From b238e9c4308e9f2b7f0f2ca068b1217d1f906604 Mon Sep 17 00:00:00 2001
From: Matthias van de Meent <boekewurm+postgres@gmail.com>
Date: Mon, 20 Feb 2023 18:38:30 +0100
Subject: [PATCH v3 1/2] Ignore BRIN indexes when checking for HOT updates

When determining whether an index update may be skipped by using HOT, we
can ignore attributes indexed by block summarizing indexes without
references to individual tuples that need to be cleaned up.

This also removes rd_indexattr list, and replaces it with rd_attrsvalid
flag. The list was not used anywhere, and a simple flag is sufficient.

A new type TU_UpdateIndexes is invented provide a signal to the executor
to determine which indexes to update - no indexes, all indexes, or only
the summarizing indexes.

One otherwise unused bit in the heap tuple header is (ab)used to signal
that the HOT update would still update at least one summarizing index.
The bit is cleared immediately

Original patch by Josef Simanek, various fixes and improvements by
Tomas Vondra and me.

Authors: Josef Simanek, Tomas Vondra, Matthias van de Meent
Reviewed-by: Tomas Vondra, Alvaro Herrera
---
 doc/src/sgml/indexam.sgml                     |  13 +++
 src/backend/access/brin/brin.c                |   1 +
 src/backend/access/gin/ginutil.c              |   1 +
 src/backend/access/gist/gist.c                |   1 +
 src/backend/access/hash/hash.c                |   1 +
 src/backend/access/heap/heapam.c              |  48 +++++++-
 src/backend/access/heap/heapam_handler.c      |  19 ++-
 src/backend/access/nbtree/nbtree.c            |   1 +
 src/backend/access/spgist/spgutils.c          |   1 +
 src/backend/access/table/tableam.c            |   2 +-
 src/backend/catalog/index.c                   |   9 +-
 src/backend/catalog/indexing.c                |  35 ++++--
 src/backend/commands/copyfrom.c               |   5 +-
 src/backend/commands/indexcmds.c              |  10 +-
 src/backend/executor/execIndexing.c           |  37 ++++--
 src/backend/executor/execReplication.c        |   9 +-
 src/backend/executor/nodeModifyTable.c        |  13 ++-
 src/backend/nodes/makefuncs.c                 |   7 +-
 src/backend/utils/cache/relcache.c            |  73 ++++++++----
 src/include/access/amapi.h                    |   2 +
 src/include/access/heapam.h                   |   5 +-
 src/include/access/tableam.h                  |  19 ++-
 src/include/executor/executor.h               |   3 +-
 src/include/nodes/execnodes.h                 |   2 +
 src/include/nodes/makefuncs.h                 |   4 +-
 src/include/utils/rel.h                       |   4 +-
 src/include/utils/relcache.h                  |   5 +-
 .../modules/dummy_index_am/dummy_index_am.c   |   1 +
 src/test/regress/expected/stats.out           | 110 ++++++++++++++++++
 src/test/regress/sql/stats.sql                |  82 ++++++++++++-
 30 files changed, 445 insertions(+), 78 deletions(-)

diff --git a/doc/src/sgml/indexam.sgml b/doc/src/sgml/indexam.sgml
index 4f83970c851..897419ec959 100644
--- a/doc/src/sgml/indexam.sgml
+++ b/doc/src/sgml/indexam.sgml
@@ -127,6 +127,9 @@ typedef struct IndexAmRoutine
     bool        amcaninclude;
     /* does AM use maintenance_work_mem? */
     bool        amusemaintenanceworkmem;
+    /* does AM summarize tuples, with at least all tuples in the block
+     * summarized in one summary */
+    bool        amsummarizing;
     /* OR of parallel vacuum flags */
     uint8       amparallelvacuumoptions;
     /* type of data stored in index, or InvalidOid if variable */
@@ -247,6 +250,16 @@ typedef struct IndexAmRoutine
    null, independently of <structfield>amoptionalkey</structfield>.
   </para>
 
+  <para>
+   The <structfield>amsummarizing</structfield> flag indicates whether the
+   access method summarizes the indexed tuples, with summarizing granularity
+   of at least per block.
+   Access methods that do not point to individual tuples, but to  (like
+   <acronym>BRIN</acronym>), may allow the <acronym>HOT</acronym> optimization
+   to continue. This does not apply to attributes referenced in index
+   predicates, an update of such attribute always disables <acronym>HOT</acronym>.
+  </para>
+
  </sect1>
 
  <sect1 id="index-functions">
diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index b5a5fa7b334..53e4721a54e 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -109,6 +109,7 @@ brinhandler(PG_FUNCTION_ARGS)
 	amroutine->amcanparallel = false;
 	amroutine->amcaninclude = false;
 	amroutine->amusemaintenanceworkmem = false;
+	amroutine->amsummarizing = true;
 	amroutine->amparallelvacuumoptions =
 		VACUUM_OPTION_PARALLEL_CLEANUP;
 	amroutine->amkeytype = InvalidOid;
diff --git a/src/backend/access/gin/ginutil.c b/src/backend/access/gin/ginutil.c
index f05128ecf50..03fec1704e9 100644
--- a/src/backend/access/gin/ginutil.c
+++ b/src/backend/access/gin/ginutil.c
@@ -56,6 +56,7 @@ ginhandler(PG_FUNCTION_ARGS)
 	amroutine->amcanparallel = false;
 	amroutine->amcaninclude = false;
 	amroutine->amusemaintenanceworkmem = true;
+	amroutine->amsummarizing = false;
 	amroutine->amparallelvacuumoptions =
 		VACUUM_OPTION_PARALLEL_BULKDEL | VACUUM_OPTION_PARALLEL_CLEANUP;
 	amroutine->amkeytype = InvalidOid;
diff --git a/src/backend/access/gist/gist.c b/src/backend/access/gist/gist.c
index ba394f08f61..ea72bcce1bc 100644
--- a/src/backend/access/gist/gist.c
+++ b/src/backend/access/gist/gist.c
@@ -78,6 +78,7 @@ gisthandler(PG_FUNCTION_ARGS)
 	amroutine->amcanparallel = false;
 	amroutine->amcaninclude = true;
 	amroutine->amusemaintenanceworkmem = false;
+	amroutine->amsummarizing = false;
 	amroutine->amparallelvacuumoptions =
 		VACUUM_OPTION_PARALLEL_BULKDEL | VACUUM_OPTION_PARALLEL_COND_CLEANUP;
 	amroutine->amkeytype = InvalidOid;
diff --git a/src/backend/access/hash/hash.c b/src/backend/access/hash/hash.c
index eb258337d69..fc5d97f606e 100644
--- a/src/backend/access/hash/hash.c
+++ b/src/backend/access/hash/hash.c
@@ -75,6 +75,7 @@ hashhandler(PG_FUNCTION_ARGS)
 	amroutine->amcanparallel = false;
 	amroutine->amcaninclude = false;
 	amroutine->amusemaintenanceworkmem = false;
+	amroutine->amsummarizing = false;
 	amroutine->amparallelvacuumoptions =
 		VACUUM_OPTION_PARALLEL_BULKDEL;
 	amroutine->amkeytype = INT4OID;
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index 7eb79cee58d..89fdfe53532 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -2924,11 +2924,13 @@ simple_heap_delete(Relation relation, ItemPointer tid)
 TM_Result
 heap_update(Relation relation, ItemPointer otid, HeapTuple newtup,
 			CommandId cid, Snapshot crosscheck, bool wait,
-			TM_FailureData *tmfd, LockTupleMode *lockmode)
+			TM_FailureData *tmfd, LockTupleMode *lockmode,
+			TU_UpdateIndexes *update_indexes)
 {
 	TM_Result	result;
 	TransactionId xid = GetCurrentTransactionId();
 	Bitmapset  *hot_attrs;
+	Bitmapset  *sum_attrs;
 	Bitmapset  *key_attrs;
 	Bitmapset  *id_attrs;
 	Bitmapset  *interesting_attrs;
@@ -2951,6 +2953,7 @@ heap_update(Relation relation, ItemPointer otid, HeapTuple newtup,
 	bool		have_tuple_lock = false;
 	bool		iscombo;
 	bool		use_hot_update = false;
+	bool		summarized_update = false;
 	bool		key_intact;
 	bool		all_visible_cleared = false;
 	bool		all_visible_cleared_new = false;
@@ -2996,12 +2999,16 @@ heap_update(Relation relation, ItemPointer otid, HeapTuple newtup,
 	 * Note that we get copies of each bitmap, so we need not worry about
 	 * relcache flush happening midway through.
 	 */
-	hot_attrs = RelationGetIndexAttrBitmap(relation, INDEX_ATTR_BITMAP_ALL);
+	hot_attrs = RelationGetIndexAttrBitmap(relation,
+										   INDEX_ATTR_BITMAP_HOT_BLOCKING);
+	sum_attrs = RelationGetIndexAttrBitmap(relation,
+										   INDEX_ATTR_BITMAP_SUMMARIZED);
 	key_attrs = RelationGetIndexAttrBitmap(relation, INDEX_ATTR_BITMAP_KEY);
 	id_attrs = RelationGetIndexAttrBitmap(relation,
 										  INDEX_ATTR_BITMAP_IDENTITY_KEY);
 	interesting_attrs = NULL;
 	interesting_attrs = bms_add_members(interesting_attrs, hot_attrs);
+	interesting_attrs = bms_add_members(interesting_attrs, sum_attrs);
 	interesting_attrs = bms_add_members(interesting_attrs, key_attrs);
 	interesting_attrs = bms_add_members(interesting_attrs, id_attrs);
 
@@ -3311,7 +3318,10 @@ l2:
 			UnlockTupleTuplock(relation, &(oldtup.t_self), *lockmode);
 		if (vmbuffer != InvalidBuffer)
 			ReleaseBuffer(vmbuffer);
+		*update_indexes = TU_None;
+
 		bms_free(hot_attrs);
+		bms_free(sum_attrs);
 		bms_free(key_attrs);
 		bms_free(id_attrs);
 		bms_free(modified_attrs);
@@ -3633,7 +3643,19 @@ l2:
 		 * changed.
 		 */
 		if (!bms_overlap(modified_attrs, hot_attrs))
+		{
 			use_hot_update = true;
+
+			/*
+			 * If none of the columns that are used in hot-blocking indexes
+			 * were updated, we can apply HOT, but we do still need to check
+			 * if we need to update the summarizing indexes, and update those
+			 * indexes if the columns were updated, or we may fail to detect
+			 * e.g. value bound changes in BRIN minmax indexes.
+			 */
+			if (bms_overlap(modified_attrs, sum_attrs))
+				summarized_update = true;
+		}
 	}
 	else
 	{
@@ -3793,10 +3815,27 @@ l2:
 		heap_freetuple(heaptup);
 	}
 
+	/*
+	 * If it is a HOT update, the update may still need to update summarized
+	 * indexes, lest we fail to update those summaries and get incorrect
+	 * results (for example, minmax bounds of the block may change with this
+	 * update).
+	 */
+	if (use_hot_update)
+	{
+		if (summarized_update)
+			*update_indexes = TU_Summarizing;
+		else
+			*update_indexes = TU_None;
+	}
+	else
+		*update_indexes = TU_All;
+
 	if (old_key_tuple != NULL && old_key_copied)
 		heap_freetuple(old_key_tuple);
 
 	bms_free(hot_attrs);
+	bms_free(sum_attrs);
 	bms_free(key_attrs);
 	bms_free(id_attrs);
 	bms_free(modified_attrs);
@@ -3960,7 +3999,8 @@ HeapDetermineColumnsInfo(Relation relation,
  * via ereport().
  */
 void
-simple_heap_update(Relation relation, ItemPointer otid, HeapTuple tup)
+simple_heap_update(Relation relation, ItemPointer otid, HeapTuple tup,
+				   TU_UpdateIndexes *update_indexes)
 {
 	TM_Result	result;
 	TM_FailureData tmfd;
@@ -3969,7 +4009,7 @@ simple_heap_update(Relation relation, ItemPointer otid, HeapTuple tup)
 	result = heap_update(relation, otid, tup,
 						 GetCurrentCommandId(true), InvalidSnapshot,
 						 true /* wait for commit */ ,
-						 &tmfd, &lockmode);
+						 &tmfd, &lockmode, update_indexes);
 	switch (result)
 	{
 		case TM_SelfModified:
diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c
index c4b1916d36e..a1d7d91ff77 100644
--- a/src/backend/access/heap/heapam_handler.c
+++ b/src/backend/access/heap/heapam_handler.c
@@ -314,7 +314,7 @@ static TM_Result
 heapam_tuple_update(Relation relation, ItemPointer otid, TupleTableSlot *slot,
 					CommandId cid, Snapshot snapshot, Snapshot crosscheck,
 					bool wait, TM_FailureData *tmfd,
-					LockTupleMode *lockmode, bool *update_indexes)
+					LockTupleMode *lockmode, TU_UpdateIndexes *update_indexes)
 {
 	bool		shouldFree = true;
 	HeapTuple	tuple = ExecFetchSlotHeapTuple(slot, true, &shouldFree);
@@ -325,7 +325,7 @@ heapam_tuple_update(Relation relation, ItemPointer otid, TupleTableSlot *slot,
 	tuple->t_tableOid = slot->tts_tableOid;
 
 	result = heap_update(relation, otid, tuple, cid, crosscheck, wait,
-						 tmfd, lockmode);
+						 tmfd, lockmode, update_indexes);
 	ItemPointerCopy(&tuple->t_self, &slot->tts_tid);
 
 	/*
@@ -334,9 +334,20 @@ heapam_tuple_update(Relation relation, ItemPointer otid, TupleTableSlot *slot,
 	 * Note: heap_update returns the tid (location) of the new tuple in the
 	 * t_self field.
 	 *
-	 * If it's a HOT update, we mustn't insert new index entries.
+	 * If the update is not HOT, we must update all indexes. If the update
+	 * is HOT, it could be that we updated summarized columns, so we either
+	 * update only summarized indexes, or none at all.
 	 */
-	*update_indexes = result == TM_Ok && !HeapTupleIsHeapOnly(tuple);
+	if (result != TM_Ok)
+	{
+		Assert(*update_indexes == TU_None);
+		*update_indexes = TU_None;
+	}
+	else if (!HeapTupleIsHeapOnly(tuple))
+		Assert(*update_indexes == TU_All);
+	else
+		Assert(*update_indexes == TU_Summarizing ||
+			   *update_indexes == TU_None);
 
 	if (shouldFree)
 		pfree(tuple);
diff --git a/src/backend/access/nbtree/nbtree.c b/src/backend/access/nbtree/nbtree.c
index 1cc88da032d..681c30b0d8d 100644
--- a/src/backend/access/nbtree/nbtree.c
+++ b/src/backend/access/nbtree/nbtree.c
@@ -114,6 +114,7 @@ bthandler(PG_FUNCTION_ARGS)
 	amroutine->amcanparallel = true;
 	amroutine->amcaninclude = true;
 	amroutine->amusemaintenanceworkmem = false;
+	amroutine->amsummarizing = false;
 	amroutine->amparallelvacuumoptions =
 		VACUUM_OPTION_PARALLEL_BULKDEL | VACUUM_OPTION_PARALLEL_COND_CLEANUP;
 	amroutine->amkeytype = InvalidOid;
diff --git a/src/backend/access/spgist/spgutils.c b/src/backend/access/spgist/spgutils.c
index 3761f2c193b..4e7ff1d1603 100644
--- a/src/backend/access/spgist/spgutils.c
+++ b/src/backend/access/spgist/spgutils.c
@@ -62,6 +62,7 @@ spghandler(PG_FUNCTION_ARGS)
 	amroutine->amcanparallel = false;
 	amroutine->amcaninclude = true;
 	amroutine->amusemaintenanceworkmem = false;
+	amroutine->amsummarizing = false;
 	amroutine->amparallelvacuumoptions =
 		VACUUM_OPTION_PARALLEL_BULKDEL | VACUUM_OPTION_PARALLEL_COND_CLEANUP;
 	amroutine->amkeytype = InvalidOid;
diff --git a/src/backend/access/table/tableam.c b/src/backend/access/table/tableam.c
index ef0d34fceee..a5e6c92f35e 100644
--- a/src/backend/access/table/tableam.c
+++ b/src/backend/access/table/tableam.c
@@ -345,7 +345,7 @@ void
 simple_table_tuple_update(Relation rel, ItemPointer otid,
 						  TupleTableSlot *slot,
 						  Snapshot snapshot,
-						  bool *update_indexes)
+						  TU_UpdateIndexes *update_indexes)
 {
 	TM_Result	result;
 	TM_FailureData tmfd;
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 41b16cb89bc..e2fd035f445 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1370,7 +1370,8 @@ index_concurrently_create_copy(Relation heapRelation, Oid oldIndexId,
 							oldInfo->ii_Unique,
 							oldInfo->ii_NullsNotDistinct,
 							false,	/* not ready for inserts */
-							true);
+							true,
+							indexRelation->rd_indam->amsummarizing);
 
 	/*
 	 * Extract the list of column names and the column numbers for the new
@@ -2442,7 +2443,8 @@ BuildIndexInfo(Relation index)
 					   indexStruct->indisunique,
 					   indexStruct->indnullsnotdistinct,
 					   indexStruct->indisready,
-					   false);
+					   false,
+					   index->rd_indam->amsummarizing);
 
 	/* fill in attribute numbers */
 	for (i = 0; i < numAtts; i++)
@@ -2502,7 +2504,8 @@ BuildDummyIndexInfo(Relation index)
 					   indexStruct->indisunique,
 					   indexStruct->indnullsnotdistinct,
 					   indexStruct->indisready,
-					   false);
+					   false,
+					   index->rd_indam->amsummarizing);
 
 	/* fill in attribute numbers */
 	for (i = 0; i < numAtts; i++)
diff --git a/src/backend/catalog/indexing.c b/src/backend/catalog/indexing.c
index bb7cc3601c7..a387eccdc40 100644
--- a/src/backend/catalog/indexing.c
+++ b/src/backend/catalog/indexing.c
@@ -72,7 +72,8 @@ CatalogCloseIndexes(CatalogIndexState indstate)
  * This is effectively a cut-down version of ExecInsertIndexTuples.
  */
 static void
-CatalogIndexInsert(CatalogIndexState indstate, HeapTuple heapTuple)
+CatalogIndexInsert(CatalogIndexState indstate, HeapTuple heapTuple,
+				   TU_UpdateIndexes updateIndexes)
 {
 	int			i;
 	int			numIndexes;
@@ -82,6 +83,7 @@ CatalogIndexInsert(CatalogIndexState indstate, HeapTuple heapTuple)
 	IndexInfo **indexInfoArray;
 	Datum		values[INDEX_MAX_KEYS];
 	bool		isnull[INDEX_MAX_KEYS];
+	bool		onlySummarized = updateIndexes == TU_Summarizing;
 
 	/*
 	 * HOT update does not require index inserts. But with asserts enabled we
@@ -89,10 +91,13 @@ CatalogIndexInsert(CatalogIndexState indstate, HeapTuple heapTuple)
 	 * table/index.
 	 */
 #ifndef USE_ASSERT_CHECKING
-	if (HeapTupleIsHeapOnly(heapTuple))
+	if (HeapTupleIsHeapOnly(heapTuple) && !onlySummarized)
 		return;
 #endif
 
+	if (onlySummarized)
+		Assert(HeapTupleIsHeapOnly(heapTuple));
+
 	/*
 	 * Get information from the state structure.  Fall out if nothing to do.
 	 */
@@ -135,13 +140,20 @@ CatalogIndexInsert(CatalogIndexState indstate, HeapTuple heapTuple)
 
 		/* see earlier check above */
 #ifdef USE_ASSERT_CHECKING
-		if (HeapTupleIsHeapOnly(heapTuple))
+		if (HeapTupleIsHeapOnly(heapTuple) && !onlySummarized)
 		{
 			Assert(!ReindexIsProcessingIndex(RelationGetRelid(index)));
 			continue;
 		}
 #endif							/* USE_ASSERT_CHECKING */
 
+		/*
+		 * Skip insertions into non-summarizing indexes if we only need
+		 * to update summarizing indexes
+		 */
+		if (onlySummarized && !indexInfo->ii_Summarizing)
+			continue;
+
 		/*
 		 * FormIndexDatum fills in its values and isnull parameters with the
 		 * appropriate values for the column(s) of the index.
@@ -228,7 +240,7 @@ CatalogTupleInsert(Relation heapRel, HeapTuple tup)
 
 	simple_heap_insert(heapRel, tup);
 
-	CatalogIndexInsert(indstate, tup);
+	CatalogIndexInsert(indstate, tup, TU_All);
 	CatalogCloseIndexes(indstate);
 }
 
@@ -248,7 +260,7 @@ CatalogTupleInsertWithInfo(Relation heapRel, HeapTuple tup,
 
 	simple_heap_insert(heapRel, tup);
 
-	CatalogIndexInsert(indstate, tup);
+	CatalogIndexInsert(indstate, tup, TU_All);
 }
 
 /*
@@ -279,7 +291,7 @@ CatalogTuplesMultiInsertWithInfo(Relation heapRel, TupleTableSlot **slot,
 
 		tuple = ExecFetchSlotHeapTuple(slot[i], true, &should_free);
 		tuple->t_tableOid = slot[i]->tts_tableOid;
-		CatalogIndexInsert(indstate, tuple);
+		CatalogIndexInsert(indstate, tuple, TU_All);
 
 		if (should_free)
 			heap_freetuple(tuple);
@@ -301,14 +313,15 @@ void
 CatalogTupleUpdate(Relation heapRel, ItemPointer otid, HeapTuple tup)
 {
 	CatalogIndexState indstate;
+	TU_UpdateIndexes updateIndexes = TU_All;
 
 	CatalogTupleCheckConstraints(heapRel, tup);
 
 	indstate = CatalogOpenIndexes(heapRel);
 
-	simple_heap_update(heapRel, otid, tup);
+	simple_heap_update(heapRel, otid, tup, &updateIndexes);
 
-	CatalogIndexInsert(indstate, tup);
+	CatalogIndexInsert(indstate, tup, updateIndexes);
 	CatalogCloseIndexes(indstate);
 }
 
@@ -324,11 +337,13 @@ void
 CatalogTupleUpdateWithInfo(Relation heapRel, ItemPointer otid, HeapTuple tup,
 						   CatalogIndexState indstate)
 {
+	TU_UpdateIndexes updateIndexes = TU_All;
+
 	CatalogTupleCheckConstraints(heapRel, tup);
 
-	simple_heap_update(heapRel, otid, tup);
+	simple_heap_update(heapRel, otid, tup, &updateIndexes);
 
-	CatalogIndexInsert(indstate, tup);
+	CatalogIndexInsert(indstate, tup, updateIndexes);
 }
 
 /*
diff --git a/src/backend/commands/copyfrom.c b/src/backend/commands/copyfrom.c
index af52faca6d4..564520289a8 100644
--- a/src/backend/commands/copyfrom.c
+++ b/src/backend/commands/copyfrom.c
@@ -435,7 +435,7 @@ CopyMultiInsertBufferFlush(CopyMultiInsertInfo *miinfo,
 				recheckIndexes =
 					ExecInsertIndexTuples(resultRelInfo,
 										  buffer->slots[i], estate, false,
-										  false, NULL, NIL);
+										  false, NULL, NIL, false);
 				ExecARInsertTriggers(estate, resultRelInfo,
 									 slots[i], recheckIndexes,
 									 cstate->transition_capture);
@@ -1254,7 +1254,8 @@ CopyFrom(CopyFromState cstate)
 																   false,
 																   false,
 																   NULL,
-																   NIL);
+																   NIL,
+																   false);
 					}
 
 					/* AFTER ROW INSERT Triggers */
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index 16ec0b114e6..ff48f44c66f 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -184,6 +184,7 @@ CheckIndexCompatible(Oid oldId,
 	Form_pg_am	accessMethodForm;
 	IndexAmRoutine *amRoutine;
 	bool		amcanorder;
+	bool		amsummarizing;
 	int16	   *coloptions;
 	IndexInfo  *indexInfo;
 	int			numberOfAttributes;
@@ -222,6 +223,7 @@ CheckIndexCompatible(Oid oldId,
 	ReleaseSysCache(tuple);
 
 	amcanorder = amRoutine->amcanorder;
+	amsummarizing = amRoutine->amsummarizing;
 
 	/*
 	 * Compute the operator classes, collations, and exclusion operators for
@@ -232,7 +234,8 @@ CheckIndexCompatible(Oid oldId,
 	 * ii_NumIndexKeyAttrs with same value.
 	 */
 	indexInfo = makeIndexInfo(numberOfAttributes, numberOfAttributes,
-							  accessMethodId, NIL, NIL, false, false, false, false);
+							  accessMethodId, NIL, NIL, false, false,
+							  false, false, amsummarizing);
 	typeObjectId = palloc_array(Oid, numberOfAttributes);
 	collationObjectId = palloc_array(Oid, numberOfAttributes);
 	classObjectId = palloc_array(Oid, numberOfAttributes);
@@ -550,6 +553,7 @@ DefineIndex(Oid relationId,
 	Form_pg_am	accessMethodForm;
 	IndexAmRoutine *amRoutine;
 	bool		amcanorder;
+	bool		amissummarizing;
 	amoptions_function amoptions;
 	bool		partitioned;
 	bool		safe_index;
@@ -866,6 +870,7 @@ DefineIndex(Oid relationId,
 
 	amcanorder = amRoutine->amcanorder;
 	amoptions = amRoutine->amoptions;
+	amissummarizing = amRoutine->amsummarizing;
 
 	pfree(amRoutine);
 	ReleaseSysCache(tuple);
@@ -897,7 +902,8 @@ DefineIndex(Oid relationId,
 							  stmt->unique,
 							  stmt->nulls_not_distinct,
 							  !concurrent,
-							  concurrent);
+							  concurrent,
+							  amissummarizing);
 
 	typeObjectId = palloc_array(Oid, numberOfAttributes);
 	collationObjectId = palloc_array(Oid, numberOfAttributes);
diff --git a/src/backend/executor/execIndexing.c b/src/backend/executor/execIndexing.c
index 6e88e72813f..da28e5e40ca 100644
--- a/src/backend/executor/execIndexing.c
+++ b/src/backend/executor/execIndexing.c
@@ -259,15 +259,24 @@ ExecCloseIndices(ResultRelInfo *resultRelInfo)
  *		into all the relations indexing the result relation
  *		when a heap tuple is inserted into the result relation.
  *
- *		When 'update' is true, executor is performing an UPDATE
- *		that could not use an optimization like heapam's HOT (in
- *		more general terms a call to table_tuple_update() took
- *		place and set 'update_indexes' to true).  Receiving this
- *		hint makes us consider if we should pass down the
- *		'indexUnchanged' hint in turn.  That's something that we
- *		figure out for each index_insert() call iff 'update' is
- *		true.  (When 'update' is false we already know not to pass
- *		the hint to any index.)
+ *		When 'update' is true and 'onlySummarizing' is false,
+ *		executor is performing an UPDATE that could not use an
+ *		optimization like heapam's HOT (in more general terms a
+ *		call to table_tuple_update() took place and set
+ *		'update_indexes' to TUUI_All).  Receiving this hint makes
+ *		us consider if we should pass down the 'indexUnchanged'
+ *		hint in turn.  That's something that we figure out for
+ *		each index_insert() call iff 'update' is true.
+ *		(When 'update' is false we already know not to pass the
+ *		hint to any index.)
+ *
+ *		If onlySummarizing is set, an equivalent optimization to
+ *		HOT has been applied and any updated columns are indexed
+ *		only by summarizing indexes (or in more general terms a
+ *		call to table_tuple_update() took place and set
+ *		'update_indexes' to TUUI_Summarizing). We can (and must)
+ *		therefore only update the indexes that have
+ *		'amsummarizing' = true.
  *
  *		Unique and exclusion constraints are enforced at the same
  *		time.  This returns a list of index OIDs for any unique or
@@ -287,7 +296,8 @@ ExecInsertIndexTuples(ResultRelInfo *resultRelInfo,
 					  bool update,
 					  bool noDupErr,
 					  bool *specConflict,
-					  List *arbiterIndexes)
+					  List *arbiterIndexes,
+					  bool onlySummarizing)
 {
 	ItemPointer tupleid = &slot->tts_tid;
 	List	   *result = NIL;
@@ -343,6 +353,13 @@ ExecInsertIndexTuples(ResultRelInfo *resultRelInfo,
 		if (!indexInfo->ii_ReadyForInserts)
 			continue;
 
+		/*
+		 * Skip processing of non-summarizing indexes if we only
+		 * update summarizing indexes
+		 */
+		if (onlySummarizing && !indexInfo->ii_Summarizing)
+			continue;
+
 		/* Check for partial index */
 		if (indexInfo->ii_Predicate != NIL)
 		{
diff --git a/src/backend/executor/execReplication.c b/src/backend/executor/execReplication.c
index c484f5c3019..4c01ef63cb1 100644
--- a/src/backend/executor/execReplication.c
+++ b/src/backend/executor/execReplication.c
@@ -445,7 +445,7 @@ ExecSimpleRelationInsert(ResultRelInfo *resultRelInfo,
 		if (resultRelInfo->ri_NumIndices > 0)
 			recheckIndexes = ExecInsertIndexTuples(resultRelInfo,
 												   slot, estate, false, false,
-												   NULL, NIL);
+												   NULL, NIL, false);
 
 		/* AFTER ROW INSERT Triggers */
 		ExecARInsertTriggers(estate, resultRelInfo, slot,
@@ -493,7 +493,7 @@ ExecSimpleRelationUpdate(ResultRelInfo *resultRelInfo,
 	if (!skip_tuple)
 	{
 		List	   *recheckIndexes = NIL;
-		bool		update_indexes;
+		TU_UpdateIndexes update_indexes;
 
 		/* Compute stored generated columns */
 		if (rel->rd_att->constr &&
@@ -510,10 +510,11 @@ ExecSimpleRelationUpdate(ResultRelInfo *resultRelInfo,
 		simple_table_tuple_update(rel, tid, slot, estate->es_snapshot,
 								  &update_indexes);
 
-		if (resultRelInfo->ri_NumIndices > 0 && update_indexes)
+		if (resultRelInfo->ri_NumIndices > 0 && update_indexes != TU_None)
 			recheckIndexes = ExecInsertIndexTuples(resultRelInfo,
 												   slot, estate, true, false,
-												   NULL, NIL);
+												   NULL, NIL,
+												   update_indexes == TU_Summarizing);
 
 		/* AFTER ROW UPDATE Triggers */
 		ExecARUpdateTriggers(estate, resultRelInfo,
diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index a94d7f86e54..099ccda95ac 100644
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -125,8 +125,8 @@ typedef struct ModifyTableContext
 typedef struct UpdateContext
 {
 	bool		updated;		/* did UPDATE actually occur? */
-	bool		updateIndexes;	/* index update required? */
 	bool		crossPartUpdate;	/* was it a cross-partition update? */
+	TU_UpdateIndexes updateIndexes;	/* Which index updates are required? */
 
 	/*
 	 * Lock mode to acquire on the latest tuple version before performing
@@ -1106,7 +1106,8 @@ ExecInsert(ModifyTableContext *context,
 			recheckIndexes = ExecInsertIndexTuples(resultRelInfo,
 												   slot, estate, false, true,
 												   &specConflict,
-												   arbiterIndexes);
+												   arbiterIndexes,
+												   false);
 
 			/* adjust the tuple's state accordingly */
 			table_tuple_complete_speculative(resultRelationDesc, slot,
@@ -1145,7 +1146,8 @@ ExecInsert(ModifyTableContext *context,
 			if (resultRelInfo->ri_NumIndices > 0)
 				recheckIndexes = ExecInsertIndexTuples(resultRelInfo,
 													   slot, estate, false,
-													   false, NULL, NIL);
+													   false, NULL, NIL,
+													   false);
 		}
 	}
 
@@ -2108,11 +2110,12 @@ ExecUpdateEpilogue(ModifyTableContext *context, UpdateContext *updateCxt,
 	ModifyTableState *mtstate = context->mtstate;
 
 	/* insert index entries for tuple if necessary */
-	if (resultRelInfo->ri_NumIndices > 0 && updateCxt->updateIndexes)
+	if (resultRelInfo->ri_NumIndices > 0 && updateCxt->updateIndexes != TU_None)
 		recheckIndexes = ExecInsertIndexTuples(resultRelInfo,
 											   slot, context->estate,
 											   true, false,
-											   NULL, NIL);
+											   NULL, NIL,
+											   updateCxt->updateIndexes == TU_Summarizing);
 
 	/* AFTER ROW UPDATE Triggers */
 	ExecARUpdateTriggers(context->estate, resultRelInfo,
diff --git a/src/backend/nodes/makefuncs.c b/src/backend/nodes/makefuncs.c
index fe67baf1420..f23f8b73492 100644
--- a/src/backend/nodes/makefuncs.c
+++ b/src/backend/nodes/makefuncs.c
@@ -743,7 +743,8 @@ make_ands_implicit(Expr *clause)
  */
 IndexInfo *
 makeIndexInfo(int numattrs, int numkeyattrs, Oid amoid, List *expressions,
-			  List *predicates, bool unique, bool nulls_not_distinct, bool isready, bool concurrent)
+			  List *predicates, bool unique, bool nulls_not_distinct,
+			  bool isready, bool concurrent, bool summarizing)
 {
 	IndexInfo  *n = makeNode(IndexInfo);
 
@@ -757,6 +758,10 @@ makeIndexInfo(int numattrs, int numkeyattrs, Oid amoid, List *expressions,
 	n->ii_CheckedUnchanged = false;
 	n->ii_IndexUnchanged = false;
 	n->ii_Concurrent = concurrent;
+	n->ii_Summarizing = summarizing;
+
+	/* summarizing indexes cannot contain non-key attributes */
+	Assert(!summarizing || numkeyattrs == numattrs);
 
 	/* expressions */
 	n->ii_Expressions = expressions;
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index 13f79873733..092c5ed8c7f 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -2440,10 +2440,11 @@ RelationDestroyRelation(Relation relation, bool remember_tupdesc)
 	list_free_deep(relation->rd_fkeylist);
 	list_free(relation->rd_indexlist);
 	list_free(relation->rd_statlist);
-	bms_free(relation->rd_indexattr);
 	bms_free(relation->rd_keyattr);
 	bms_free(relation->rd_pkattr);
 	bms_free(relation->rd_idattr);
+	bms_free(relation->rd_hotblockingattr);
+	bms_free(relation->rd_summarizedattr);
 	if (relation->rd_pubdesc)
 		pfree(relation->rd_pubdesc);
 	if (relation->rd_options)
@@ -5167,10 +5168,11 @@ RelationGetIndexPredicate(Relation relation)
 Bitmapset *
 RelationGetIndexAttrBitmap(Relation relation, IndexAttrBitmapKind attrKind)
 {
-	Bitmapset  *indexattrs;		/* indexed columns */
 	Bitmapset  *uindexattrs;	/* columns in unique indexes */
 	Bitmapset  *pkindexattrs;	/* columns in the primary index */
 	Bitmapset  *idindexattrs;	/* columns in the replica identity */
+	Bitmapset  *hotblockingattrs;   /* columns with HOT blocking indexes */
+	Bitmapset  *summarizedattrs;   /* columns with summarizing indexes */
 	List	   *indexoidlist;
 	List	   *newindexoidlist;
 	Oid			relpkindex;
@@ -5179,18 +5181,20 @@ RelationGetIndexAttrBitmap(Relation relation, IndexAttrBitmapKind attrKind)
 	MemoryContext oldcxt;
 
 	/* Quick exit if we already computed the result. */
-	if (relation->rd_indexattr != NULL)
+	if (relation->rd_attrsvalid)
 	{
 		switch (attrKind)
 		{
-			case INDEX_ATTR_BITMAP_ALL:
-				return bms_copy(relation->rd_indexattr);
 			case INDEX_ATTR_BITMAP_KEY:
 				return bms_copy(relation->rd_keyattr);
 			case INDEX_ATTR_BITMAP_PRIMARY_KEY:
 				return bms_copy(relation->rd_pkattr);
 			case INDEX_ATTR_BITMAP_IDENTITY_KEY:
 				return bms_copy(relation->rd_idattr);
+			case INDEX_ATTR_BITMAP_HOT_BLOCKING:
+				return bms_copy(relation->rd_hotblockingattr);
+			case INDEX_ATTR_BITMAP_SUMMARIZED:
+				return bms_copy(relation->rd_summarizedattr);
 			default:
 				elog(ERROR, "unknown attrKind %u", attrKind);
 		}
@@ -5230,10 +5234,11 @@ restart:
 	 * CONCURRENTLY is far enough along that we should ignore the index, it
 	 * won't be returned at all by RelationGetIndexList.
 	 */
-	indexattrs = NULL;
 	uindexattrs = NULL;
 	pkindexattrs = NULL;
 	idindexattrs = NULL;
+	hotblockingattrs = NULL;
+	summarizedattrs = NULL;
 	foreach(l, indexoidlist)
 	{
 		Oid			indexOid = lfirst_oid(l);
@@ -5291,15 +5296,25 @@ restart:
 			/*
 			 * Since we have covering indexes with non-key columns, we must
 			 * handle them accurately here. non-key columns must be added into
-			 * indexattrs, since they are in index, and HOT-update shouldn't
-			 * miss them. Obviously, non-key columns couldn't be referenced by
+			 * hotblockingattrs, since they are in index, and HOT-update
+			 * shouldn't miss them.
+			 * 
+			 * Summarizing indexes do not block HOT, but do need to be updated
+			 * when the column value changes, thus require a separate
+			 * attribute bitmapset.
+			 *
+			 * Obviously, non-key columns couldn't be referenced by
 			 * foreign key or identity key. Hence we do not include them into
 			 * uindexattrs, pkindexattrs and idindexattrs bitmaps.
 			 */
 			if (attrnum != 0)
 			{
-				indexattrs = bms_add_member(indexattrs,
-											attrnum - FirstLowInvalidHeapAttributeNumber);
+				if (indexDesc->rd_indam->amsummarizing)
+					summarizedattrs = bms_add_member(summarizedattrs,
+													 attrnum - FirstLowInvalidHeapAttributeNumber);
+				else
+					hotblockingattrs = bms_add_member(hotblockingattrs,
+													  attrnum - FirstLowInvalidHeapAttributeNumber);
 
 				if (isKey && i < indexDesc->rd_index->indnkeyatts)
 					uindexattrs = bms_add_member(uindexattrs,
@@ -5316,10 +5331,18 @@ restart:
 		}
 
 		/* Collect all attributes used in expressions, too */
-		pull_varattnos(indexExpressions, 1, &indexattrs);
+		if (indexDesc->rd_indam->amsummarizing)
+			pull_varattnos(indexExpressions, 1, &summarizedattrs);
+		else
+			pull_varattnos(indexExpressions, 1, &hotblockingattrs);
 
-		/* Collect all attributes in the index predicate, too */
-		pull_varattnos(indexPredicate, 1, &indexattrs);
+		/*
+		 * Collect all attributes in the index predicate, too.
+		 */
+		if (indexDesc->rd_indam->amsummarizing)
+			pull_varattnos(indexPredicate, 1, &summarizedattrs);
+		else
+			pull_varattnos(indexPredicate, 1, &hotblockingattrs);
 
 		index_close(indexDesc, AccessShareLock);
 	}
@@ -5347,24 +5370,28 @@ restart:
 		bms_free(uindexattrs);
 		bms_free(pkindexattrs);
 		bms_free(idindexattrs);
-		bms_free(indexattrs);
+		bms_free(hotblockingattrs);
+		bms_free(summarizedattrs);
 
 		goto restart;
 	}
 
 	/* Don't leak the old values of these bitmaps, if any */
-	bms_free(relation->rd_indexattr);
-	relation->rd_indexattr = NULL;
+	relation->rd_attrsvalid = false;
 	bms_free(relation->rd_keyattr);
 	relation->rd_keyattr = NULL;
 	bms_free(relation->rd_pkattr);
 	relation->rd_pkattr = NULL;
 	bms_free(relation->rd_idattr);
 	relation->rd_idattr = NULL;
+	bms_free(relation->rd_hotblockingattr);
+	relation->rd_hotblockingattr = NULL;
+	bms_free(relation->rd_summarizedattr);
+	relation->rd_summarizedattr = NULL;
 
 	/*
 	 * Now save copies of the bitmaps in the relcache entry.  We intentionally
-	 * set rd_indexattr last, because that's the one that signals validity of
+	 * set rd_attrsvalid last, because that's the one that signals validity of
 	 * the values; if we run out of memory before making that copy, we won't
 	 * leave the relcache entry looking like the other ones are valid but
 	 * empty.
@@ -5373,20 +5400,24 @@ restart:
 	relation->rd_keyattr = bms_copy(uindexattrs);
 	relation->rd_pkattr = bms_copy(pkindexattrs);
 	relation->rd_idattr = bms_copy(idindexattrs);
-	relation->rd_indexattr = bms_copy(indexattrs);
+	relation->rd_hotblockingattr = bms_copy(hotblockingattrs);
+	relation->rd_summarizedattr = bms_copy(summarizedattrs);
+	relation->rd_attrsvalid = true;
 	MemoryContextSwitchTo(oldcxt);
 
 	/* We return our original working copy for caller to play with */
 	switch (attrKind)
 	{
-		case INDEX_ATTR_BITMAP_ALL:
-			return indexattrs;
 		case INDEX_ATTR_BITMAP_KEY:
 			return uindexattrs;
 		case INDEX_ATTR_BITMAP_PRIMARY_KEY:
 			return pkindexattrs;
 		case INDEX_ATTR_BITMAP_IDENTITY_KEY:
 			return idindexattrs;
+		case INDEX_ATTR_BITMAP_HOT_BLOCKING:
+			return hotblockingattrs;
+		case INDEX_ATTR_BITMAP_SUMMARIZED:
+			return summarizedattrs;
 		default:
 			elog(ERROR, "unknown attrKind %u", attrKind);
 			return NULL;
@@ -6307,7 +6338,7 @@ load_relcache_init_file(bool shared)
 		rel->rd_indexlist = NIL;
 		rel->rd_pkindex = InvalidOid;
 		rel->rd_replidindex = InvalidOid;
-		rel->rd_indexattr = NULL;
+		rel->rd_attrsvalid = false;
 		rel->rd_keyattr = NULL;
 		rel->rd_pkattr = NULL;
 		rel->rd_idattr = NULL;
diff --git a/src/include/access/amapi.h b/src/include/access/amapi.h
index 4f1f67b4d03..281039ef673 100644
--- a/src/include/access/amapi.h
+++ b/src/include/access/amapi.h
@@ -244,6 +244,8 @@ typedef struct IndexAmRoutine
 	bool		amcaninclude;
 	/* does AM use maintenance_work_mem? */
 	bool		amusemaintenanceworkmem;
+	/* does AM store tuple information only at block granularity? */
+	bool        amsummarizing;
 	/* OR of parallel vacuum flags.  See vacuum.h for flags. */
 	uint8		amparallelvacuumoptions;
 	/* type of data stored in index, or InvalidOid if variable */
diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h
index 8d74d1b7e30..faf50265191 100644
--- a/src/include/access/heapam.h
+++ b/src/include/access/heapam.h
@@ -249,7 +249,8 @@ extern void heap_abort_speculative(Relation relation, ItemPointer tid);
 extern TM_Result heap_update(Relation relation, ItemPointer otid,
 							 HeapTuple newtup,
 							 CommandId cid, Snapshot crosscheck, bool wait,
-							 struct TM_FailureData *tmfd, LockTupleMode *lockmode);
+							 struct TM_FailureData *tmfd, LockTupleMode *lockmode,
+							 TU_UpdateIndexes *update_indexes);
 extern TM_Result heap_lock_tuple(Relation relation, HeapTuple tuple,
 								 CommandId cid, LockTupleMode mode, LockWaitPolicy wait_policy,
 								 bool follow_updates,
@@ -275,7 +276,7 @@ extern bool heap_tuple_needs_eventual_freeze(HeapTupleHeader tuple);
 extern void simple_heap_insert(Relation relation, HeapTuple tup);
 extern void simple_heap_delete(Relation relation, ItemPointer tid);
 extern void simple_heap_update(Relation relation, ItemPointer otid,
-							   HeapTuple tup);
+							   HeapTuple tup, TU_UpdateIndexes *update_indexes);
 
 extern TransactionId heap_index_delete_tuples(Relation rel,
 											  TM_IndexDeleteOp *delstate);
diff --git a/src/include/access/tableam.h b/src/include/access/tableam.h
index 652e96f1b0b..f31d7693ecd 100644
--- a/src/include/access/tableam.h
+++ b/src/include/access/tableam.h
@@ -102,6 +102,19 @@ typedef enum TM_Result
 	TM_WouldBlock
 } TM_Result;
 
+/*
+ * Result codes for table_update(..., update_indexes*..).
+ * Used to determine which indexes to update.
+ */
+typedef enum TU_UpdateIndexes {
+	/* No indexed columns were updated (incl. TID addressing of tuple) */
+	TU_None = 0,
+	/* A non-summarizing indexed column was updated, or the TID has changed */
+	TU_All = 1,
+	/* Only summarized columns were updated, TID is unchanged */
+	TU_Summarizing = 2
+} TU_UpdateIndexes;
+
 /*
  * When table_tuple_update, table_tuple_delete, or table_tuple_lock fail
  * because the target tuple is already outdated, they fill in this struct to
@@ -526,7 +539,7 @@ typedef struct TableAmRoutine
 								 bool wait,
 								 TM_FailureData *tmfd,
 								 LockTupleMode *lockmode,
-								 bool *update_indexes);
+								 TU_UpdateIndexes *update_indexes);
 
 	/* see table_tuple_lock() for reference about parameters */
 	TM_Result	(*tuple_lock) (Relation rel,
@@ -1514,7 +1527,7 @@ static inline TM_Result
 table_tuple_update(Relation rel, ItemPointer otid, TupleTableSlot *slot,
 				   CommandId cid, Snapshot snapshot, Snapshot crosscheck,
 				   bool wait, TM_FailureData *tmfd, LockTupleMode *lockmode,
-				   bool *update_indexes)
+				   TU_UpdateIndexes *update_indexes)
 {
 	return rel->rd_tableam->tuple_update(rel, otid, slot,
 										 cid, snapshot, crosscheck,
@@ -2038,7 +2051,7 @@ extern void simple_table_tuple_delete(Relation rel, ItemPointer tid,
 									  Snapshot snapshot);
 extern void simple_table_tuple_update(Relation rel, ItemPointer otid,
 									  TupleTableSlot *slot, Snapshot snapshot,
-									  bool *update_indexes);
+									  TU_UpdateIndexes *update_indexes);
 
 
 /* ----------------------------------------------------------------------------
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h
index e7e25c057ef..551c5d7ae0c 100644
--- a/src/include/executor/executor.h
+++ b/src/include/executor/executor.h
@@ -620,7 +620,8 @@ extern List *ExecInsertIndexTuples(ResultRelInfo *resultRelInfo,
 								   TupleTableSlot *slot, EState *estate,
 								   bool update,
 								   bool noDupErr,
-								   bool *specConflict, List *arbiterIndexes);
+								   bool *specConflict, List *arbiterIndexes,
+								   bool onlySummarizing);
 extern bool ExecCheckIndexConstraints(ResultRelInfo *resultRelInfo,
 									  TupleTableSlot *slot,
 									  EState *estate, ItemPointer conflictTid,
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 20f4c8b35f3..3f1b8818a1f 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -161,6 +161,7 @@ typedef struct ExprState
  *		IndexUnchanged		aminsert hint, cached for retail inserts
  *		Concurrent			are we doing a concurrent index build?
  *		BrokenHotChain		did we detect any broken HOT chains?
+ *		Summarizing			is it summarizing?
  *		ParallelWorkers		# of workers requested (excludes leader)
  *		Am					Oid of index AM
  *		AmCache				private cache area for index AM
@@ -194,6 +195,7 @@ typedef struct IndexInfo
 	bool		ii_IndexUnchanged;
 	bool		ii_Concurrent;
 	bool		ii_BrokenHotChain;
+	bool		ii_Summarizing;
 	int			ii_ParallelWorkers;
 	Oid			ii_Am;
 	void	   *ii_AmCache;
diff --git a/src/include/nodes/makefuncs.h b/src/include/nodes/makefuncs.h
index 80f1d5336bb..64651c9b00b 100644
--- a/src/include/nodes/makefuncs.h
+++ b/src/include/nodes/makefuncs.h
@@ -96,7 +96,9 @@ extern List *make_ands_implicit(Expr *clause);
 
 extern IndexInfo *makeIndexInfo(int numattrs, int numkeyattrs, Oid amoid,
 								List *expressions, List *predicates,
-								bool unique, bool nulls_not_distinct, bool isready, bool concurrent);
+								bool unique, bool nulls_not_distinct,
+								bool isready, bool concurrent,
+								bool summarizing);
 
 extern DefElem *makeDefElem(char *name, Node *arg, int location);
 extern DefElem *makeDefElemExtended(char *nameSpace, char *name, Node *arg,
diff --git a/src/include/utils/rel.h b/src/include/utils/rel.h
index 67f994cb3e2..c0ddddb2f0d 100644
--- a/src/include/utils/rel.h
+++ b/src/include/utils/rel.h
@@ -156,10 +156,12 @@ typedef struct RelationData
 	List	   *rd_statlist;	/* list of OIDs of extended stats */
 
 	/* data managed by RelationGetIndexAttrBitmap: */
-	Bitmapset  *rd_indexattr;	/* identifies columns used in indexes */
+	bool		rd_attrsvalid;	/* are bitmaps of attrs valid? */
 	Bitmapset  *rd_keyattr;		/* cols that can be ref'd by foreign keys */
 	Bitmapset  *rd_pkattr;		/* cols included in primary key */
 	Bitmapset  *rd_idattr;		/* included in replica identity index */
+	Bitmapset  *rd_hotblockingattr;	/* cols blocking HOT update */
+	Bitmapset  *rd_summarizedattr;	/* cols indexed by summarizing indexes */
 
 	PublicationDesc *rd_pubdesc;	/* publication descriptor, or NULL */
 
diff --git a/src/include/utils/relcache.h b/src/include/utils/relcache.h
index 88460f21c56..beeb28b83cb 100644
--- a/src/include/utils/relcache.h
+++ b/src/include/utils/relcache.h
@@ -56,10 +56,11 @@ extern bytea **RelationGetIndexAttOptions(Relation relation, bool copy);
 
 typedef enum IndexAttrBitmapKind
 {
-	INDEX_ATTR_BITMAP_ALL,
 	INDEX_ATTR_BITMAP_KEY,
 	INDEX_ATTR_BITMAP_PRIMARY_KEY,
-	INDEX_ATTR_BITMAP_IDENTITY_KEY
+	INDEX_ATTR_BITMAP_IDENTITY_KEY,
+	INDEX_ATTR_BITMAP_HOT_BLOCKING,
+	INDEX_ATTR_BITMAP_SUMMARIZED
 } IndexAttrBitmapKind;
 
 extern Bitmapset *RelationGetIndexAttrBitmap(Relation relation,
diff --git a/src/test/modules/dummy_index_am/dummy_index_am.c b/src/test/modules/dummy_index_am/dummy_index_am.c
index dfb1ebb846a..c14e0abe0c6 100644
--- a/src/test/modules/dummy_index_am/dummy_index_am.c
+++ b/src/test/modules/dummy_index_am/dummy_index_am.c
@@ -296,6 +296,7 @@ dihandler(PG_FUNCTION_ARGS)
 	amroutine->amcanparallel = false;
 	amroutine->amcaninclude = false;
 	amroutine->amusemaintenanceworkmem = false;
+	amroutine->amsummarizing = false;
 	amroutine->amparallelvacuumoptions = VACUUM_OPTION_NO_PARALLEL;
 	amroutine->amkeytype = InvalidOid;
 
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 937b2101b33..728c474cfa3 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -1354,4 +1354,114 @@ SELECT :io_stats_post_reset < :io_stats_pre_reset;
  t
 (1 row)
 
+-- test BRIN index doesn't block HOT update
+CREATE TABLE brin_hot (
+  id  integer PRIMARY KEY,
+  val integer NOT NULL
+) WITH (autovacuum_enabled = off, fillfactor = 70);
+INSERT INTO brin_hot SELECT *, 0 FROM generate_series(1, 235);
+CREATE INDEX val_brin ON brin_hot using brin(val);
+CREATE FUNCTION wait_for_hot_stats() RETURNS void AS $$
+DECLARE
+  start_time timestamptz := clock_timestamp();
+  updated bool;
+BEGIN
+  -- we don't want to wait forever; loop will exit after 30 seconds
+  FOR i IN 1 .. 300 LOOP
+    SELECT (pg_stat_get_tuples_hot_updated('brin_hot'::regclass::oid) > 0) INTO updated;
+    EXIT WHEN updated;
+
+    -- wait a little
+    PERFORM pg_sleep_for('100 milliseconds');
+    -- reset stats snapshot so we can test again
+    PERFORM pg_stat_clear_snapshot();
+  END LOOP;
+  -- report time waited in postmaster log (where it won't change test output)
+  RAISE log 'wait_for_hot_stats delayed % seconds',
+    EXTRACT(epoch FROM clock_timestamp() - start_time);
+END
+$$ LANGUAGE plpgsql;
+UPDATE brin_hot SET val = -3 WHERE id = 42;
+-- We can't just call wait_for_hot_stats() at this point, because we only
+-- transmit stats when the session goes idle, and we probably didn't
+-- transmit the last couple of counts yet thanks to the rate-limiting logic
+-- in pgstat_report_stat().  But instead of waiting for the rate limiter's
+-- timeout to elapse, let's just start a new session.  The old one will
+-- then send its stats before dying.
+\c -
+SELECT wait_for_hot_stats();
+ wait_for_hot_stats 
+--------------------
+ 
+(1 row)
+
+SELECT pg_stat_get_tuples_hot_updated('brin_hot'::regclass::oid);
+ pg_stat_get_tuples_hot_updated 
+--------------------------------
+                              1
+(1 row)
+
+DROP TABLE brin_hot;
+DROP FUNCTION wait_for_hot_stats();
+-- Test handling of index predicates - updating attributes in precicates
+-- should block HOT even for BRIN. We update a row that was not indexed
+-- due to the index predicate, and becomes indexable.
+CREATE TABLE brin_hot_2 (a int, b int);
+INSERT INTO brin_hot_2 VALUES (1, 100);
+CREATE INDEX ON brin_hot_2 USING brin (b) WHERE a = 2;
+UPDATE brin_hot_2 SET a = 2;
+EXPLAIN (COSTS OFF) SELECT * FROM brin_hot_2 WHERE a = 2 AND b = 100;
+            QUERY PLAN             
+-----------------------------------
+ Seq Scan on brin_hot_2
+   Filter: ((a = 2) AND (b = 100))
+(2 rows)
+
+SELECT COUNT(*) FROM brin_hot_2 WHERE a = 2 AND b = 100;
+ count 
+-------
+     1
+(1 row)
+
+SET enable_seqscan = off;
+EXPLAIN (COSTS OFF) SELECT * FROM brin_hot_2 WHERE a = 2 AND b = 100;
+                 QUERY PLAN                  
+---------------------------------------------
+ Bitmap Heap Scan on brin_hot_2
+   Recheck Cond: ((b = 100) AND (a = 2))
+   ->  Bitmap Index Scan on brin_hot_2_b_idx
+         Index Cond: (b = 100)
+(4 rows)
+
+SELECT COUNT(*) FROM brin_hot_2 WHERE a = 2 AND b = 100;
+ count 
+-------
+     1
+(1 row)
+
+DROP TABLE brin_hot_2;
+-- Test that updates to indexed columns are still propagated to the
+-- BRIN column.
+-- https://postgr.es/m/05ebcb44-f383-86e3-4f31-0a97a55634cf@enterprisedb.com
+CREATE TABLE brin_hot_3 (a int, filler text) WITH (fillfactor = 10);
+INSERT INTO brin_hot_3 SELECT 1, repeat(' ', 500) FROM generate_series(1, 20);
+CREATE INDEX ON brin_hot_3 USING brin (a) WITH (pages_per_range = 1);
+UPDATE brin_hot_3 SET a = 2;
+EXPLAIN (COSTS OFF) SELECT * FROM brin_hot_3 WHERE a = 2;
+                 QUERY PLAN                  
+---------------------------------------------
+ Bitmap Heap Scan on brin_hot_3
+   Recheck Cond: (a = 2)
+   ->  Bitmap Index Scan on brin_hot_3_a_idx
+         Index Cond: (a = 2)
+(4 rows)
+
+SELECT COUNT(*) FROM brin_hot_3 WHERE a = 2;
+ count 
+-------
+    20
+(1 row)
+
+DROP TABLE brin_hot_3;
+SET enable_seqscan = on;
 -- End of Stats Test
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 74e592aa8af..e113f6906c9 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -535,7 +535,6 @@ SET enable_seqscan TO on;
 SELECT pg_stat_get_replication_slot(NULL);
 SELECT pg_stat_get_subscription_stats(NULL);
 
-
 -- Test that the following operations are tracked in pg_stat_io:
 -- - reads of target blocks into shared buffers
 -- - writes of shared buffers to permanent storage
@@ -678,4 +677,85 @@ SELECT sum(evictions) + sum(reuses) + sum(extends) + sum(fsyncs) + sum(reads) +
   FROM pg_stat_io \gset
 SELECT :io_stats_post_reset < :io_stats_pre_reset;
 
+
+-- test BRIN index doesn't block HOT update
+CREATE TABLE brin_hot (
+  id  integer PRIMARY KEY,
+  val integer NOT NULL
+) WITH (autovacuum_enabled = off, fillfactor = 70);
+
+INSERT INTO brin_hot SELECT *, 0 FROM generate_series(1, 235);
+CREATE INDEX val_brin ON brin_hot using brin(val);
+
+CREATE FUNCTION wait_for_hot_stats() RETURNS void AS $$
+DECLARE
+  start_time timestamptz := clock_timestamp();
+  updated bool;
+BEGIN
+  -- we don't want to wait forever; loop will exit after 30 seconds
+  FOR i IN 1 .. 300 LOOP
+    SELECT (pg_stat_get_tuples_hot_updated('brin_hot'::regclass::oid) > 0) INTO updated;
+    EXIT WHEN updated;
+
+    -- wait a little
+    PERFORM pg_sleep_for('100 milliseconds');
+    -- reset stats snapshot so we can test again
+    PERFORM pg_stat_clear_snapshot();
+  END LOOP;
+  -- report time waited in postmaster log (where it won't change test output)
+  RAISE log 'wait_for_hot_stats delayed % seconds',
+    EXTRACT(epoch FROM clock_timestamp() - start_time);
+END
+$$ LANGUAGE plpgsql;
+
+UPDATE brin_hot SET val = -3 WHERE id = 42;
+
+-- We can't just call wait_for_hot_stats() at this point, because we only
+-- transmit stats when the session goes idle, and we probably didn't
+-- transmit the last couple of counts yet thanks to the rate-limiting logic
+-- in pgstat_report_stat().  But instead of waiting for the rate limiter's
+-- timeout to elapse, let's just start a new session.  The old one will
+-- then send its stats before dying.
+\c -
+
+SELECT wait_for_hot_stats();
+SELECT pg_stat_get_tuples_hot_updated('brin_hot'::regclass::oid);
+
+DROP TABLE brin_hot;
+DROP FUNCTION wait_for_hot_stats();
+
+-- Test handling of index predicates - updating attributes in precicates
+-- should block HOT even for BRIN. We update a row that was not indexed
+-- due to the index predicate, and becomes indexable.
+CREATE TABLE brin_hot_2 (a int, b int);
+INSERT INTO brin_hot_2 VALUES (1, 100);
+CREATE INDEX ON brin_hot_2 USING brin (b) WHERE a = 2;
+
+UPDATE brin_hot_2 SET a = 2;
+
+EXPLAIN (COSTS OFF) SELECT * FROM brin_hot_2 WHERE a = 2 AND b = 100;
+SELECT COUNT(*) FROM brin_hot_2 WHERE a = 2 AND b = 100;
+
+SET enable_seqscan = off;
+
+EXPLAIN (COSTS OFF) SELECT * FROM brin_hot_2 WHERE a = 2 AND b = 100;
+SELECT COUNT(*) FROM brin_hot_2 WHERE a = 2 AND b = 100;
+
+DROP TABLE brin_hot_2;
+
+-- Test that updates to indexed columns are still propagated to the
+-- BRIN column.
+-- https://postgr.es/m/05ebcb44-f383-86e3-4f31-0a97a55634cf@enterprisedb.com
+CREATE TABLE brin_hot_3 (a int, filler text) WITH (fillfactor = 10);
+INSERT INTO brin_hot_3 SELECT 1, repeat(' ', 500) FROM generate_series(1, 20);
+CREATE INDEX ON brin_hot_3 USING brin (a) WITH (pages_per_range = 1);
+UPDATE brin_hot_3 SET a = 2;
+
+EXPLAIN (COSTS OFF) SELECT * FROM brin_hot_3 WHERE a = 2;
+SELECT COUNT(*) FROM brin_hot_3 WHERE a = 2;
+
+DROP TABLE brin_hot_3;
+
+SET enable_seqscan = on;
+
 -- End of Stats Test
-- 
2.39.1

