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[PATCH v12 1/5] Allow CREATE INDEX CONCURRENTLY on partitioned table
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* [PATCH v12 1/5] Allow CREATE INDEX CONCURRENTLY on partitioned table
@ 2020-06-06 22:42  Justin Pryzby <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Justin Pryzby @ 2020-06-06 22:42 UTC (permalink / raw)

Note, this effectively reverts 050098b14, so take care to not reintroduce the
bug it fixed.

XXX: does pgstat_progress_update_param() break other commands progress ?
---
 doc/src/sgml/ref/create_index.sgml     |   9 --
 src/backend/commands/indexcmds.c       | 142 ++++++++++++++++++-------
 src/test/regress/expected/indexing.out |  60 ++++++++++-
 src/test/regress/sql/indexing.sql      |  18 +++-
 4 files changed, 173 insertions(+), 56 deletions(-)

diff --git a/doc/src/sgml/ref/create_index.sgml b/doc/src/sgml/ref/create_index.sgml
index a5271a9f8f..6869a18968 100644
--- a/doc/src/sgml/ref/create_index.sgml
+++ b/doc/src/sgml/ref/create_index.sgml
@@ -686,15 +686,6 @@ Indexes:
     cannot.
    </para>
 
-   <para>
-    Concurrent builds for indexes on partitioned tables are currently not
-    supported.  However, you may concurrently build the index on each
-    partition individually and then finally create the partitioned index
-    non-concurrently in order to reduce the time where writes to the
-    partitioned table will be locked out.  In this case, building the
-    partitioned index is a metadata only operation.
-   </para>
-
   </refsect2>
  </refsect1>
 
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index f9f3ff3b62..c513e8a6bd 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -68,6 +68,7 @@
 
 
 /* non-export function prototypes */
+static void reindex_invalid_child_indexes(Oid indexRelationId);
 static bool CompareOpclassOptions(Datum *opts1, Datum *opts2, int natts);
 static void CheckPredicate(Expr *predicate);
 static void ComputeIndexAttrs(IndexInfo *indexInfo,
@@ -680,17 +681,6 @@ DefineIndex(Oid relationId,
 	partitioned = rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE;
 	if (partitioned)
 	{
-		/*
-		 * Note: we check 'stmt->concurrent' rather than 'concurrent', so that
-		 * the error is thrown also for temporary tables.  Seems better to be
-		 * consistent, even though we could do it on temporary table because
-		 * we're not actually doing it concurrently.
-		 */
-		if (stmt->concurrent)
-			ereport(ERROR,
-					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-					 errmsg("cannot create index on partitioned table \"%s\" concurrently",
-							RelationGetRelationName(rel))));
 		if (stmt->excludeOpNames)
 			ereport(ERROR,
 					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -1128,6 +1118,11 @@ DefineIndex(Oid relationId,
 		if (pd->nparts != 0)
 			flags |= INDEX_CREATE_INVALID;
 	}
+	else if (concurrent && OidIsValid(parentIndexId))
+	{
+		/* If concurrent, initially build index partitions as "invalid" */
+		flags |= INDEX_CREATE_INVALID;
+	}
 
 	if (stmt->deferrable)
 		constr_flags |= INDEX_CONSTR_CREATE_DEFERRABLE;
@@ -1183,18 +1178,29 @@ DefineIndex(Oid relationId,
 		partdesc = RelationGetPartitionDesc(rel);
 		if ((!stmt->relation || stmt->relation->inh) && partdesc->nparts > 0)
 		{
+			/*
+			 * Need to close the relation before recursing into children, so
+			 * copy needed data into a longlived context.
+			 */
+
+			MemoryContext	ind_context = AllocSetContextCreate(PortalContext, "CREATE INDEX",
+					ALLOCSET_DEFAULT_SIZES);
+			MemoryContext	oldcontext = MemoryContextSwitchTo(ind_context);
 			int			nparts = partdesc->nparts;
 			Oid		   *part_oids = palloc(sizeof(Oid) * nparts);
 			bool		invalidate_parent = false;
 			TupleDesc	parentDesc;
 			Oid		   *opfamOids;
 
+			// If concurrent, maybe this should be done after excluding indexes which already exist ?
 			pgstat_progress_update_param(PROGRESS_CREATEIDX_PARTITIONS_TOTAL,
 										 nparts);
 
 			memcpy(part_oids, partdesc->oids, sizeof(Oid) * nparts);
+			parentDesc = CreateTupleDescCopy(RelationGetDescr(rel));
+			table_close(rel, NoLock);
+			MemoryContextSwitchTo(oldcontext);
 
-			parentDesc = RelationGetDescr(rel);
 			opfamOids = palloc(sizeof(Oid) * numberOfKeyAttributes);
 			for (i = 0; i < numberOfKeyAttributes; i++)
 				opfamOids[i] = get_opclass_family(classObjectId[i]);
@@ -1237,10 +1243,12 @@ DefineIndex(Oid relationId,
 					continue;
 				}
 
+				oldcontext = MemoryContextSwitchTo(ind_context);
 				childidxs = RelationGetIndexList(childrel);
 				attmap =
 					build_attrmap_by_name(RelationGetDescr(childrel),
 										  parentDesc);
+				MemoryContextSwitchTo(oldcontext);
 
 				foreach(cell, childidxs)
 				{
@@ -1311,10 +1319,14 @@ DefineIndex(Oid relationId,
 				 */
 				if (!found)
 				{
-					IndexStmt  *childStmt = copyObject(stmt);
+					IndexStmt  *childStmt;
 					bool		found_whole_row;
 					ListCell   *lc;
 
+					oldcontext = MemoryContextSwitchTo(ind_context);
+					childStmt = copyObject(stmt);
+					MemoryContextSwitchTo(oldcontext);
+
 					/*
 					 * We can't use the same index name for the child index,
 					 * so clear idxname to let the recursive invocation choose
@@ -1366,10 +1378,18 @@ DefineIndex(Oid relationId,
 								createdConstraintId,
 								is_alter_table, check_rights, check_not_in_use,
 								skip_build, quiet);
+					if (concurrent)
+					{
+						PopActiveSnapshot();
+						PushActiveSnapshot(GetTransactionSnapshot());
+						invalidate_parent = true;
+					}
 				}
 
-				pgstat_progress_update_param(PROGRESS_CREATEIDX_PARTITIONS_DONE,
-											 i + 1);
+				/* For concurrent build, this is a catalog-only stage */
+				if (!concurrent)
+					pgstat_progress_update_param(PROGRESS_CREATEIDX_PARTITIONS_DONE,
+												 i + 1);
 				free_attrmap(attmap);
 			}
 
@@ -1379,51 +1399,42 @@ DefineIndex(Oid relationId,
 			 * invalid, this is incorrect, so update our row to invalid too.
 			 */
 			if (invalidate_parent)
-			{
-				Relation	pg_index = table_open(IndexRelationId, RowExclusiveLock);
-				HeapTuple	tup,
-							newtup;
-
-				tup = SearchSysCache1(INDEXRELID,
-									  ObjectIdGetDatum(indexRelationId));
-				if (!HeapTupleIsValid(tup))
-					elog(ERROR, "cache lookup failed for index %u",
-						 indexRelationId);
-				newtup = heap_copytuple(tup);
-				((Form_pg_index) GETSTRUCT(newtup))->indisvalid = false;
-				CatalogTupleUpdate(pg_index, &tup->t_self, newtup);
-				ReleaseSysCache(tup);
-				table_close(pg_index, RowExclusiveLock);
-				heap_freetuple(newtup);
-			}
-		}
+				index_set_state_flags(indexRelationId, INDEX_DROP_CLEAR_VALID);
+		} else
+			table_close(rel, NoLock);
 
 		/*
 		 * Indexes on partitioned tables are not themselves built, so we're
 		 * done here.
 		 */
-		table_close(rel, NoLock);
 		if (!OidIsValid(parentIndexId))
+		{
+			if (concurrent)
+				reindex_invalid_child_indexes(indexRelationId);
+
 			pgstat_progress_end_command();
+		}
+
 		return address;
 	}
 
-	if (!concurrent)
+	table_close(rel, NoLock);
+	if (!concurrent || OidIsValid(parentIndexId))
 	{
-		/* Close the heap and we're done, in the non-concurrent case */
-		table_close(rel, NoLock);
+		/*
+		 * We're done if this is the top-level index,
+		 * or the catalog-only phase of a partition built concurrently
+		 */
 
-		/* If this is the top-level index, we're done. */
 		if (!OidIsValid(parentIndexId))
 			pgstat_progress_end_command();
 
 		return address;
 	}
 
-	/* save lockrelid and locktag for below, then close rel */
+	/* save lockrelid and locktag for below */
 	heaprelid = rel->rd_lockInfo.lockRelId;
 	SET_LOCKTAG_RELATION(heaplocktag, heaprelid.dbId, heaprelid.relId);
-	table_close(rel, NoLock);
 
 	/*
 	 * For a concurrent build, it's important to make the catalog entries
@@ -1617,6 +1628,57 @@ DefineIndex(Oid relationId,
 	return address;
 }
 
+/* Reindex invalid child indexes created earlier */
+static void
+reindex_invalid_child_indexes(Oid indexRelationId)
+{
+	ListCell *lc;
+	int		npart = 0;
+	ReindexParams params = { .options = REINDEXOPT_CONCURRENTLY };
+
+	MemoryContext	ind_context = AllocSetContextCreate(PortalContext, "CREATE INDEX",
+			ALLOCSET_DEFAULT_SIZES);
+	MemoryContext	oldcontext;
+	List		*childs = find_inheritance_children(indexRelationId, ShareLock);
+	List		*partitions = NIL;
+
+	PreventInTransactionBlock(true, "REINDEX INDEX");
+
+	foreach (lc, childs)
+	{
+		Oid			partoid = lfirst_oid(lc);
+
+		pgstat_progress_update_param(PROGRESS_CREATEIDX_PARTITIONS_DONE,
+									 npart++);
+
+		if (get_index_isvalid(partoid) ||
+				!RELKIND_HAS_STORAGE(get_rel_relkind(partoid)))
+			continue;
+
+		/* Save partition OID */
+		oldcontext = MemoryContextSwitchTo(ind_context);
+		partitions = lappend_oid(partitions, partoid);
+		MemoryContextSwitchTo(oldcontext);
+	}
+
+	/*
+	 * Process each partition listed in a separate transaction.  Note that
+	 * this commits and then starts a new transaction immediately.
+	 */
+	ReindexMultipleInternal(partitions, &params);
+
+	/*
+	 * CIC needs to mark a partitioned index as VALID, which itself
+	 * requires setting READY, which is unset for CIC (even though
+	 * it's meaningless for an index without storage).
+	 * This must be done only while holding a lock which precludes adding
+	 * partitions.
+	 * See also: validatePartitionedIndex().
+	 */
+	index_set_state_flags(indexRelationId, INDEX_CREATE_SET_READY);
+	CommandCounterIncrement();
+	index_set_state_flags(indexRelationId, INDEX_CREATE_SET_VALID);
+}
 
 /*
  * CheckMutability
diff --git a/src/test/regress/expected/indexing.out b/src/test/regress/expected/indexing.out
index c93f4470c9..f04abc6897 100644
--- a/src/test/regress/expected/indexing.out
+++ b/src/test/regress/expected/indexing.out
@@ -50,11 +50,63 @@ select relname, relkind, relhassubclass, inhparent::regclass
 (8 rows)
 
 drop table idxpart;
--- Some unsupported features
+-- CIC on partitioned table
 create table idxpart (a int, b int, c text) partition by range (a);
-create table idxpart1 partition of idxpart for values from (0) to (10);
-create index concurrently on idxpart (a);
-ERROR:  cannot create index on partitioned table "idxpart" concurrently
+create table idxpart1 partition of idxpart for values from (0) to (10) partition by range(a);
+create table idxpart11 partition of idxpart1 for values from (0) to (10) partition by range(a);
+create table idxpart111 partition of idxpart11 default partition by range(a);
+create table idxpart1111 partition of idxpart111 default partition by range(a);
+create table idxpart2 partition of idxpart for values from (10) to (20);
+insert into idxpart2 values(10),(10); -- not unique
+create index concurrently on idxpart (a); -- partitioned
+create index concurrently on idxpart1 (a); -- partitioned and partition
+create index concurrently on idxpart11 (a); -- partitioned and partition, with no leaves
+create index concurrently on idxpart2 (a); -- leaf
+create unique index concurrently on idxpart (a); -- partitioned, unique failure
+ERROR:  could not create unique index "idxpart2_a_idx2_ccnew"
+DETAIL:  Key (a)=(10) is duplicated.
+\d idxpart
+        Partitioned table "public.idxpart"
+ Column |  Type   | Collation | Nullable | Default 
+--------+---------+-----------+----------+---------
+ a      | integer |           |          | 
+ b      | integer |           |          | 
+ c      | text    |           |          | 
+Partition key: RANGE (a)
+Indexes:
+    "idxpart_a_idx" btree (a)
+    "idxpart_a_idx1" UNIQUE, btree (a) INVALID
+Number of partitions: 2 (Use \d+ to list them.)
+
+\d idxpart1
+        Partitioned table "public.idxpart1"
+ Column |  Type   | Collation | Nullable | Default 
+--------+---------+-----------+----------+---------
+ a      | integer |           |          | 
+ b      | integer |           |          | 
+ c      | text    |           |          | 
+Partition of: idxpart FOR VALUES FROM (0) TO (10)
+Partition key: RANGE (a)
+Indexes:
+    "idxpart1_a_idx" btree (a) INVALID
+    "idxpart1_a_idx1" btree (a)
+    "idxpart1_a_idx2" UNIQUE, btree (a) INVALID
+Number of partitions: 1 (Use \d+ to list them.)
+
+\d idxpart2
+              Table "public.idxpart2"
+ Column |  Type   | Collation | Nullable | Default 
+--------+---------+-----------+----------+---------
+ a      | integer |           |          | 
+ b      | integer |           |          | 
+ c      | text    |           |          | 
+Partition of: idxpart FOR VALUES FROM (10) TO (20)
+Indexes:
+    "idxpart2_a_idx" btree (a)
+    "idxpart2_a_idx1" btree (a)
+    "idxpart2_a_idx2" UNIQUE, btree (a) INVALID
+    "idxpart2_a_idx2_ccnew" UNIQUE, btree (a) INVALID
+
 drop table idxpart;
 -- Verify bugfix with query on indexed partitioned table with no partitions
 -- https://postgr.es/m/[email protected]
diff --git a/src/test/regress/sql/indexing.sql b/src/test/regress/sql/indexing.sql
index 42f398b67c..3d4b6e9bc9 100644
--- a/src/test/regress/sql/indexing.sql
+++ b/src/test/regress/sql/indexing.sql
@@ -29,10 +29,22 @@ select relname, relkind, relhassubclass, inhparent::regclass
 	where relname like 'idxpart%' order by relname;
 drop table idxpart;
 
--- Some unsupported features
+-- CIC on partitioned table
 create table idxpart (a int, b int, c text) partition by range (a);
-create table idxpart1 partition of idxpart for values from (0) to (10);
-create index concurrently on idxpart (a);
+create table idxpart1 partition of idxpart for values from (0) to (10) partition by range(a);
+create table idxpart11 partition of idxpart1 for values from (0) to (10) partition by range(a);
+create table idxpart111 partition of idxpart11 default partition by range(a);
+create table idxpart1111 partition of idxpart111 default partition by range(a);
+create table idxpart2 partition of idxpart for values from (10) to (20);
+insert into idxpart2 values(10),(10); -- not unique
+create index concurrently on idxpart (a); -- partitioned
+create index concurrently on idxpart1 (a); -- partitioned and partition
+create index concurrently on idxpart11 (a); -- partitioned and partition, with no leaves
+create index concurrently on idxpart2 (a); -- leaf
+create unique index concurrently on idxpart (a); -- partitioned, unique failure
+\d idxpart
+\d idxpart1
+\d idxpart2
 drop table idxpart;
 
 -- Verify bugfix with query on indexed partitioned table with no partitions
-- 
2.17.0


--MfFXiAuoTsnnDAfZ
Content-Type: text/x-diff; charset=us-ascii
Content-Disposition: attachment;
 filename="v12-0002-Add-SKIPVALID-flag-for-more-integration.patch"



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



^ permalink  raw  reply  [nested|flat] 300+ messages in thread

* [PATCH 1/8] Use tuple slot to pass tuples for rewriting.
@ 2026-06-16 11:54  Antonin Houska <[email protected]>
  0 siblings, 0 replies; 300+ messages in thread

From: Antonin Houska @ 2026-06-16 11:54 UTC (permalink / raw)

This patch tries to adopt the preferable way of handling tuples, i.e. pass the
containing tuple slot rather than the actual tuple. The motivation is that
heap_insert_for_repack() will need a slot in the near future, in order to call
ExecInsertIndexTuples(). Also, in order to set values of dropped attributes to
to NULL, it seems more compact to pass a tuple slot as a workspace than two
arrays (one for values and one for nulls).
---
 src/backend/access/heap/heapam_handler.c | 199 +++++++++++++----------
 1 file changed, 110 insertions(+), 89 deletions(-)

diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index 2268cc277bc..127d4415084 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -48,14 +48,13 @@
 #include "utils/rel.h"
 #include "utils/tuplesort.h"
 
-static void reform_and_rewrite_tuple(HeapTuple tuple,
-									 Relation OldHeap, Relation NewHeap,
-									 Datum *values, bool *isnull, RewriteState rwstate);
-static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
-								   Relation NewHeap, Datum *values, bool *isnull,
-								   BulkInsertState bistate);
-static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
-							  Relation NewHeap, Datum *values, bool *isnull);
+static void reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+									 RewriteState rwstate);
+static void heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+								   TupleTableSlot *reform,
+								   BulkInsertStateData *bistate);
+static bool tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc);
+static void clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform);
 
 static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
 								   HeapTuple tuple,
@@ -609,11 +608,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	bool		is_system_catalog;
 	Tuplesortstate *tuplesort;
 	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
 	TupleTableSlot *slot;
-	int			natts;
-	Datum	   *values;
-	bool	   *isnull;
+	TupleTableSlot *reform_slot;
 	BufferHeapTupleTableSlot *hslot;
 	BlockNumber prev_cblock = InvalidBlockNumber;
 	bool		concurrent = snapshot != NULL;
@@ -627,11 +623,6 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 	 */
 	Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
 
-	/* Preallocate values/isnull arrays */
-	natts = newTupDesc->natts;
-	values = palloc_array(Datum, natts);
-	isnull = palloc_array(bool, natts);
-
 	/*
 	 * In non-concurrent mode, initialize the rewrite operation.  This is not
 	 * needed in concurrent mode.
@@ -705,6 +696,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 
 	slot = table_slot_create(OldHeap, NULL);
 	hslot = (BufferHeapTupleTableSlot *) slot;
+	reform_slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										   &TTSOpsVirtual);
 
 	/*
 	 * Scan through the OldHeap, either in OldIndex order or sequentially;
@@ -881,11 +874,9 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			int64		ct_val[2];
 
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
-										 values, isnull, rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/*
 			 * In indexscan mode and also VACUUM FULL, report increase in
@@ -901,8 +892,7 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		index_endscan(indexScan);
 	if (tableScan != NULL)
 		table_endscan(tableScan);
-	if (slot)
-		ExecDropSingleTupleTableSlot(slot);
+	ExecDropSingleTupleTableSlot(slot);
 
 	/*
 	 * In scan-and-sort mode, complete the sort, then read out all live tuples
@@ -922,6 +912,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 		pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
 									 PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP);
 
+		slot = MakeSingleTupleTableSlot(RelationGetDescr(OldHeap),
+										&TTSOpsHeapTuple);
 		for (;;)
 		{
 			HeapTuple	tuple;
@@ -932,33 +924,36 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
 			if (tuple == NULL)
 				break;
 
+			/*
+			 * XXX Ideally we should use tuplesort_gettupleslot() above, but
+			 * it retrieves minimal tuples and tuplesort_puttupleslot() cannot
+			 * get the tuple descriptor from tuplesort created by
+			 * tuplesort_begin_cluster().
+			 */
+			ExecStoreHeapTuple(tuple, slot, false);
+
 			n_tuples += 1;
 			if (!concurrent)
-				reform_and_rewrite_tuple(tuple,
-										 OldHeap, NewHeap,
-										 values, isnull,
-										 rwstate);
+				reform_and_rewrite_tuple(slot, reform_slot, rwstate);
 			else
-				heap_insert_for_repack(tuple, OldHeap, NewHeap,
-									   values, isnull, bistate);
+				heap_insert_for_repack(NewHeap, slot, reform_slot, bistate);
 
 			/* Report n_tuples */
 			pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
 										 n_tuples);
 		}
 
+		ExecDropSingleTupleTableSlot(slot);
 		tuplesort_end(tuplesort);
 	}
 
+	ExecDropSingleTupleTableSlot(reform_slot);
+
 	/* Write out any remaining tuples, and fsync if needed */
 	if (rwstate)
 		end_heap_rewrite(rwstate);
 	if (bistate)
 		FreeBulkInsertState(bistate);
-
-	/* Clean up */
-	pfree(values);
-	pfree(isnull);
 }
 
 /*
@@ -2346,21 +2341,45 @@ heapam_scan_sample_next_tuple(TableScanDesc scan, SampleScanState *scanstate,
  * currently only known to happen as an after-effect of ALTER TABLE
  * SET WITHOUT OIDS.
  *
- * So, we must reconstruct the tuple from component Datums.
+ * So, we must reconstruct the tuple from component Datums. 'reform' slot
+ * is a workspace for this reconstruction.
  */
 static void
-reform_and_rewrite_tuple(HeapTuple tuple,
-						 Relation OldHeap, Relation NewHeap,
-						 Datum *values, bool *isnull, RewriteState rwstate)
+reform_and_rewrite_tuple(TupleTableSlot *src, TupleTableSlot *reform,
+						 RewriteState rwstate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple,
+				newtuple;
+	bool		shouldFree,
+				shouldFreeNew;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	/*
+	 * The old tuple will not be modified, so do not request materialization.
+	 * (A copy can be created for specific slot type though, e.g.
+	 * TTSOpsMinimalTuple.)
+	 */
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+
+		/* No need to materialize, copy will be created anyway. */
+		Assert(TTS_IS_VIRTUAL(reform));
+		newtuple = ExecFetchSlotHeapTuple(reform, false, &shouldFreeNew);
+	}
+	else
+	{
+		newtuple = heap_copytuple(tuple);
+		shouldFreeNew = true;
+	}
 
 	/* The heap rewrite module does the rest */
 	rewrite_heap_tuple(rwstate, tuple, newtuple);
 
-	heap_freetuple(newtuple);
+	if (shouldFree)
+		heap_freetuple(tuple);
+	if (shouldFreeNew)
+		heap_freetuple(newtuple);
 }
 
 /*
@@ -2372,6 +2391,9 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * information). Thus we must use heap_insert() both during the
  * catch-up and here.
  *
+ * 'reform' is a slot to use for tuple "reforming", typically to get set
+ * values of dropped columns to NULL.
+ *
  * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
  * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
  * this relation, so no logical replication subscription should need the data.
@@ -2380,76 +2402,75 @@ reform_and_rewrite_tuple(HeapTuple tuple,
  * case.
  */
 static void
-heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-					   Datum *values, bool *isnull, BulkInsertState bistate)
+heap_insert_for_repack(Relation rel, TupleTableSlot *src,
+					   TupleTableSlot *reform, BulkInsertStateData *bistate)
 {
-	HeapTuple	newtuple;
+	HeapTuple	tuple;
+	bool		shouldFree;
+	TupleTableSlot *slot;
 
-	newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+	tuple = ExecFetchSlotHeapTuple(src, false, &shouldFree);
+	if (tuple_needs_reform(tuple, src->tts_tupleDescriptor))
+	{
+		clear_dropped_attributes(tuple, reform);
+		slot = reform;
+	}
+	else
+		slot = src;
 
-	heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
-				HEAP_INSERT_NO_LOGICAL, bistate);
+	/*
+	 * clear_dropped_attributes() should have deformed the tuple, so nothing
+	 * should depend on it now.
+	 */
+	if (shouldFree)
+		heap_freetuple(tuple);
 
-	heap_freetuple(newtuple);
+	table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+					   TABLE_INSERT_NO_LOGICAL, bistate);
 }
 
-/*
- * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
- *
- * Deform the given tuple, set values of dropped columns to NULL, and fill in
- * any values from attmissingval; then form a new tuple and return it.  If no
- * attributes need to be changed, a copy of the original tuple is returned.
- * Caller is responsible for freeing the returned tuple.
- *
- * XXX this coding assumes that both relations have the same tupledesc.
- */
-static HeapTuple
-reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
-			 Datum *values, bool *isnull)
+static bool
+tuple_needs_reform(HeapTuple tuple, TupleDesc tupDesc)
 {
-	TupleDesc	oldTupDesc = RelationGetDescr(OldHeap);
-	TupleDesc	newTupDesc = RelationGetDescr(NewHeap);
-	bool		needs_reform = false;
-
 	/*
 	 * A short tuple might require values from attmissing val, so activate the
 	 * coding unconditionally in that case.  The value might legitimally be
 	 * NULL otherwise, so this is slightly wasteful, but it probably beats
 	 * having to test each attribute for presence of attmissingval each time.
 	 */
-	if (HeapTupleHeaderGetNatts(tuple->t_data) < newTupDesc->natts)
-		needs_reform = true;
+	if (HeapTupleHeaderGetNatts(tuple->t_data) < tupDesc->natts)
+		return true;
 
-	/*
-	 * If the column has been dropped but a value is still present, we can
-	 * optimize storage now by getting rid of it.
-	 */
-	if (!needs_reform)
+	/* Does it have dropped attributes? */
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		for (int i = 0; i < newTupDesc->natts; i++)
-		{
-			if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
-				!heap_attisnull(tuple, i + 1, newTupDesc))
-			{
-				needs_reform = true;
-				break;
-			}
-		}
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped &&
+			!heap_attisnull(tuple, i + 1, tupDesc))
+			return true;
 	}
 
-	/* Skip work if no changes are needed */
-	if (!needs_reform)
-		return heap_copytuple(tuple);
+	return false;
+}
 
-	heap_deform_tuple(tuple, oldTupDesc, values, isnull);
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Set values of dropped columns to NULL,
+ */
+static void
+clear_dropped_attributes(HeapTuple tuple, TupleTableSlot *reform)
+{
+	TupleDesc	tupDesc = reform->tts_tupleDescriptor;
+
+	/* Assuming 'reform' is virtual, this deforms the tuple. */
+	Assert(TTS_IS_VIRTUAL(reform));
+	ExecForceStoreHeapTuple(tuple, reform, false);
 
-	for (int i = 0; i < newTupDesc->natts; i++)
+	for (int i = 0; i < tupDesc->natts; i++)
 	{
-		if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
-			isnull[i] = true;
+		if (TupleDescCompactAttr(tupDesc, i)->attisdropped)
+			reform->tts_isnull[i] = true;
 	}
-
-	return heap_form_tuple(newTupDesc, values, isnull);
 }
 
 /*
-- 
2.52.0


--=-=-=
Content-Type: text/x-diff
Content-Disposition: attachment;
 filename=v01-0002-Move-functions-to-repack.c.patch



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