From 29c94e03c7d05d2b29afa1de32795ce178531246 Mon Sep 17 00:00:00 2001
From: Andres Freund <andres@anarazel.de>
Date: Tue, 25 Sep 2018 16:27:48 -0700
Subject: [PATCH] Split ExecStoreTuple into ExecStoreHeapTuple and
 ExecStoreBufferHeapTuple.

Upcoming changes introduce further types of tuple table slots, in
preparation of making table storage pluggable. New storage methods
will have different representation of tuples, therefore the slot
accessor should refer explicitly to heap tuples.

Instead of just renaming the functions, split it into one function
that accepts heap tuples not residing in buffers, and one accepting
ones in buffers.  Previously one function was used for both, but that
was a bit awkward already, and splitting will allow us to represent
slot types for tuples in buffers and normal memory separately.

This is split out from the patch introducing abstract slots, as this
largely consists out of mechanical changes.

Author: Ashutosh Bapat
Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/20180220224318.gw4oe5jadhpmcdnm@alap3.anarazel.de
---
 contrib/postgres_fdw/postgres_fdw.c       |  11 +-
 src/backend/access/heap/heapam.c          |   4 +-
 src/backend/catalog/index.c               |   6 +-
 src/backend/catalog/indexing.c            |   2 +-
 src/backend/commands/analyze.c            |   2 +-
 src/backend/commands/constraint.c         |   2 +-
 src/backend/commands/copy.c               |   4 +-
 src/backend/commands/functioncmds.c       |   2 +-
 src/backend/commands/tablecmds.c          |   6 +-
 src/backend/commands/trigger.c            |  12 +--
 src/backend/executor/execIndexing.c       |   2 +-
 src/backend/executor/execMain.c           |   8 +-
 src/backend/executor/execPartition.c      |   4 +-
 src/backend/executor/execReplication.c    |   4 +-
 src/backend/executor/execScan.c           |   4 +-
 src/backend/executor/execTuples.c         | 124 ++++++++++++++--------
 src/backend/executor/nodeAgg.c            |   7 +-
 src/backend/executor/nodeBitmapHeapscan.c |   7 +-
 src/backend/executor/nodeGather.c         |   8 +-
 src/backend/executor/nodeGatherMerge.c    |   9 +-
 src/backend/executor/nodeIndexonlyscan.c  |   2 +-
 src/backend/executor/nodeIndexscan.c      |  20 ++--
 src/backend/executor/nodeModifyTable.c    |   4 +-
 src/backend/executor/nodeSamplescan.c     |   7 +-
 src/backend/executor/nodeSeqscan.c        |  11 +-
 src/backend/executor/nodeSetOp.c          |   7 +-
 src/backend/executor/nodeTidscan.c        |  16 ++-
 src/backend/partitioning/partbounds.c     |   2 +-
 src/backend/replication/logical/worker.c  |   2 +-
 src/backend/utils/adt/selfuncs.c          |   4 +-
 src/backend/utils/sort/tuplesort.c        |   4 +-
 src/include/executor/tuptable.h           |  10 +-
 32 files changed, 172 insertions(+), 145 deletions(-)

diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c
index e4e330397e..6cbba97c22 100644
--- a/contrib/postgres_fdw/postgres_fdw.c
+++ b/contrib/postgres_fdw/postgres_fdw.c
@@ -1443,10 +1443,9 @@ postgresIterateForeignScan(ForeignScanState *node)
 	/*
 	 * Return the next tuple.
 	 */
-	ExecStoreTuple(fsstate->tuples[fsstate->next_tuple++],
-				   slot,
-				   InvalidBuffer,
-				   false);
+	ExecStoreHeapTuple(fsstate->tuples[fsstate->next_tuple++],
+					   slot,
+					   false);
 
 	return slot;
 }
@@ -3517,7 +3516,7 @@ store_returning_result(PgFdwModifyState *fmstate,
 											NULL,
 											fmstate->temp_cxt);
 		/* tuple will be deleted when it is cleared from the slot */
-		ExecStoreTuple(newtup, slot, InvalidBuffer, true);
+		ExecStoreHeapTuple(newtup, slot, true);
 	}
 	PG_CATCH();
 	{
@@ -3790,7 +3789,7 @@ get_returning_data(ForeignScanState *node)
 												dmstate->retrieved_attrs,
 												node,
 												dmstate->temp_cxt);
-			ExecStoreTuple(newtup, slot, InvalidBuffer, false);
+			ExecStoreHeapTuple(newtup, slot, false);
 		}
 		PG_CATCH();
 		{
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index 56f1d82f96..3395445a9a 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -4502,14 +4502,14 @@ ProjIndexIsUnchanged(Relation relation, HeapTuple oldtup, HeapTuple newtup)
 			int			i;
 
 			ResetExprContext(econtext);
-			ExecStoreTuple(oldtup, slot, InvalidBuffer, false);
+			ExecStoreHeapTuple(oldtup, slot, false);
 			FormIndexDatum(indexInfo,
 						   slot,
 						   estate,
 						   old_values,
 						   old_isnull);
 
-			ExecStoreTuple(newtup, slot, InvalidBuffer, false);
+			ExecStoreHeapTuple(newtup, slot, false);
 			FormIndexDatum(indexInfo,
 						   slot,
 						   estate,
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 7eb3e35166..9229f619d2 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -2866,7 +2866,7 @@ IndexBuildHeapRangeScan(Relation heapRelation,
 		MemoryContextReset(econtext->ecxt_per_tuple_memory);
 
 		/* Set up for predicate or expression evaluation */
-		ExecStoreTuple(heapTuple, slot, InvalidBuffer, false);
+		ExecStoreHeapTuple(heapTuple, slot, false);
 
 		/*
 		 * In a partial index, discard tuples that don't satisfy the
@@ -3015,7 +3015,7 @@ IndexCheckExclusion(Relation heapRelation,
 		MemoryContextReset(econtext->ecxt_per_tuple_memory);
 
 		/* Set up for predicate or expression evaluation */
-		ExecStoreTuple(heapTuple, slot, InvalidBuffer, false);
+		ExecStoreHeapTuple(heapTuple, slot, false);
 
 		/*
 		 * In a partial index, ignore tuples that don't satisfy the predicate.
@@ -3436,7 +3436,7 @@ validate_index_heapscan(Relation heapRelation,
 			MemoryContextReset(econtext->ecxt_per_tuple_memory);
 
 			/* Set up for predicate or expression evaluation */
-			ExecStoreTuple(heapTuple, slot, InvalidBuffer, false);
+			ExecStoreHeapTuple(heapTuple, slot, false);
 
 			/*
 			 * In a partial index, discard tuples that don't satisfy the
diff --git a/src/backend/catalog/indexing.c b/src/backend/catalog/indexing.c
index 5a361683da..4674beaf3e 100644
--- a/src/backend/catalog/indexing.c
+++ b/src/backend/catalog/indexing.c
@@ -96,7 +96,7 @@ CatalogIndexInsert(CatalogIndexState indstate, HeapTuple heapTuple)
 
 	/* Need a slot to hold the tuple being examined */
 	slot = MakeSingleTupleTableSlot(RelationGetDescr(heapRelation));
-	ExecStoreTuple(heapTuple, slot, InvalidBuffer, false);
+	ExecStoreHeapTuple(heapTuple, slot, false);
 
 	/*
 	 * for each index, form and insert the index tuple
diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index 2503ac6510..d11b559b20 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -799,7 +799,7 @@ compute_index_stats(Relation onerel, double totalrows,
 			ResetExprContext(econtext);
 
 			/* Set up for predicate or expression evaluation */
-			ExecStoreTuple(heapTuple, slot, InvalidBuffer, false);
+			ExecStoreHeapTuple(heapTuple, slot, false);
 
 			/* If index is partial, check predicate */
 			if (predicate != NULL)
diff --git a/src/backend/commands/constraint.c b/src/backend/commands/constraint.c
index 90f19ad3dd..f472355b48 100644
--- a/src/backend/commands/constraint.c
+++ b/src/backend/commands/constraint.c
@@ -124,7 +124,7 @@ unique_key_recheck(PG_FUNCTION_ARGS)
 	 */
 	slot = MakeSingleTupleTableSlot(RelationGetDescr(trigdata->tg_relation));
 
-	ExecStoreTuple(new_row, slot, InvalidBuffer, false);
+	ExecStoreHeapTuple(new_row, slot, false);
 
 	/*
 	 * Typically the index won't have expressions, but if it does we need an
diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index 9bc67ce60f..d06662bd32 100644
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -2684,7 +2684,7 @@ CopyFrom(CopyState cstate)
 
 		/* Place tuple in tuple slot --- but slot shouldn't free it */
 		slot = myslot;
-		ExecStoreTuple(tuple, slot, InvalidBuffer, false);
+		ExecStoreHeapTuple(tuple, slot, false);
 
 		/* Determine the partition to heap_insert the tuple into */
 		if (proute)
@@ -3119,7 +3119,7 @@ CopyFromInsertBatch(CopyState cstate, EState *estate, CommandId mycid,
 			List	   *recheckIndexes;
 
 			cstate->cur_lineno = firstBufferedLineNo + i;
-			ExecStoreTuple(bufferedTuples[i], myslot, InvalidBuffer, false);
+			ExecStoreHeapTuple(bufferedTuples[i], myslot, false);
 			recheckIndexes =
 				ExecInsertIndexTuples(myslot, &(bufferedTuples[i]->t_self),
 									  estate, false, NULL, NIL);
diff --git a/src/backend/commands/functioncmds.c b/src/backend/commands/functioncmds.c
index 68109bfda0..6f629a00e8 100644
--- a/src/backend/commands/functioncmds.c
+++ b/src/backend/commands/functioncmds.c
@@ -2337,7 +2337,7 @@ ExecuteCallStmt(CallStmt *stmt, ParamListInfo params, bool atomic, DestReceiver
 		rettupdata.t_tableOid = InvalidOid;
 		rettupdata.t_data = td;
 
-		slot = ExecStoreTuple(&rettupdata, tstate->slot, InvalidBuffer, false);
+		slot = ExecStoreHeapTuple(&rettupdata, tstate->slot, false);
 		tstate->dest->receiveSlot(slot, tstate->dest);
 
 		end_tup_output(tstate);
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 03c0b739b3..1205dbc0b5 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -4776,7 +4776,7 @@ ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode)
 				 * Process supplied expressions to replace selected columns.
 				 * Expression inputs come from the old tuple.
 				 */
-				ExecStoreTuple(tuple, oldslot, InvalidBuffer, false);
+				ExecStoreHeapTuple(tuple, oldslot, false);
 				econtext->ecxt_scantuple = oldslot;
 
 				foreach(l, tab->newvals)
@@ -4806,7 +4806,7 @@ ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode)
 			}
 
 			/* Now check any constraints on the possibly-changed tuple */
-			ExecStoreTuple(tuple, newslot, InvalidBuffer, false);
+			ExecStoreHeapTuple(tuple, newslot, false);
 			econtext->ecxt_scantuple = newslot;
 
 			foreach(l, notnull_attrs)
@@ -8526,7 +8526,7 @@ validateCheckConstraint(Relation rel, HeapTuple constrtup)
 
 	while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 	{
-		ExecStoreTuple(tuple, slot, InvalidBuffer, false);
+		ExecStoreHeapTuple(tuple, slot, false);
 
 		if (!ExecCheck(exprstate, econtext))
 			ereport(ERROR,
diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c
index 0665f110ba..36778b6f4d 100644
--- a/src/backend/commands/trigger.c
+++ b/src/backend/commands/trigger.c
@@ -2571,7 +2571,7 @@ ExecBRInsertTriggers(EState *estate, ResultRelInfo *relinfo,
 
 		if (newslot->tts_tupleDescriptor != tupdesc)
 			ExecSetSlotDescriptor(newslot, tupdesc);
-		ExecStoreTuple(newtuple, newslot, InvalidBuffer, false);
+		ExecStoreHeapTuple(newtuple, newslot, false);
 		slot = newslot;
 	}
 	return slot;
@@ -2652,7 +2652,7 @@ ExecIRInsertTriggers(EState *estate, ResultRelInfo *relinfo,
 
 		if (newslot->tts_tupleDescriptor != tupdesc)
 			ExecSetSlotDescriptor(newslot, tupdesc);
-		ExecStoreTuple(newtuple, newslot, InvalidBuffer, false);
+		ExecStoreHeapTuple(newtuple, newslot, false);
 		slot = newslot;
 	}
 	return slot;
@@ -3078,7 +3078,7 @@ ExecBRUpdateTriggers(EState *estate, EPQState *epqstate,
 
 		if (newslot->tts_tupleDescriptor != tupdesc)
 			ExecSetSlotDescriptor(newslot, tupdesc);
-		ExecStoreTuple(newtuple, newslot, InvalidBuffer, false);
+		ExecStoreHeapTuple(newtuple, newslot, false);
 		slot = newslot;
 	}
 	return slot;
@@ -3186,7 +3186,7 @@ ExecIRUpdateTriggers(EState *estate, ResultRelInfo *relinfo,
 
 		if (newslot->tts_tupleDescriptor != tupdesc)
 			ExecSetSlotDescriptor(newslot, tupdesc);
-		ExecStoreTuple(newtuple, newslot, InvalidBuffer, false);
+		ExecStoreHeapTuple(newtuple, newslot, false);
 		slot = newslot;
 	}
 	return slot;
@@ -3514,7 +3514,7 @@ TriggerEnabled(EState *estate, ResultRelInfo *relinfo,
 			oldslot = estate->es_trig_oldtup_slot;
 			if (oldslot->tts_tupleDescriptor != tupdesc)
 				ExecSetSlotDescriptor(oldslot, tupdesc);
-			ExecStoreTuple(oldtup, oldslot, InvalidBuffer, false);
+			ExecStoreHeapTuple(oldtup, oldslot, false);
 		}
 		if (HeapTupleIsValid(newtup))
 		{
@@ -3528,7 +3528,7 @@ TriggerEnabled(EState *estate, ResultRelInfo *relinfo,
 			newslot = estate->es_trig_newtup_slot;
 			if (newslot->tts_tupleDescriptor != tupdesc)
 				ExecSetSlotDescriptor(newslot, tupdesc);
-			ExecStoreTuple(newtup, newslot, InvalidBuffer, false);
+			ExecStoreHeapTuple(newtup, newslot, false);
 		}
 
 		/*
diff --git a/src/backend/executor/execIndexing.c b/src/backend/executor/execIndexing.c
index 903076ee3c..9927ad70e6 100644
--- a/src/backend/executor/execIndexing.c
+++ b/src/backend/executor/execIndexing.c
@@ -750,7 +750,7 @@ retry:
 		 * Extract the index column values and isnull flags from the existing
 		 * tuple.
 		 */
-		ExecStoreTuple(tup, existing_slot, InvalidBuffer, false);
+		ExecStoreHeapTuple(tup, existing_slot, false);
 		FormIndexDatum(indexInfo, existing_slot, estate,
 					   existing_values, existing_isnull);
 
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 04f14c9178..5443cbf67d 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -1957,7 +1957,7 @@ ExecPartitionCheckEmitError(ResultRelInfo *resultRelInfo,
 		{
 			tuple = do_convert_tuple(tuple, map);
 			ExecSetSlotDescriptor(slot, tupdesc);
-			ExecStoreTuple(tuple, slot, InvalidBuffer, false);
+			ExecStoreHeapTuple(tuple, slot, false);
 		}
 	}
 
@@ -2036,7 +2036,7 @@ ExecConstraints(ResultRelInfo *resultRelInfo,
 					{
 						tuple = do_convert_tuple(tuple, map);
 						ExecSetSlotDescriptor(slot, tupdesc);
-						ExecStoreTuple(tuple, slot, InvalidBuffer, false);
+						ExecStoreHeapTuple(tuple, slot, false);
 					}
 				}
 
@@ -2084,7 +2084,7 @@ ExecConstraints(ResultRelInfo *resultRelInfo,
 				{
 					tuple = do_convert_tuple(tuple, map);
 					ExecSetSlotDescriptor(slot, tupdesc);
-					ExecStoreTuple(tuple, slot, InvalidBuffer, false);
+					ExecStoreHeapTuple(tuple, slot, false);
 				}
 			}
 
@@ -2190,7 +2190,7 @@ ExecWithCheckOptions(WCOKind kind, ResultRelInfo *resultRelInfo,
 						{
 							tuple = do_convert_tuple(tuple, map);
 							ExecSetSlotDescriptor(slot, tupdesc);
-							ExecStoreTuple(tuple, slot, InvalidBuffer, false);
+							ExecStoreHeapTuple(tuple, slot, false);
 						}
 					}
 
diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c
index 38ecc4192e..ec7a5267c3 100644
--- a/src/backend/executor/execPartition.c
+++ b/src/backend/executor/execPartition.c
@@ -258,7 +258,7 @@ ExecFindPartition(ResultRelInfo *resultRelInfo, PartitionDispatch *pd,
 		if (myslot != NULL && map != NULL)
 		{
 			tuple = do_convert_tuple(tuple, map);
-			ExecStoreTuple(tuple, myslot, InvalidBuffer, true);
+			ExecStoreHeapTuple(tuple, myslot, true);
 			slot = myslot;
 		}
 
@@ -842,7 +842,7 @@ ConvertPartitionTupleSlot(TupleConversionMap *map,
 	*p_my_slot = new_slot;
 	Assert(new_slot != NULL);
 	ExecSetSlotDescriptor(new_slot, map->outdesc);
-	ExecStoreTuple(tuple, new_slot, InvalidBuffer, shouldFree);
+	ExecStoreHeapTuple(tuple, new_slot, shouldFree);
 
 	return tuple;
 }
diff --git a/src/backend/executor/execReplication.c b/src/backend/executor/execReplication.c
index 9a7dedf5aa..25ba93e03c 100644
--- a/src/backend/executor/execReplication.c
+++ b/src/backend/executor/execReplication.c
@@ -146,7 +146,7 @@ retry:
 	if ((scantuple = index_getnext(scan, ForwardScanDirection)) != NULL)
 	{
 		found = true;
-		ExecStoreTuple(scantuple, outslot, InvalidBuffer, false);
+		ExecStoreHeapTuple(scantuple, outslot, false);
 		ExecMaterializeSlot(outslot);
 
 		xwait = TransactionIdIsValid(snap.xmin) ?
@@ -310,7 +310,7 @@ retry:
 			continue;
 
 		found = true;
-		ExecStoreTuple(scantuple, outslot, InvalidBuffer, false);
+		ExecStoreHeapTuple(scantuple, outslot, false);
 		ExecMaterializeSlot(outslot);
 
 		xwait = TransactionIdIsValid(snap.xmin) ?
diff --git a/src/backend/executor/execScan.c b/src/backend/executor/execScan.c
index f84a3fb0db..233cc28060 100644
--- a/src/backend/executor/execScan.c
+++ b/src/backend/executor/execScan.c
@@ -78,8 +78,8 @@ ExecScanFetch(ScanState *node,
 				return ExecClearTuple(slot);
 
 			/* Store test tuple in the plan node's scan slot */
-			ExecStoreTuple(estate->es_epqTuple[scanrelid - 1],
-						   slot, InvalidBuffer, false);
+			ExecStoreHeapTuple(estate->es_epqTuple[scanrelid - 1],
+							   slot, false);
 
 			/* Check if it meets the access-method conditions */
 			if (!(*recheckMtd) (node, slot))
diff --git a/src/backend/executor/execTuples.c b/src/backend/executor/execTuples.c
index c45dc246f6..573677af72 100644
--- a/src/backend/executor/execTuples.c
+++ b/src/backend/executor/execTuples.c
@@ -26,10 +26,10 @@
  *
  *		During ExecutorRun()
  *		----------------
- *		- SeqNext() calls ExecStoreTuple() to place the tuple returned
- *		  by the access methods into the scan tuple slot.
+ *		- SeqNext() calls ExecStoreBufferHeapTuple() to place the tuple
+ *		  returned by the access methods into the scan tuple slot.
  *
- *		- ExecSeqScan() calls ExecStoreTuple() to take the result
+ *		- ExecSeqScan() calls ExecStoreHeapTuple() to take the result
  *		  tuple from ExecProject() and place it into the result tuple slot.
  *
  *		- ExecutePlan() calls the output function.
@@ -287,48 +287,88 @@ ExecSetSlotDescriptor(TupleTableSlot *slot, /* slot to change */
 }
 
 /* --------------------------------
- *		ExecStoreTuple
+ *		ExecStoreHeapTuple
  *
- *		This function is used to store a physical tuple into a specified
+ *		This function is used to store an on-the-fly physical tuple into a specified
  *		slot in the tuple table.
  *
  *		tuple:	tuple to store
  *		slot:	slot to store it in
- *		buffer: disk buffer if tuple is in a disk page, else InvalidBuffer
  *		shouldFree: true if ExecClearTuple should pfree() the tuple
  *					when done with it
  *
- * If 'buffer' is not InvalidBuffer, the tuple table code acquires a pin
- * on the buffer which is held until the slot is cleared, so that the tuple
- * won't go away on us.
+ * shouldFree is normally set 'true' for tuples constructed on-the-fly.  But it
+ * can be 'false' when the referenced tuple is held in a tuple table slot
+ * belonging to a lower-level executor Proc node.  In this case the lower-level
+ * slot retains ownership and responsibility for eventually releasing the
+ * tuple.  When this method is used, we must be certain that the upper-level
+ * Proc node will lose interest in the tuple sooner than the lower-level one
+ * does!  If you're not certain, copy the lower-level tuple with heap_copytuple
+ * and let the upper-level table slot assume ownership of the copy!
  *
- * shouldFree is normally set 'true' for tuples constructed on-the-fly.
- * It must always be 'false' for tuples that are stored in disk pages,
- * since we don't want to try to pfree those.
+ * Return value is just the passed-in slot pointer.
+ * --------------------------------
+ */
+TupleTableSlot *
+ExecStoreHeapTuple(HeapTuple tuple,
+				   TupleTableSlot *slot,
+				   bool shouldFree)
+{
+	/*
+	 * sanity checks
+	 */
+	Assert(tuple != NULL);
+	Assert(slot != NULL);
+	Assert(slot->tts_tupleDescriptor != NULL);
+
+	/*
+	 * Free any old physical tuple belonging to the slot.
+	 */
+	if (slot->tts_shouldFree)
+		heap_freetuple(slot->tts_tuple);
+	if (slot->tts_shouldFreeMin)
+		heap_free_minimal_tuple(slot->tts_mintuple);
+
+	/*
+	 * Store the new tuple into the specified slot.
+	 */
+	slot->tts_isempty = false;
+	slot->tts_shouldFree = shouldFree;
+	slot->tts_shouldFreeMin = false;
+	slot->tts_tuple = tuple;
+	slot->tts_mintuple = NULL;
+
+	/* Mark extracted state invalid */
+	slot->tts_nvalid = 0;
+
+	/* Unpin any buffer pinned by the slot. */
+	if (BufferIsValid(slot->tts_buffer))
+		ReleaseBuffer(slot->tts_buffer);
+	slot->tts_buffer = InvalidBuffer;
+
+	return slot;
+}
+
+/* --------------------------------
+ *		ExecStoreBufferHeapTuple
  *
- * Another case where it is 'false' is when the referenced tuple is held
- * in a tuple table slot belonging to a lower-level executor Proc node.
- * In this case the lower-level slot retains ownership and responsibility
- * for eventually releasing the tuple.  When this method is used, we must
- * be certain that the upper-level Proc node will lose interest in the tuple
- * sooner than the lower-level one does!  If you're not certain, copy the
- * lower-level tuple with heap_copytuple and let the upper-level table
- * slot assume ownership of the copy!
+ *		This function is used to store an on-disk physical tuple from a buffer
+ *		into a specified slot in the tuple table.
  *
- * Return value is just the passed-in slot pointer.
+ *		tuple:	tuple to store
+ *		slot:	slot to store it in
+ *		buffer: disk buffer if tuple is in a disk page, else InvalidBuffer
+ *
+ * The tuple table code acquires a pin on the buffer which is held until the
+ * slot is cleared, so that the tuple won't go away on us.
  *
- * NOTE: before PostgreSQL 8.1, this function would accept a NULL tuple
- * pointer and effectively behave like ExecClearTuple (though you could
- * still specify a buffer to pin, which would be an odd combination).
- * This saved a couple lines of code in a few places, but seemed more likely
- * to mask logic errors than to be really useful, so it's now disallowed.
+ * Return value is just the passed-in slot pointer.
  * --------------------------------
  */
 TupleTableSlot *
-ExecStoreTuple(HeapTuple tuple,
-			   TupleTableSlot *slot,
-			   Buffer buffer,
-			   bool shouldFree)
+ExecStoreBufferHeapTuple(HeapTuple tuple,
+						 TupleTableSlot *slot,
+						 Buffer buffer)
 {
 	/*
 	 * sanity checks
@@ -336,8 +376,7 @@ ExecStoreTuple(HeapTuple tuple,
 	Assert(tuple != NULL);
 	Assert(slot != NULL);
 	Assert(slot->tts_tupleDescriptor != NULL);
-	/* passing shouldFree=true for a tuple on a disk page is not sane */
-	Assert(BufferIsValid(buffer) ? (!shouldFree) : true);
+	Assert(BufferIsValid(buffer));
 
 	/*
 	 * Free any old physical tuple belonging to the slot.
@@ -351,7 +390,7 @@ ExecStoreTuple(HeapTuple tuple,
 	 * Store the new tuple into the specified slot.
 	 */
 	slot->tts_isempty = false;
-	slot->tts_shouldFree = shouldFree;
+	slot->tts_shouldFree = false;
 	slot->tts_shouldFreeMin = false;
 	slot->tts_tuple = tuple;
 	slot->tts_mintuple = NULL;
@@ -360,21 +399,20 @@ ExecStoreTuple(HeapTuple tuple,
 	slot->tts_nvalid = 0;
 
 	/*
-	 * If tuple is on a disk page, keep the page pinned as long as we hold a
-	 * pointer into it.  We assume the caller already has such a pin.
+	 * Keep the disk page containing the given tuple pinned as long as we hold
+	 * a pointer into it.  We assume the caller already has such a pin.
 	 *
 	 * This is coded to optimize the case where the slot previously held a
-	 * tuple on the same disk page: in that case releasing and re-acquiring
-	 * the pin is a waste of cycles.  This is a common situation during
-	 * seqscans, so it's worth troubling over.
+	 * tuple on the same disk page: in that case releasing and re-acquiring the
+	 * pin is a waste of cycles.  This is a common situation during seqscans,
+	 * so it's worth troubling over.
 	 */
 	if (slot->tts_buffer != buffer)
 	{
 		if (BufferIsValid(slot->tts_buffer))
 			ReleaseBuffer(slot->tts_buffer);
 		slot->tts_buffer = buffer;
-		if (BufferIsValid(buffer))
-			IncrBufferRefCount(buffer);
+		IncrBufferRefCount(buffer);
 	}
 
 	return slot;
@@ -383,7 +421,7 @@ ExecStoreTuple(HeapTuple tuple,
 /* --------------------------------
  *		ExecStoreMinimalTuple
  *
- *		Like ExecStoreTuple, but insert a "minimal" tuple into the slot.
+ *		Like ExecStoreHeapTuple, but insert a "minimal" tuple into the slot.
  *
  * No 'buffer' parameter since minimal tuples are never stored in relations.
  * --------------------------------
@@ -652,7 +690,7 @@ ExecFetchSlotTuple(TupleTableSlot *slot)
 			tuple = heap_expand_tuple(slot->tts_tuple,
 									  slot->tts_tupleDescriptor);
 			MemoryContextSwitchTo(oldContext);
-			slot = ExecStoreTuple(tuple, slot, InvalidBuffer, true);
+			slot = ExecStoreHeapTuple(tuple, slot, true);
 		}
 		return slot->tts_tuple;
 	}
@@ -834,7 +872,7 @@ ExecCopySlot(TupleTableSlot *dstslot, TupleTableSlot *srcslot)
 	newTuple = ExecCopySlotTuple(srcslot);
 	MemoryContextSwitchTo(oldContext);
 
-	return ExecStoreTuple(newTuple, dstslot, InvalidBuffer, true);
+	return ExecStoreHeapTuple(newTuple, dstslot, true);
 }
 
 
diff --git a/src/backend/executor/nodeAgg.c b/src/backend/executor/nodeAgg.c
index 0fe0c22c1e..98d8483b72 100644
--- a/src/backend/executor/nodeAgg.c
+++ b/src/backend/executor/nodeAgg.c
@@ -1799,10 +1799,9 @@ agg_retrieve_direct(AggState *aggstate)
 				 * reserved for it.  The tuple will be deleted when it is
 				 * cleared from the slot.
 				 */
-				ExecStoreTuple(aggstate->grp_firstTuple,
-							   firstSlot,
-							   InvalidBuffer,
-							   true);
+				ExecStoreHeapTuple(aggstate->grp_firstTuple,
+								   firstSlot,
+								   true);
 				aggstate->grp_firstTuple = NULL;	/* don't keep two pointers */
 
 				/* set up for first advance_aggregates call */
diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c
index 3e1c9e0714..baffae27e3 100644
--- a/src/backend/executor/nodeBitmapHeapscan.c
+++ b/src/backend/executor/nodeBitmapHeapscan.c
@@ -340,10 +340,9 @@ BitmapHeapNext(BitmapHeapScanState *node)
 			 * Set up the result slot to point to this tuple.  Note that the
 			 * slot acquires a pin on the buffer.
 			 */
-			ExecStoreTuple(&scan->rs_ctup,
-						   slot,
-						   scan->rs_cbuf,
-						   false);
+			ExecStoreBufferHeapTuple(&scan->rs_ctup,
+									 slot,
+									 scan->rs_cbuf);
 
 			/*
 			 * If we are using lossy info, we have to recheck the qual
diff --git a/src/backend/executor/nodeGather.c b/src/backend/executor/nodeGather.c
index 4a700b7b30..ad16c783bd 100644
--- a/src/backend/executor/nodeGather.c
+++ b/src/backend/executor/nodeGather.c
@@ -257,11 +257,9 @@ gather_getnext(GatherState *gatherstate)
 
 			if (HeapTupleIsValid(tup))
 			{
-				ExecStoreTuple(tup, /* tuple to store */
-							   fslot,	/* slot in which to store the tuple */
-							   InvalidBuffer,	/* buffer associated with this
-												 * tuple */
-							   true);	/* pfree tuple when done with it */
+				ExecStoreHeapTuple(tup, /* tuple to store */
+								   fslot,	/* slot to store the tuple */
+								   true);	/* pfree tuple when done with it */
 				return fslot;
 			}
 		}
diff --git a/src/backend/executor/nodeGatherMerge.c b/src/backend/executor/nodeGatherMerge.c
index a0b3334bed..a1a11dfda1 100644
--- a/src/backend/executor/nodeGatherMerge.c
+++ b/src/backend/executor/nodeGatherMerge.c
@@ -679,11 +679,10 @@ gather_merge_readnext(GatherMergeState *gm_state, int reader, bool nowait)
 	Assert(HeapTupleIsValid(tup));
 
 	/* Build the TupleTableSlot for the given tuple */
-	ExecStoreTuple(tup,			/* tuple to store */
-				   gm_state->gm_slots[reader],	/* slot in which to store the
-												 * tuple */
-				   InvalidBuffer,	/* no buffer associated with tuple */
-				   true);		/* pfree tuple when done with it */
+	ExecStoreHeapTuple(tup,			/* tuple to store */
+					   gm_state->gm_slots[reader],	/* slot in which to store
+													 * the tuple */
+					   true);		/* pfree tuple when done with it */
 
 	return true;
 }
diff --git a/src/backend/executor/nodeIndexonlyscan.c b/src/backend/executor/nodeIndexonlyscan.c
index 8c32a74d39..4b6d531810 100644
--- a/src/backend/executor/nodeIndexonlyscan.c
+++ b/src/backend/executor/nodeIndexonlyscan.c
@@ -199,7 +199,7 @@ IndexOnlyNext(IndexOnlyScanState *node)
 			 */
 			Assert(slot->tts_tupleDescriptor->natts ==
 				   scandesc->xs_hitupdesc->natts);
-			ExecStoreTuple(scandesc->xs_hitup, slot, InvalidBuffer, false);
+			ExecStoreHeapTuple(scandesc->xs_hitup, slot, false);
 		}
 		else if (scandesc->xs_itup)
 			StoreIndexTuple(slot, scandesc->xs_itup, scandesc->xs_itupdesc);
diff --git a/src/backend/executor/nodeIndexscan.c b/src/backend/executor/nodeIndexscan.c
index 10891bc3f4..6285a2114e 100644
--- a/src/backend/executor/nodeIndexscan.c
+++ b/src/backend/executor/nodeIndexscan.c
@@ -140,10 +140,10 @@ IndexNext(IndexScanState *node)
 		 * Note: we pass 'false' because tuples returned by amgetnext are
 		 * pointers onto disk pages and must not be pfree()'d.
 		 */
-		ExecStoreTuple(tuple,	/* tuple to store */
-					   slot,	/* slot to store in */
-					   scandesc->xs_cbuf,	/* buffer containing tuple */
-					   false);	/* don't pfree */
+		ExecStoreBufferHeapTuple(tuple,	/* tuple to store */
+								 slot,	/* slot to store in */
+								 scandesc->xs_cbuf);	/* buffer containing
+														 * tuple */
 
 		/*
 		 * If the index was lossy, we have to recheck the index quals using
@@ -257,7 +257,7 @@ IndexNextWithReorder(IndexScanState *node)
 				tuple = reorderqueue_pop(node);
 
 				/* Pass 'true', as the tuple in the queue is a palloc'd copy */
-				ExecStoreTuple(tuple, slot, InvalidBuffer, true);
+				ExecStoreHeapTuple(tuple, slot, true);
 				return slot;
 			}
 		}
@@ -284,13 +284,11 @@ next_indextuple:
 
 		/*
 		 * Store the scanned tuple in the scan tuple slot of the scan state.
-		 * Note: we pass 'false' because tuples returned by amgetnext are
-		 * pointers onto disk pages and must not be pfree()'d.
 		 */
-		ExecStoreTuple(tuple,	/* tuple to store */
-					   slot,	/* slot to store in */
-					   scandesc->xs_cbuf,	/* buffer containing tuple */
-					   false);	/* don't pfree */
+		ExecStoreBufferHeapTuple(tuple,	/* tuple to store */
+								 slot,	/* slot to store in */
+								 scandesc->xs_cbuf);	/* buffer containing
+														 * tuple */
 
 		/*
 		 * If the index was lossy, we have to recheck the index quals and
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index d8d89c7983..bf0d5e8edb 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -888,7 +888,7 @@ ldelete:;
 
 			if (slot->tts_tupleDescriptor != RelationGetDescr(resultRelationDesc))
 				ExecSetSlotDescriptor(slot, RelationGetDescr(resultRelationDesc));
-			ExecStoreTuple(&deltuple, slot, InvalidBuffer, false);
+			ExecStoreHeapTuple(&deltuple, slot, false);
 		}
 
 		rslot = ExecProcessReturning(resultRelInfo, slot, planSlot);
@@ -1479,7 +1479,7 @@ ExecOnConflictUpdate(ModifyTableState *mtstate,
 	ExecCheckHeapTupleVisible(estate, &tuple, buffer);
 
 	/* Store target's existing tuple in the state's dedicated slot */
-	ExecStoreTuple(&tuple, mtstate->mt_existing, buffer, false);
+	ExecStoreBufferHeapTuple(&tuple, mtstate->mt_existing, buffer);
 
 	/*
 	 * Make tuple and any needed join variables available to ExecQual and
diff --git a/src/backend/executor/nodeSamplescan.c b/src/backend/executor/nodeSamplescan.c
index 15177dbed7..99528be84a 100644
--- a/src/backend/executor/nodeSamplescan.c
+++ b/src/backend/executor/nodeSamplescan.c
@@ -63,10 +63,9 @@ SampleNext(SampleScanState *node)
 	slot = node->ss.ss_ScanTupleSlot;
 
 	if (tuple)
-		ExecStoreTuple(tuple,	/* tuple to store */
-					   slot,	/* slot to store in */
-					   node->ss.ss_currentScanDesc->rs_cbuf,	/* tuple's buffer */
-					   false);	/* don't pfree this pointer */
+		ExecStoreBufferHeapTuple(tuple,	/* tuple to store */
+								 slot,	/* slot to store in */
+								 node->ss.ss_currentScanDesc->rs_cbuf);	/* tuple's buffer */
 	else
 		ExecClearTuple(slot);
 
diff --git a/src/backend/executor/nodeSeqscan.c b/src/backend/executor/nodeSeqscan.c
index c7849de6bc..cd53491be0 100644
--- a/src/backend/executor/nodeSeqscan.c
+++ b/src/backend/executor/nodeSeqscan.c
@@ -84,15 +84,14 @@ SeqNext(SeqScanState *node)
 	 * our scan tuple slot and return the slot.  Note: we pass 'false' because
 	 * tuples returned by heap_getnext() are pointers onto disk pages and were
 	 * not created with palloc() and so should not be pfree()'d.  Note also
-	 * that ExecStoreTuple will increment the refcount of the buffer; the
+	 * that ExecStoreHeapTuple will increment the refcount of the buffer; the
 	 * refcount will not be dropped until the tuple table slot is cleared.
 	 */
 	if (tuple)
-		ExecStoreTuple(tuple,	/* tuple to store */
-					   slot,	/* slot to store in */
-					   scandesc->rs_cbuf,	/* buffer associated with this
-											 * tuple */
-					   false);	/* don't pfree this pointer */
+		ExecStoreBufferHeapTuple(tuple,	/* tuple to store */
+								 slot,	/* slot to store in */
+								 scandesc->rs_cbuf);	/* buffer associated
+														 * with this tuple */
 	else
 		ExecClearTuple(slot);
 
diff --git a/src/backend/executor/nodeSetOp.c b/src/backend/executor/nodeSetOp.c
index 3fa4a5fcc6..3535b19c41 100644
--- a/src/backend/executor/nodeSetOp.c
+++ b/src/backend/executor/nodeSetOp.c
@@ -267,10 +267,9 @@ setop_retrieve_direct(SetOpState *setopstate)
 		 * for it.  The tuple will be deleted when it is cleared from the
 		 * slot.
 		 */
-		ExecStoreTuple(setopstate->grp_firstTuple,
-					   resultTupleSlot,
-					   InvalidBuffer,
-					   true);
+		ExecStoreHeapTuple(setopstate->grp_firstTuple,
+						   resultTupleSlot,
+						   true);
 		setopstate->grp_firstTuple = NULL;	/* don't keep two pointers */
 
 		/* Initialize working state for a new input tuple group */
diff --git a/src/backend/executor/nodeTidscan.c b/src/backend/executor/nodeTidscan.c
index e207b1ffb5..0cb1946a3e 100644
--- a/src/backend/executor/nodeTidscan.c
+++ b/src/backend/executor/nodeTidscan.c
@@ -377,20 +377,18 @@ TidNext(TidScanState *node)
 		if (heap_fetch(heapRelation, snapshot, tuple, &buffer, false, NULL))
 		{
 			/*
-			 * store the scanned tuple in the scan tuple slot of the scan
+			 * Store the scanned tuple in the scan tuple slot of the scan
 			 * state.  Eventually we will only do this and not return a tuple.
-			 * Note: we pass 'false' because tuples returned by amgetnext are
-			 * pointers onto disk pages and were not created with palloc() and
-			 * so should not be pfree()'d.
 			 */
-			ExecStoreTuple(tuple,	/* tuple to store */
-						   slot,	/* slot to store in */
-						   buffer,	/* buffer associated with tuple  */
-						   false);	/* don't pfree */
+			ExecStoreBufferHeapTuple(tuple,	/* tuple to store */
+									 slot,	/* slot to store in */
+									 buffer);	/* buffer associated with
+												 * tuple */
 
 			/*
 			 * At this point we have an extra pin on the buffer, because
-			 * ExecStoreTuple incremented the pin count. Drop our local pin.
+			 * ExecStoreHeapTuple incremented the pin count. Drop our local
+			 * pin.
 			 */
 			ReleaseBuffer(buffer);
 
diff --git a/src/backend/partitioning/partbounds.c b/src/backend/partitioning/partbounds.c
index 4ed9920618..c94f73aadc 100644
--- a/src/backend/partitioning/partbounds.c
+++ b/src/backend/partitioning/partbounds.c
@@ -715,7 +715,7 @@ check_default_partition_contents(Relation parent, Relation default_rel,
 
 		while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
 		{
-			ExecStoreTuple(tuple, tupslot, InvalidBuffer, false);
+			ExecStoreHeapTuple(tuple, tupslot, false);
 			econtext->ecxt_scantuple = tupslot;
 
 			if (!ExecCheck(partqualstate, econtext))
diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c
index 2054abe653..42345f94d3 100644
--- a/src/backend/replication/logical/worker.c
+++ b/src/backend/replication/logical/worker.c
@@ -755,7 +755,7 @@ apply_handle_update(StringInfo s)
 	{
 		/* Process and store remote tuple in the slot */
 		oldctx = MemoryContextSwitchTo(GetPerTupleMemoryContext(estate));
-		ExecStoreTuple(localslot->tts_tuple, remoteslot, InvalidBuffer, false);
+		ExecStoreHeapTuple(localslot->tts_tuple, remoteslot, false);
 		slot_modify_cstrings(remoteslot, rel, newtup.values, newtup.changed);
 		MemoryContextSwitchTo(oldctx);
 
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index f1c78ffb65..b8c0e034ca 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -5607,7 +5607,7 @@ get_actual_variable_range(PlannerInfo *root, VariableStatData *vardata,
 										 indexscandir)) != NULL)
 				{
 					/* Extract the index column values from the heap tuple */
-					ExecStoreTuple(tup, slot, InvalidBuffer, false);
+					ExecStoreHeapTuple(tup, slot, false);
 					FormIndexDatum(indexInfo, slot, estate,
 								   values, isnull);
 
@@ -5640,7 +5640,7 @@ get_actual_variable_range(PlannerInfo *root, VariableStatData *vardata,
 										 -indexscandir)) != NULL)
 				{
 					/* Extract the index column values from the heap tuple */
-					ExecStoreTuple(tup, slot, InvalidBuffer, false);
+					ExecStoreHeapTuple(tup, slot, false);
 					FormIndexDatum(indexInfo, slot, estate,
 								   values, isnull);
 
diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c
index 9fb33b9035..a649dc54eb 100644
--- a/src/backend/utils/sort/tuplesort.c
+++ b/src/backend/utils/sort/tuplesort.c
@@ -3792,11 +3792,11 @@ comparetup_cluster(const SortTuple *a, const SortTuple *b,
 
 		ecxt_scantuple = GetPerTupleExprContext(state->estate)->ecxt_scantuple;
 
-		ExecStoreTuple(ltup, ecxt_scantuple, InvalidBuffer, false);
+		ExecStoreHeapTuple(ltup, ecxt_scantuple, false);
 		FormIndexDatum(state->indexInfo, ecxt_scantuple, state->estate,
 					   l_index_values, l_index_isnull);
 
-		ExecStoreTuple(rtup, ecxt_scantuple, InvalidBuffer, false);
+		ExecStoreHeapTuple(rtup, ecxt_scantuple, false);
 		FormIndexDatum(state->indexInfo, ecxt_scantuple, state->estate,
 					   r_index_values, r_index_isnull);
 
diff --git a/src/include/executor/tuptable.h b/src/include/executor/tuptable.h
index c51d89b0c0..43150d13b1 100644
--- a/src/include/executor/tuptable.h
+++ b/src/include/executor/tuptable.h
@@ -153,10 +153,12 @@ extern void ExecResetTupleTable(List *tupleTable, bool shouldFree);
 extern TupleTableSlot *MakeSingleTupleTableSlot(TupleDesc tupdesc);
 extern void ExecDropSingleTupleTableSlot(TupleTableSlot *slot);
 extern void ExecSetSlotDescriptor(TupleTableSlot *slot, TupleDesc tupdesc);
-extern TupleTableSlot *ExecStoreTuple(HeapTuple tuple,
-			   TupleTableSlot *slot,
-			   Buffer buffer,
-			   bool shouldFree);
+extern TupleTableSlot *ExecStoreHeapTuple(HeapTuple tuple,
+				   TupleTableSlot *slot,
+				   bool shouldFree);
+extern TupleTableSlot *ExecStoreBufferHeapTuple(HeapTuple tuple,
+						 TupleTableSlot *slot,
+						 Buffer buffer);
 extern TupleTableSlot *ExecStoreMinimalTuple(MinimalTuple mtup,
 					  TupleTableSlot *slot,
 					  bool shouldFree);
-- 
2.40.0