													 * word? */
 		LogicalTapeWrite(tape, &tuplen, sizeof(tuplen));
 
 	if (!state->slabAllocatorUsed)
@@ -4259,7 +4263,8 @@ readtup_cluster(Tuplesortstate *state, SortTuple *stup,
 	tuple->t_tableOid = InvalidOid;
 	/* Read in the tuple body */
 	LogicalTapeReadExact(tape, tuple->t_data, tuple->t_len);
-	if (state->randomAccess)	/* need trailing length word? */
+	if (state->sortopt & TUPLESORT_RANDOMACCESS)	/* need trailing length
+													 * word? */
 		LogicalTapeReadExact(tape, &tuplen, sizeof(tuplen));
 	stup->tuple = (void *) tuple;
 	/* set up first-column key value, if it's a simple column */
@@ -4483,7 +4488,8 @@ writetup_index(Tuplesortstate *state, LogicalTape *tape, SortTuple *stup)
 	tuplen = IndexTupleSize(tuple) + sizeof(tuplen);
 	LogicalTapeWrite(tape, (void *) &tuplen, sizeof(tuplen));
 	LogicalTapeWrite(tape, (void *) tuple, IndexTupleSize(tuple));
-	if (state->randomAccess)	/* need trailing length word? */
+	if (state->sortopt & TUPLESORT_RANDOMACCESS)	/* need trailing length
+													 * word? */
 		LogicalTapeWrite(tape, (void *) &tuplen, sizeof(tuplen));
 
 	if (!state->slabAllocatorUsed)
@@ -4501,7 +4507,8 @@ readtup_index(Tuplesortstate *state, SortTuple *stup,
 	IndexTuple	tuple = (IndexTuple) readtup_alloc(state, tuplen);
 
 	LogicalTapeReadExact(tape, tuple, tuplen);
-	if (state->randomAccess)	/* need trailing length word? */
+	if (state->sortopt & TUPLESORT_RANDOMACCESS)	/* need trailing length
+													 * word? */
 		LogicalTapeReadExact(tape, &tuplen, sizeof(tuplen));
 	stup->tuple = (void *) tuple;
 	/* set up first-column key value */
@@ -4571,7 +4578,8 @@ writetup_datum(Tuplesortstate *state, LogicalTape *tape, SortTuple *stup)
 
 	LogicalTapeWrite(tape, (void *) &writtenlen, sizeof(writtenlen));
 	LogicalTapeWrite(tape, waddr, tuplen);
-	if (state->randomAccess)	/* need trailing length word? */
+	if (state->sortopt & TUPLESORT_RANDOMACCESS)	/* need trailing length
+													 * word? */
 		LogicalTapeWrite(tape, (void *) &writtenlen, sizeof(writtenlen));
 
 	if (!state->slabAllocatorUsed && stup->tuple)
@@ -4611,7 +4619,8 @@ readtup_datum(Tuplesortstate *state, SortTuple *stup,
 		stup->tuple = raddr;
 	}
 
-	if (state->randomAccess)	/* need trailing length word? */
+	if (state->sortopt & TUPLESORT_RANDOMACCESS)	/* need trailing length
+													 * word? */
 		LogicalTapeReadExact(tape, &tuplen, sizeof(tuplen));
 }
 

src/include/utils/tuplesort.h

@@ -86,6 +86,12 @@ typedef enum
 	SORT_SPACE_TYPE_MEMORY
 } TuplesortSpaceType;
 
+/* Bitwise option flags for tuple sorts */
+#define TUPLESORT_NONE					0
+
+/* specifies whether non-sequential access to the sort result is required */
+#define	TUPLESORT_RANDOMACCESS			(1 << 0)
+
 typedef struct TuplesortInstrumentation
 {
 	TuplesortMethod sortMethod; /* sort algorithm used */
@@ -201,32 +207,33 @@ extern Tuplesortstate *tuplesort_begin_heap(TupleDesc tupDesc,
 											Oid *sortOperators, Oid *sortCollations,
 											bool *nullsFirstFlags,
 											int workMem, SortCoordinate coordinate,
-											bool randomAccess);
+											int sortopt);
 extern Tuplesortstate *tuplesort_begin_cluster(TupleDesc tupDesc,
 											   Relation indexRel, int workMem,
-											   SortCoordinate coordinate, bool randomAccess);
+											   SortCoordinate coordinate,
+											   int sortopt);
 extern Tuplesortstate *tuplesort_begin_index_btree(Relation heapRel,
 												   Relation indexRel,
 												   bool enforceUnique,
 												   bool uniqueNullsNotDistinct,
 												   int workMem, SortCoordinate coordinate,
-												   bool randomAccess);
+												   int sortopt);
 extern Tuplesortstate *tuplesort_begin_index_hash(Relation heapRel,
 												  Relation indexRel,
 												  uint32 high_mask,
 												  uint32 low_mask,
 												  uint32 max_buckets,
 												  int workMem, SortCoordinate coordinate,
-												  bool randomAccess);
+												  int sortopt);
 extern Tuplesortstate *tuplesort_begin_index_gist(Relation heapRel,
 												  Relation indexRel,
 												  int workMem, SortCoordinate coordinate,
-												  bool randomAccess);
+												  int sortopt);
 extern Tuplesortstate *tuplesort_begin_datum(Oid datumType,
 											 Oid sortOperator, Oid sortCollation,
 											 bool nullsFirstFlag,
 											 int workMem, SortCoordinate coordinate,
-											 bool randomAccess);
+											 int sortopt);
 
 extern void tuplesort_set_bound(Tuplesortstate *state, int64 bound);
 extern bool tuplesort_used_bound(Tuplesortstate *state);