v3-0003-cleanup-and-simplification.patch

From f278bd14ca6fcd27b02ebb14feed797d0da721ad Mon Sep 17 00:00:00 2001
From: Tomas Vondra <tomas@vondra.me>
Date: Tue, 17 Mar 2026 22:06:46 +0100
Subject: [PATCH v3 3/6] cleanup and simplification

- Reduce code duplication in explain.c by introducing a couple helper
  methods for repeated blocks - ACCUMULATE_TABLE_STATS() and
  show_io_info().

- Replace ReadStreamInstrumentation with generic IOStats.

- new read_stream_update_stats_stall() wrapper

- enable EXPLAIN (IO) by default, just like BUFFERS

- fix the explain group to have matching objtype/label

- don't update prefetch stats after stream ended

fixup: track prefetch distance
---
 doc/src/sgml/ref/explain.sgml                 |   2 +-
 src/backend/access/heap/heapam.c              |   2 +-
 src/backend/commands/explain.c                | 242 +++++++-----------
 src/backend/commands/explain_state.c          |   5 +
 src/backend/executor/nodeBitmapHeapscan.c     |  11 +-
 src/backend/executor/nodeSeqscan.c            |  11 +-
 src/backend/storage/aio/read_stream.c         |  26 +-
 src/include/access/relscan.h                  |  14 +
 src/include/executor/instrument_node.h        |   8 +-
 src/include/storage/read_stream.h             |   4 +-
 src/test/regress/expected/explain.out         |  39 ++-
 .../regress/expected/incremental_sort.out     |   4 +-
 src/test/regress/expected/memoize.out         |   2 +-
 src/test/regress/expected/merge.out           |   2 +-
 src/test/regress/expected/partition_prune.out |  75 ++++--
 src/test/regress/expected/select_parallel.out |   6 +-
 src/test/regress/expected/subselect.out       |   2 +-
 src/test/regress/sql/explain.sql              |  24 +-
 src/test/regress/sql/incremental_sort.sql     |   4 +-
 src/test/regress/sql/memoize.sql              |   2 +-
 src/test/regress/sql/merge.sql                |   2 +-
 src/test/regress/sql/partition_prune.sql      |   2 +-
 src/test/regress/sql/select_parallel.sql      |   6 +-
 src/test/regress/sql/subselect.sql            |   2 +-
 24 files changed, 252 insertions(+), 245 deletions(-)

diff --git a/doc/src/sgml/ref/explain.sgml b/doc/src/sgml/ref/explain.sgml
index 9da16c77d73..83f27badfc8 100644
--- a/doc/src/sgml/ref/explain.sgml
+++ b/doc/src/sgml/ref/explain.sgml
@@ -302,7 +302,7 @@ ROLLBACK;
      <para>
       Include information on I/O performed by each node.
       This parameter may only be used when <literal>ANALYZE</literal> is also
-      enabled.  It defaults to <literal>FALSE</literal>.
+      enabled.  It defaults to <literal>TRUE</literal>.
      </para>
     </listitem>
    </varlistentry>
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index b13f843cfad..323badd27f1 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -1426,7 +1426,7 @@ TableScanStats
 heap_scan_stats(TableScanDesc sscan)
 {
 	HeapScanDesc scan = (HeapScanDesc) sscan;
-	ReadStreamInstrumentation stats;
+	IOStats stats;
 	TableScanStats res;
 
 	if (!scan->rs_read_stream)
diff --git a/src/backend/commands/explain.c b/src/backend/commands/explain.c
index ad86fb752ca..7a4009ae74f 100644
--- a/src/backend/commands/explain.c
+++ b/src/backend/commands/explain.c
@@ -141,11 +141,11 @@ static void show_hashagg_info(AggState *aggstate, ExplainState *es);
 static void show_indexsearches_info(PlanState *planstate, ExplainState *es);
 static void show_tidbitmap_info(BitmapHeapScanState *planstate,
 								ExplainState *es);
-static void show_scan_io_info(ScanState *planstate,
-							  ExplainState *es);
-static void show_worker_io_info(PlanState *planstate,
-								ExplainState *es,
-								int worker);
+static void show_scan_io_usage(ScanState *planstate,
+							   ExplainState *es);
+static void show_io_usage(PlanState *planstate,
+						  ExplainState *es,
+						  int worker);
 static void show_instrumentation_count(const char *qlabel, int which,
 									   PlanState *planstate, ExplainState *es);
 static void show_foreignscan_info(ForeignScanState *fsstate, ExplainState *es);
@@ -2016,7 +2016,7 @@ ExplainNode(PlanState *planstate, List *ancestors,
 				show_instrumentation_count("Rows Removed by Filter", 1,
 										   planstate, es);
 			show_tidbitmap_info((BitmapHeapScanState *) planstate, es);
-			show_scan_io_info((ScanState *) planstate, es);
+			show_scan_io_usage((ScanState *) planstate, es);
 			break;
 		case T_SampleScan:
 			show_tablesample(((SampleScan *) plan)->tablesample,
@@ -2035,7 +2035,7 @@ ExplainNode(PlanState *planstate, List *ancestors,
 										   planstate, es);
 			if (IsA(plan, CteScan))
 				show_ctescan_info(castNode(CteScanState, planstate), es);
-			show_scan_io_info((ScanState *) planstate, es);
+			show_scan_io_usage((ScanState *) planstate, es);
 			break;
 		case T_Gather:
 			{
@@ -2324,9 +2324,8 @@ ExplainNode(PlanState *planstate, List *ancestors,
 				show_buffer_usage(es, &instrument->bufusage);
 			if (es->wal)
 				show_wal_usage(es, &instrument->walusage);
-
-			/* show prefetch info for the given worker */
-			show_worker_io_info(planstate, es, n);
+			if (es->io)
+				show_io_usage(planstate, es, n);
 
 			ExplainCloseWorker(n, es);
 		}
@@ -3998,14 +3997,74 @@ show_tidbitmap_info(BitmapHeapScanState *planstate, ExplainState *es)
 	}
 }
 
+static void
+print_io_usage(ExplainState *es, TableScanStats stats)
+{
+	/* don't print stats if there's nothing to report */
+	if (stats->prefetch_count > 0)
+	{
+		if (es->format == EXPLAIN_FORMAT_TEXT)
+		{
+			/* prefetch distance info */
+			ExplainIndentText(es);
+			appendStringInfo(es->str, "Prefetch: avg=%.3f max=%d capacity=%d",
+							 (stats->distance_sum * 1.0 / stats->prefetch_count),
+							 stats->distance_max,
+							 stats->distance_capacity);
+			appendStringInfoChar(es->str, '\n');
+
+			/* prefetch I/O info (only if there were actual I/Os) */
+			if (stats->io_count > 0)
+			{
+				ExplainIndentText(es);
+				appendStringInfo(es->str, "I/O: stalls=%" PRIu64,
+								 stats->stall_count);
+
+				appendStringInfo(es->str, " size=%.3f inprogress=%.3f",
+								 (stats->io_nblocks * 1.0 / stats->io_count),
+								 (stats->io_in_progress * 1.0 / stats->io_count));
+
+				appendStringInfoChar(es->str, '\n');
+			}
+		}
+		else
+		{
+			ExplainOpenGroup("Prefetch", "Prefetch", true, es);
+
+			ExplainPropertyFloat("Average Distance", NULL,
+								 (stats->distance_sum * 1.0 / stats->prefetch_count), 3, es);
+			ExplainPropertyInteger("Max Distance", NULL,
+								   stats->distance_max, es);
+			ExplainPropertyInteger("Capacity", NULL,
+								   stats->distance_capacity, es);
+
+			ExplainCloseGroup("Prefetch", "Prefetch", true, es);
+
+			if (stats->io_count > 0)
+			{
+				ExplainOpenGroup("I/O", "I/O", true, es);
+
+				ExplainPropertyUInteger("Stalls", NULL,
+										stats->stall_count, es);
+				ExplainPropertyFloat("Average IO Size", NULL,
+									 (stats->io_nblocks * 1.0 / stats->io_count), 3, es);
+				ExplainPropertyFloat("Average IOs In Progress", NULL,
+									 (stats->io_in_progress * 1.0 / stats->io_count), 3, es);
+
+				ExplainCloseGroup("I/O", "I/O", true, es);
+			}
+		}
+	}
+}
+
 /*
- * show_scan_io_info
+ * show_scan_io_usage
  *		show info about prefetching for a seq/bitmap scan
  *
  * Shows summary of stats for leader and workers (if any).
  */
 static void
-show_scan_io_info(ScanState *planstate, ExplainState *es)
+show_scan_io_usage(ScanState *planstate, ExplainState *es)
 {
 	Plan	   *plan = planstate->ps.plan;
 	TableScanStats	leader_stats;
@@ -4044,17 +4103,7 @@ show_scan_io_info(ScanState *planstate, ExplainState *es)
 					for (int i = 0; i < sinstrument->num_workers; ++i)
 					{
 						SeqScanInstrumentation *winstrument = &sinstrument->sinstrument[i];
-
-						stats.prefetch_count += winstrument->stream.prefetch_count;
-						stats.distance_sum += winstrument->stream.distance_sum;
-						if (winstrument->stream.distance_max > stats.distance_max)
-							stats.distance_max = winstrument->stream.distance_max;
-						if (winstrument->stream.distance_capacity > stats.distance_capacity)
-							stats.distance_capacity = winstrument->stream.distance_capacity;
-						stats.stall_count += winstrument->stream.stall_count;
-						stats.io_count += winstrument->stream.io_count;
-						stats.io_nblocks += winstrument->stream.io_nblocks;
-						stats.io_in_progress += winstrument->stream.io_in_progress;
+						ACCUMULATE_TABLE_STATS(&stats, &winstrument->io);
 					}
 				}
 
@@ -4071,17 +4120,7 @@ show_scan_io_info(ScanState *planstate, ExplainState *es)
 					for (int i = 0; i < sinstrument->num_workers; ++i)
 					{
 						BitmapHeapScanInstrumentation *winstrument = &sinstrument->sinstrument[i];
-
-						stats.prefetch_count += winstrument->stream.prefetch_count;
-						stats.distance_sum += winstrument->stream.distance_sum;
-						if (winstrument->stream.distance_max > stats.distance_max)
-							stats.distance_max = winstrument->stream.distance_max;
-						if (winstrument->stream.distance_capacity > stats.distance_capacity)
-							stats.distance_capacity = winstrument->stream.distance_capacity;
-						stats.stall_count += winstrument->stream.stall_count;
-						stats.io_count += winstrument->stream.io_count;
-						stats.io_nblocks += winstrument->stream.io_nblocks;
-						stats.io_in_progress += winstrument->stream.io_in_progress;
+						ACCUMULATE_TABLE_STATS(&stats, &winstrument->io);
 					}
 				}
 
@@ -4092,73 +4131,23 @@ show_scan_io_info(ScanState *planstate, ExplainState *es)
 			return;
 	}
 
-	/* don't print anything without prefetching */
-	if (stats.prefetch_count > 0)
-	{
-		if (es->format == EXPLAIN_FORMAT_TEXT)
-		{
-			/* prefetch distance info */
-			ExplainIndentText(es);
-			appendStringInfo(es->str, "Prefetch: avg=%.3f max=%d capacity=%d",
-							 (stats.distance_sum * 1.0 / stats.prefetch_count),
-							 stats.distance_max,
-							 stats.distance_capacity);
-			appendStringInfoChar(es->str, '\n');
-
-			/* prefetch I/O info (only if there were actual I/Os) */
-			if (stats.stall_count > 0 || stats.io_count > 0)
-			{
-				ExplainIndentText(es);
-				appendStringInfo(es->str, "I/O: stalls=%" PRIu64,
-								 stats.stall_count);
-
-				if (stats.io_count > 0)
-				{
-					appendStringInfo(es->str, " size=%.3f inprogress=%.3f",
-									 (stats.io_nblocks * 1.0 / stats.io_count),
-									 (stats.io_in_progress * 1.0 / stats.io_count));
-				}
-
-				appendStringInfoChar(es->str, '\n');
-			}
-		}
-		else
-		{
-			ExplainOpenGroup("Prefetch", "I/O", true, es);
-
-			ExplainPropertyFloat("Average Distance", NULL,
-								 (stats.distance_sum * 1.0 / stats.prefetch_count), 3, es);
-			ExplainPropertyInteger("Max Distance", NULL,
-								   stats.distance_max, es);
-			ExplainPropertyInteger("Capacity", NULL,
-								   stats.distance_capacity, es);
-			ExplainPropertyUInteger("Stalls", NULL,
-									stats.stall_count, es);
-
-			if (stats.io_count > 0)
-			{
-				ExplainPropertyFloat("Average IO Size", NULL,
-									 (stats.io_nblocks * 1.0 / stats.io_count), 3, es);
-				ExplainPropertyFloat("Average IOs In Progress", NULL,
-									 (stats.io_in_progress * 1.0 / stats.io_count), 3, es);
-			}
-
-			ExplainCloseGroup("Prefetch", "I/O", true, es);
-		}
-	}
+	print_io_usage(es, &stats);
 }
 
 /*
- * show_io_worker_info
- *		show info about prefetching for a single worker
+ * show_io_usage
+ *		show info about I/O prefetching for a single worker
  *
  * Shows prefetching stats for a parallel scan worker.
  */
 static void
-show_worker_io_info(PlanState *planstate, ExplainState *es, int worker)
+show_io_usage(PlanState *planstate, ExplainState *es, int worker)
 {
 	Plan	   *plan = planstate->plan;
-	ReadStreamInstrumentation *stats = NULL;
+	IOStats	   *stats = NULL;
+
+	// XXX
+	TableScanStatsData	tmp;
 
 	if (!es->io)
 		return;
@@ -4172,7 +4161,7 @@ show_worker_io_info(PlanState *planstate, ExplainState *es, int worker)
 				SharedBitmapHeapInstrumentation *sinstrument = state->sinstrument;
 				BitmapHeapScanInstrumentation *instrument = &sinstrument->sinstrument[worker];
 
-				stats = &instrument->stream;
+				stats = &instrument->io;
 
 				break;
 			}
@@ -4182,7 +4171,7 @@ show_worker_io_info(PlanState *planstate, ExplainState *es, int worker)
 				SharedSeqScanInstrumentation *sinstrument = state->sinstrument;
 				SeqScanInstrumentation *instrument = &sinstrument->sinstrument[worker];
 
-				stats = &instrument->stream;
+				stats = &instrument->io;
 
 				break;
 			}
@@ -4191,60 +4180,17 @@ show_worker_io_info(PlanState *planstate, ExplainState *es, int worker)
 			return;
 	}
 
-	/* don't print stats if there's nothing to report */
-	if (stats->prefetch_count > 0)
-	{
-		if (es->format == EXPLAIN_FORMAT_TEXT)
-		{
-			/* prefetch distance info */
-			ExplainIndentText(es);
-			appendStringInfo(es->str, "Prefetch: avg=%.3f max=%d capacity=%d",
-							 (stats->distance_sum * 1.0 / stats->prefetch_count),
-							 stats->distance_max,
-							 stats->distance_capacity);
-			appendStringInfoChar(es->str, '\n');
-
-			/* prefetch I/O info (only if there were actual I/Os) */
-			if (stats->stall_count > 0 || stats->io_count > 0)
-			{
-				ExplainIndentText(es);
-				appendStringInfo(es->str, "I/O: stalls=%" PRIu64,
-								 stats->stall_count);
-
-				if (stats->io_count > 0)
-				{
-					appendStringInfo(es->str, " size=%.3f inprogress=%.3f",
-									 (stats->io_nblocks * 1.0 / stats->io_count),
-									 (stats->io_in_progress * 1.0 / stats->io_count));
-				}
-
-				appendStringInfoChar(es->str, '\n');
-			}
-		}
-		else
-		{
-			ExplainOpenGroup("Prefetch", "I/O", true, es);
-
-			ExplainPropertyFloat("Average Distance", NULL,
-								 (stats->distance_sum * 1.0 / stats->prefetch_count), 3, es);
-			ExplainPropertyInteger("Max Distance", NULL,
-								   stats->distance_max, es);
-			ExplainPropertyInteger("Capacity", NULL,
-								   stats->distance_capacity, es);
-			ExplainPropertyUInteger("Stalls", NULL,
-									stats->stall_count, es);
-
-			if (stats->io_count > 0)
-			{
-				ExplainPropertyFloat("Average IO Size", NULL,
-									 (stats->io_nblocks * 1.0 / stats->io_count), 3, es);
-				ExplainPropertyFloat("Average IOs In Progress", NULL,
-									 (stats->io_in_progress * 1.0 / stats->io_count), 3, es);
-			}
-
-			ExplainCloseGroup("Prefetch", "I/O", true, es);
-		}
-	}
+	/* XXX convert to TableScanStats */
+	tmp.distance_capacity = stats->distance_capacity;
+	tmp.distance_max = stats->distance_max;
+	tmp.distance_sum = stats->distance_sum;
+	tmp.io_count = stats->io_count;
+	tmp.io_in_progress = stats->io_in_progress;
+	tmp.io_nblocks = stats->io_nblocks;
+	tmp.prefetch_count = stats->prefetch_count;
+	tmp.stall_count = stats->stall_count;
+
+	print_io_usage(es, &tmp);
 }
 
 /*
diff --git a/src/backend/commands/explain_state.c b/src/backend/commands/explain_state.c
index f5cbdd21aaa..3d5f92bfa91 100644
--- a/src/backend/commands/explain_state.c
+++ b/src/backend/commands/explain_state.c
@@ -79,6 +79,7 @@ ParseExplainOptionList(ExplainState *es, List *options, ParseState *pstate)
 	ListCell   *lc;
 	bool		timing_set = false;
 	bool		buffers_set = false;
+	bool		io_set = false;
 	bool		summary_set = false;
 
 	/* Parse options list. */
@@ -161,6 +162,7 @@ ParseExplainOptionList(ExplainState *es, List *options, ParseState *pstate)
 		}
 		else if (strcmp(opt->defname, "io") == 0)
 		{
+			io_set = true;
 			es->io = defGetBoolean(opt);
 		}
 		else if (!ApplyExtensionExplainOption(es, opt, pstate))
@@ -183,6 +185,9 @@ ParseExplainOptionList(ExplainState *es, List *options, ParseState *pstate)
 	/* if the buffers was not set explicitly, set default value */
 	es->buffers = (buffers_set) ? es->buffers : es->analyze;
 
+	/* if the IO was not set explicitly, set default value */
+	es->io = (io_set) ? es->io : es->analyze;
+
 	/* check that timing is used with EXPLAIN ANALYZE */
 	if (es->timing && !es->analyze)
 		ereport(ERROR,
diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c
index bf9af7596ce..0f1459f11a4 100644
--- a/src/backend/executor/nodeBitmapHeapscan.c
+++ b/src/backend/executor/nodeBitmapHeapscan.c
@@ -333,16 +333,7 @@ ExecEndBitmapHeapScan(BitmapHeapScanState *node)
 		/* collect prefetch info for this process from the read_stream */
 		if ((stats = table_scan_stats(node->ss.ss_currentScanDesc)) != NULL)
 		{
-			si->stream.prefetch_count += stats->prefetch_count;
-			si->stream.distance_sum += stats->distance_sum;
-			if (stats->distance_max > si->stream.distance_max)
-				si->stream.distance_max = stats->distance_max;
-			if (stats->distance_capacity > si->stream.distance_capacity)
-				si->stream.distance_capacity = stats->distance_capacity;
-			si->stream.stall_count += stats->stall_count;
-			si->stream.io_count += stats->io_count;
-			si->stream.io_nblocks += stats->io_nblocks;
-			si->stream.io_in_progress += stats->io_in_progress;
+			ACCUMULATE_TABLE_STATS(stats, &si->io);
 		}
 	}
 
diff --git a/src/backend/executor/nodeSeqscan.c b/src/backend/executor/nodeSeqscan.c
index 7992946a5be..4fa85a1b6bc 100644
--- a/src/backend/executor/nodeSeqscan.c
+++ b/src/backend/executor/nodeSeqscan.c
@@ -319,16 +319,7 @@ ExecEndSeqScan(SeqScanState *node)
 		/* collect prefetch info for this process from the read_stream */
 		if ((stats = table_scan_stats(node->ss.ss_currentScanDesc)) != NULL)
 		{
-			si->stream.prefetch_count += stats->prefetch_count;
-			si->stream.distance_sum += stats->distance_sum;
-			if (stats->distance_max > si->stream.distance_max)
-				si->stream.distance_max = stats->distance_max;
-			if (stats->distance_capacity > si->stream.distance_capacity)
-				si->stream.distance_capacity = stats->distance_capacity;
-			si->stream.stall_count += stats->stall_count;
-			si->stream.io_count += stats->io_count;
-			si->stream.io_nblocks += stats->io_nblocks;
-			si->stream.io_in_progress += stats->io_in_progress;
+			ACCUMULATE_TABLE_STATS(stats, &si->io);
 		}
 	}
 
diff --git a/src/backend/storage/aio/read_stream.c b/src/backend/storage/aio/read_stream.c
index f560047afd6..faa52ca4b2c 100644
--- a/src/backend/storage/aio/read_stream.c
+++ b/src/backend/storage/aio/read_stream.c
@@ -108,8 +108,8 @@ struct ReadStream
 	bool		advice_enabled;
 	bool		temporary;
 
-	/* stats counters */
-	ReadStreamInstrumentation stats;
+	/* scan stats counters */
+	IOStats		stats;
 
 	/*
 	 * One-block buffer to support 'ungetting' a block number, to resolve flow
@@ -177,8 +177,7 @@ block_range_read_stream_cb(ReadStream *stream,
 }
 
 /*
- * read_stream_update_stats_prefetch
- *		update read_stream stats with current pinned buffer depth
+ * Update stream stats with current pinned buffer depth.
  *
  * Called once per buffer returned to the consumer in read_stream_next_buffer().
  * Records the number of pinned buffers at that moment, so we can compute the
@@ -194,8 +193,7 @@ read_stream_update_stats_prefetch(ReadStream *stream)
 }
 
 /*
- * read_stream_update_stats_io
- *		update read_stream stats about size of I/O requests
+ * Update stream stats about size of I/O requests.
  *
  * We count the number of I/O requests, size of requests (counted in blocks)
  * and number of in-progress I/Os.
@@ -208,6 +206,12 @@ read_stream_update_stats_io(ReadStream *stream, int nblocks, int in_progress)
 	stream->stats.io_in_progress += in_progress;
 }
 
+static inline void
+read_stream_update_stats_stall(ReadStream *stream)
+{
+	stream->stats.stall_count++;
+}
+
 /*
  * Ask the callback which block it would like us to read next, with a one block
  * buffer in front to allow read_stream_unget_block() to work.
@@ -743,7 +747,7 @@ read_stream_begin_impl(int flags,
 	stream->temporary = SmgrIsTemp(smgr);
 
 	/* zero the stats, then set capacity */
-	memset(&stream->stats, 0, sizeof(ReadStreamInstrumentation));
+	memset(&stream->stats, 0, sizeof(IOStats));
 	stream->stats.distance_capacity = max_pinned_buffers;
 
 	/*
@@ -907,6 +911,9 @@ read_stream_next_buffer(ReadStream *stream, void **per_buffer_data)
 
 			/* update I/O stats */
 			read_stream_update_stats_io(stream, 1, stream->ios_in_progress);
+
+			/* update prefetch distance */
+			read_stream_update_stats_prefetch(stream);
 		}
 		else
 		{
@@ -918,7 +925,6 @@ read_stream_next_buffer(ReadStream *stream, void **per_buffer_data)
 		}
 
 		stream->fast_path = false;
-		read_stream_update_stats_prefetch(stream);
 		return buffer;
 	}
 #endif
@@ -974,7 +980,7 @@ read_stream_next_buffer(ReadStream *stream, void **per_buffer_data)
 
 		/* Count it as a stall if we need to wait for IO */
 		if (needed_wait)
-			stream->stats.stall_count += 1;
+			read_stream_update_stats_stall(stream);
 
 		Assert(stream->ios_in_progress > 0);
 		stream->ios_in_progress--;
@@ -1175,7 +1181,7 @@ read_stream_end(ReadStream *stream)
 }
 
 /* return the prefetch stats for the read_stream */
-ReadStreamInstrumentation
+IOStats
 read_stream_prefetch_stats(ReadStream *stream)
 {
 	return stream->stats;
diff --git a/src/include/access/relscan.h b/src/include/access/relscan.h
index cada9f28bd8..c0488987b2d 100644
--- a/src/include/access/relscan.h
+++ b/src/include/access/relscan.h
@@ -141,6 +141,20 @@ typedef struct TableScanStatsData
 } TableScanStatsData;
 typedef struct TableScanStatsData *TableScanStats;
 
+#define ACCUMULATE_TABLE_STATS(dst, src) \
+	do { \
+		(dst)->prefetch_count += (src)->prefetch_count; \
+		(dst)->distance_sum += (src)->distance_sum; \
+		if ((src)->distance_max > (dst)->distance_max) \
+			(dst)->distance_max = (src)->distance_max; \
+		if ((src)->distance_capacity > (dst)->distance_capacity) \
+			(dst)->distance_capacity = (src)->distance_capacity; \
+		(dst)->stall_count += (src)->stall_count; \
+		(dst)->io_count += (src)->io_count; \
+		(dst)->io_nblocks += (src)->io_nblocks; \
+		(dst)->io_in_progress += (src)->io_in_progress; \
+	} while (0)
+
 /*
  * Base class for fetches from a table via an index. This is the base-class
  * for such scans, which needs to be embedded in the respective struct for
diff --git a/src/include/executor/instrument_node.h b/src/include/executor/instrument_node.h
index d94dbbc917d..cda00ad40e9 100644
--- a/src/include/executor/instrument_node.h
+++ b/src/include/executor/instrument_node.h
@@ -44,7 +44,7 @@ typedef struct SharedAggInfo
  *	Instrumentation information about read streams
  * ---------------------
  */
-typedef struct ReadStreamInstrumentation
+typedef struct IOStats
 {
 	/* number of buffers returned to consumer (for averaging distance) */
 	uint64		prefetch_count;
@@ -65,7 +65,7 @@ typedef struct ReadStreamInstrumentation
 	uint64		io_count;		/* number of I/Os */
 	uint64		io_nblocks;		/* sum of blocks for all I/Os */
 	uint64		io_in_progress;	/* sum of in-progress I/Os */
-} ReadStreamInstrumentation;
+} IOStats;
 
 
 /* ---------------------
@@ -74,7 +74,7 @@ typedef struct ReadStreamInstrumentation
  */
 typedef struct SeqScanInstrumentation
 {
-	ReadStreamInstrumentation	stream;
+	IOStats		io;
 } SeqScanInstrumentation;
 
 /*
@@ -113,7 +113,7 @@ typedef struct BitmapHeapScanInstrumentation
 {
 	uint64		exact_pages;
 	uint64		lossy_pages;
-	ReadStreamInstrumentation	stream;
+	IOStats		io;
 } BitmapHeapScanInstrumentation;
 
 /*
diff --git a/src/include/storage/read_stream.h b/src/include/storage/read_stream.h
index ec396db5369..0676bdc9b14 100644
--- a/src/include/storage/read_stream.h
+++ b/src/include/storage/read_stream.h
@@ -65,7 +65,7 @@
 
 struct ReadStream;
 typedef struct ReadStream ReadStream;
-typedef struct ReadStreamInstrumentation ReadStreamInstrumentation;
+typedef struct IOStats IOStats;
 
 /* for block_range_read_stream_cb */
 typedef struct BlockRangeReadStreamPrivate
@@ -105,6 +105,6 @@ extern void read_stream_resume(ReadStream *stream);
 extern void read_stream_reset(ReadStream *stream);
 extern void read_stream_end(ReadStream *stream);
 
-extern ReadStreamInstrumentation read_stream_prefetch_stats(ReadStream *stream);
+extern IOStats read_stream_prefetch_stats(ReadStream *stream);
 
 #endif							/* READ_STREAM_H */
diff --git a/src/test/regress/expected/explain.out b/src/test/regress/expected/explain.out
index 7c1f26b182c..2d247f73c14 100644
--- a/src/test/regress/expected/explain.out
+++ b/src/test/regress/expected/explain.out
@@ -23,6 +23,10 @@ begin
         -- Ignore text-mode buffers output because it varies depending
         -- on the system state
         CONTINUE WHEN (ln ~ ' +Buffers: .*');
+        -- Ignore text-mode prefetch and I/O output because it varies
+        -- depending on the system state
+        CONTINUE WHEN (ln ~ ' +Prefetch: .*');
+        CONTINUE WHEN (ln ~ ' +I/O: .*');
         -- Ignore text-mode "Planning:" line because whether it's output
         -- varies depending on the system state
         CONTINUE WHEN (ln = 'Planning:');
@@ -68,7 +72,7 @@ select explain_filter('explain select * from int8_tbl i8');
  Seq Scan on int8_tbl i8  (cost=N.N..N.N rows=N width=N)
 (1 row)
 
-select explain_filter('explain (analyze, buffers off) select * from int8_tbl i8');
+select explain_filter('explain (analyze, buffers off, io off) select * from int8_tbl i8');
                                          explain_filter                                          
 -------------------------------------------------------------------------------------------------
  Seq Scan on int8_tbl i8  (cost=N.N..N.N rows=N width=N) (actual time=N.N..N.N rows=N.N loops=N)
@@ -76,7 +80,7 @@ select explain_filter('explain (analyze, buffers off) select * from int8_tbl i8'
  Execution Time: N.N ms
 (3 rows)
 
-select explain_filter('explain (analyze, buffers off, verbose) select * from int8_tbl i8');
+select explain_filter('explain (analyze, buffers off, io off, verbose) select * from int8_tbl i8');
                                              explain_filter                                             
 --------------------------------------------------------------------------------------------------------
  Seq Scan on public.int8_tbl i8  (cost=N.N..N.N rows=N width=N) (actual time=N.N..N.N rows=N.N loops=N)
@@ -93,7 +97,7 @@ select explain_filter('explain (analyze, buffers, format text) select * from int
  Execution Time: N.N ms
 (3 rows)
 
-select explain_filter('explain (analyze, buffers, format xml) select * from int8_tbl i8');
+select explain_filter('explain (analyze, buffers, io off, format xml) select * from int8_tbl i8');
                      explain_filter                     
 --------------------------------------------------------
  <explain xmlns="http://www.postgresql.org/N/explain"> +
@@ -144,7 +148,7 @@ select explain_filter('explain (analyze, buffers, format xml) select * from int8
  </explain>
 (1 row)
 
-select explain_filter('explain (analyze, serialize, buffers, format yaml) select * from int8_tbl i8');
+select explain_filter('explain (analyze, serialize, buffers, io off, format yaml) select * from int8_tbl i8');
         explain_filter         
 -------------------------------
  - Plan:                      +
@@ -310,6 +314,11 @@ select explain_filter('explain (analyze, buffers, format json) select * from int
        "Actual Rows": N.N,          +
        "Actual Loops": N,           +
        "Disabled": false,           +
+       "Prefetch": {                +
+         "Average Distance": N.N,   +
+         "Max Distance": N,         +
+         "Capacity": N              +
+       },                           +
        "Shared Hit Blocks": N,      +
        "Shared Read Blocks": N,     +
        "Shared Dirtied Blocks": N,  +
@@ -396,7 +405,7 @@ select explain_filter('explain (memory) select * from int8_tbl i8');
    Memory: used=NkB  allocated=NkB
 (2 rows)
 
-select explain_filter('explain (memory, analyze, buffers off) select * from int8_tbl i8');
+select explain_filter('explain (memory, analyze, buffers off, io off) select * from int8_tbl i8');
                                          explain_filter                                          
 -------------------------------------------------------------------------------------------------
  Seq Scan on int8_tbl i8  (cost=N.N..N.N rows=N width=N) (actual time=N.N..N.N rows=N.N loops=N)
@@ -445,6 +454,11 @@ select explain_filter('explain (memory, analyze, format json) select * from int8
        "Actual Rows": N.N,         +
        "Actual Loops": N,          +
        "Disabled": false,          +
+       "Prefetch": {               +
+         "Average Distance": N.N,  +
+         "Max Distance": N,        +
+         "Capacity": N             +
+       },                          +
        "Shared Hit Blocks": N,     +
        "Shared Read Blocks": N,    +
        "Shared Dirtied Blocks": N, +
@@ -568,6 +582,11 @@ select jsonb_pretty(
                              ],                             +
                              "Schema": "public",            +
                              "Disabled": false,             +
+                             "Prefetch": {                  +
+                                 "Capacity": 0,             +
+                                 "Max Distance": 0,         +
+                                 "Average Distance": 0.0    +
+                             },                             +
                              "Node Type": "Seq Scan",       +
                              "Plan Rows": 0,                +
                              "Plan Width": 0,               +
@@ -744,7 +763,7 @@ select explain_filter('explain (verbose) create table test_ctas as select 1');
 (3 rows)
 
 -- Test SERIALIZE option
-select explain_filter('explain (analyze,buffers off,serialize) select * from int8_tbl i8');
+select explain_filter('explain (analyze,buffers off,io off,serialize) select * from int8_tbl i8');
                                          explain_filter                                          
 -------------------------------------------------------------------------------------------------
  Seq Scan on int8_tbl i8  (cost=N.N..N.N rows=N width=N) (actual time=N.N..N.N rows=N.N loops=N)
@@ -772,7 +791,7 @@ select explain_filter('explain (analyze,serialize binary,buffers,timing) select
 (4 rows)
 
 -- this tests an edge case where we have no data to return
-select explain_filter('explain (analyze,buffers off,serialize) create temp table explain_temp as select * from int8_tbl i8');
+select explain_filter('explain (analyze,buffers off,io off,serialize) create temp table explain_temp as select * from int8_tbl i8');
                                          explain_filter                                          
 -------------------------------------------------------------------------------------------------
  Seq Scan on int8_tbl i8  (cost=N.N..N.N rows=N width=N) (actual time=N.N..N.N rows=N.N loops=N)
@@ -782,7 +801,7 @@ select explain_filter('explain (analyze,buffers off,serialize) create temp table
 (4 rows)
 
 -- Test tuplestore storage usage in Window aggregate (memory case)
-select explain_filter('explain (analyze,buffers off,costs off) select sum(n) over() from generate_series(1,10) a(n)');
+select explain_filter('explain (analyze,buffers off,io off,costs off) select sum(n) over() from generate_series(1,10) a(n)');
                                   explain_filter                                  
 ----------------------------------------------------------------------------------
  WindowAgg (actual time=N.N..N.N rows=N.N loops=N)
@@ -795,7 +814,7 @@ select explain_filter('explain (analyze,buffers off,costs off) select sum(n) ove
 
 -- Test tuplestore storage usage in Window aggregate (disk case)
 set work_mem to 64;
-select explain_filter('explain (analyze,buffers off,costs off) select sum(n) over() from generate_series(1,2500) a(n)');
+select explain_filter('explain (analyze,buffers off,io off,costs off) select sum(n) over() from generate_series(1,2500) a(n)');
                                   explain_filter                                  
 ----------------------------------------------------------------------------------
  WindowAgg (actual time=N.N..N.N rows=N.N loops=N)
@@ -807,7 +826,7 @@ select explain_filter('explain (analyze,buffers off,costs off) select sum(n) ove
 (6 rows)
 
 -- Test tuplestore storage usage in Window aggregate (memory and disk case, final result is disk)
-select explain_filter('explain (analyze,buffers off,costs off) select sum(n) over(partition by m) from (SELECT n < 3 as m, n from generate_series(1,2500) a(n))');
+select explain_filter('explain (analyze,buffers off,io off,costs off) select sum(n) over(partition by m) from (SELECT n < 3 as m, n from generate_series(1,2500) a(n))');
                                      explain_filter                                     
 ----------------------------------------------------------------------------------------
  WindowAgg (actual time=N.N..N.N rows=N.N loops=N)
diff --git a/src/test/regress/expected/incremental_sort.out b/src/test/regress/expected/incremental_sort.out
index 1e6e020fea8..55d5a52d96b 100644
--- a/src/test/regress/expected/incremental_sort.out
+++ b/src/test/regress/expected/incremental_sort.out
@@ -39,7 +39,7 @@ declare
   line text;
 begin
   for line in
-    execute 'explain (analyze, costs off, summary off, timing off, buffers off) ' || query
+    execute 'explain (analyze, costs off, summary off, timing off, buffers off, io off) ' || query
   loop
     out_line := regexp_replace(line, '\d+kB', 'NNkB', 'g');
     return next;
@@ -55,7 +55,7 @@ declare
   element jsonb;
   matching_nodes jsonb := '[]'::jsonb;
 begin
-  execute 'explain (analyze, costs off, summary off, timing off, buffers off, format ''json'') ' || query into strict elements;
+  execute 'explain (analyze, costs off, summary off, timing off, buffers off, io off, format ''json'') ' || query into strict elements;
   while jsonb_array_length(elements) > 0 loop
     element := elements->0;
     elements := elements - 0;
diff --git a/src/test/regress/expected/memoize.out b/src/test/regress/expected/memoize.out
index 00c30b91459..425aed4d749 100644
--- a/src/test/regress/expected/memoize.out
+++ b/src/test/regress/expected/memoize.out
@@ -10,7 +10,7 @@ declare
     ln text;
 begin
     for ln in
-        execute format('explain (analyze, costs off, summary off, timing off, buffers off) %s',
+        execute format('explain (analyze, costs off, summary off, timing off, buffers off, io off) %s',
             query)
     loop
         if hide_hitmiss = true then
diff --git a/src/test/regress/expected/merge.out b/src/test/regress/expected/merge.out
index 9cb1d87066a..f1331c307d3 100644
--- a/src/test/regress/expected/merge.out
+++ b/src/test/regress/expected/merge.out
@@ -1623,7 +1623,7 @@ $$
 DECLARE ln text;
 BEGIN
     FOR ln IN
-        EXECUTE 'explain (analyze, timing off, summary off, costs off, buffers off) ' ||
+        EXECUTE 'explain (analyze, timing off, summary off, costs off, buffers off, io off) ' ||
 		  query
     LOOP
         ln := regexp_replace(ln, '(Memory( Usage)?|Buckets|Batches): \S*',  '\1: xxx', 'g');
diff --git a/src/test/regress/expected/partition_prune.out b/src/test/regress/expected/partition_prune.out
index deacdd75807..1332cd0e646 100644
--- a/src/test/regress/expected/partition_prune.out
+++ b/src/test/regress/expected/partition_prune.out
@@ -11,7 +11,7 @@ declare
     ln text;
 begin
     for ln in
-        execute format('explain (analyze, costs off, summary off, timing off, buffers off) %s',
+        execute format('explain (analyze, costs off, summary off, timing off, buffers off, io off) %s',
             query)
     loop
         ln := regexp_replace(ln, 'Maximum Storage: \d+', 'Maximum Storage: N');
@@ -2322,7 +2322,8 @@ explain (analyze, costs off, summary off, timing off, buffers off) select * from
    Subplans Removed: 3
    ->  Seq Scan on list_part1 list_part_1 (actual rows=1.00 loops=1)
          Filter: (a = list_part_fn(1))
-(4 rows)
+         Prefetch: avg=1.000 max=1 capacity=94
+(5 rows)
 
 -- Ensure pruning does not take place when the function has a Var parameter
 explain (analyze, costs off, summary off, timing off, buffers off) select * from list_part where a = list_part_fn(a);
@@ -2331,13 +2332,17 @@ explain (analyze, costs off, summary off, timing off, buffers off) select * from
  Append (actual rows=4.00 loops=1)
    ->  Seq Scan on list_part1 list_part_1 (actual rows=1.00 loops=1)
          Filter: (a = list_part_fn(a))
+         Prefetch: avg=1.000 max=1 capacity=94
    ->  Seq Scan on list_part2 list_part_2 (actual rows=1.00 loops=1)
          Filter: (a = list_part_fn(a))
+         Prefetch: avg=1.000 max=1 capacity=94
    ->  Seq Scan on list_part3 list_part_3 (actual rows=1.00 loops=1)
          Filter: (a = list_part_fn(a))
+         Prefetch: avg=1.000 max=1 capacity=94
    ->  Seq Scan on list_part4 list_part_4 (actual rows=1.00 loops=1)
          Filter: (a = list_part_fn(a))
-(9 rows)
+         Prefetch: avg=1.000 max=1 capacity=94
+(13 rows)
 
 -- Ensure pruning does not take place when the expression contains a Var.
 explain (analyze, costs off, summary off, timing off, buffers off) select * from list_part where a = list_part_fn(1) + a;
@@ -2347,16 +2352,20 @@ explain (analyze, costs off, summary off, timing off, buffers off) select * from
    ->  Seq Scan on list_part1 list_part_1 (actual rows=0.00 loops=1)
          Filter: (a = (list_part_fn(1) + a))
          Rows Removed by Filter: 1
+         Prefetch: avg=1.000 max=1 capacity=94
    ->  Seq Scan on list_part2 list_part_2 (actual rows=0.00 loops=1)
          Filter: (a = (list_part_fn(1) + a))
          Rows Removed by Filter: 1
+         Prefetch: avg=1.000 max=1 capacity=94
    ->  Seq Scan on list_part3 list_part_3 (actual rows=0.00 loops=1)
          Filter: (a = (list_part_fn(1) + a))
          Rows Removed by Filter: 1
+         Prefetch: avg=1.000 max=1 capacity=94
    ->  Seq Scan on list_part4 list_part_4 (actual rows=0.00 loops=1)
          Filter: (a = (list_part_fn(1) + a))
          Rows Removed by Filter: 1
-(13 rows)
+         Prefetch: avg=1.000 max=1 capacity=94
+(17 rows)
 
 rollback;
 drop table list_part;
@@ -2524,6 +2533,7 @@ select explain_parallel_append('select avg(ab.a) from ab inner join lprt_a a on
                ->  Nested Loop (actual rows=N loops=N)
                      ->  Parallel Seq Scan on lprt_a a (actual rows=N loops=N)
                            Filter: (a = ANY ('{0,0,1}'::integer[]))
+                           Prefetch: avg=1.000 max=1 capacity=94
                      ->  Append (actual rows=N loops=N)
                            ->  Index Scan using ab_a1_b1_a_idx on ab_a1_b1 ab_1 (actual rows=N loops=N)
                                  Index Cond: (a = a.a)
@@ -2543,7 +2553,7 @@ select explain_parallel_append('select avg(ab.a) from ab inner join lprt_a a on
                                  Index Cond: (a = a.a)
                            ->  Index Scan using ab_a3_b3_a_idx on ab_a3_b3 ab_9 (never executed)
                                  Index Cond: (a = a.a)
-(27 rows)
+(28 rows)
 
 -- Ensure the same partitions are pruned when we make the nested loop
 -- parameter an Expr rather than a plain Param.
@@ -2558,6 +2568,7 @@ select explain_parallel_append('select avg(ab.a) from ab inner join lprt_a a on
                ->  Nested Loop (actual rows=N loops=N)
                      ->  Parallel Seq Scan on lprt_a a (actual rows=N loops=N)
                            Filter: (a = ANY ('{0,0,1}'::integer[]))
+                           Prefetch: avg=1.000 max=1 capacity=94
                      ->  Append (actual rows=N loops=N)
                            ->  Index Scan using ab_a1_b1_a_idx on ab_a1_b1 ab_1 (actual rows=N loops=N)
                                  Index Cond: (a = (a.a + 0))
@@ -2577,7 +2588,7 @@ select explain_parallel_append('select avg(ab.a) from ab inner join lprt_a a on
                                  Index Cond: (a = (a.a + 0))
                            ->  Index Scan using ab_a3_b3_a_idx on ab_a3_b3 ab_9 (never executed)
                                  Index Cond: (a = (a.a + 0))
-(27 rows)
+(28 rows)
 
 insert into lprt_a values(3),(3);
 select explain_parallel_append('select avg(ab.a) from ab inner join lprt_a a on ab.a = a.a where a.a in(1, 0, 3)');
@@ -2591,6 +2602,7 @@ select explain_parallel_append('select avg(ab.a) from ab inner join lprt_a a on
                ->  Nested Loop (actual rows=N loops=N)
                      ->  Parallel Seq Scan on lprt_a a (actual rows=N loops=N)
                            Filter: (a = ANY ('{1,0,3}'::integer[]))
+                           Prefetch: avg=1.000 max=1 capacity=94
                      ->  Append (actual rows=N loops=N)
                            ->  Index Scan using ab_a1_b1_a_idx on ab_a1_b1 ab_1 (actual rows=N loops=N)
                                  Index Cond: (a = a.a)
@@ -2610,7 +2622,7 @@ select explain_parallel_append('select avg(ab.a) from ab inner join lprt_a a on
                                  Index Cond: (a = a.a)
                            ->  Index Scan using ab_a3_b3_a_idx on ab_a3_b3 ab_9 (actual rows=N loops=N)
                                  Index Cond: (a = a.a)
-(27 rows)
+(28 rows)
 
 select explain_parallel_append('select avg(ab.a) from ab inner join lprt_a a on ab.a = a.a where a.a in(1, 0, 0)');
                                         explain_parallel_append                                         
@@ -2624,6 +2636,7 @@ select explain_parallel_append('select avg(ab.a) from ab inner join lprt_a a on
                      ->  Parallel Seq Scan on lprt_a a (actual rows=N loops=N)
                            Filter: (a = ANY ('{1,0,0}'::integer[]))
                            Rows Removed by Filter: N
+                           Prefetch: avg=1.000 max=1 capacity=94
                      ->  Append (actual rows=N loops=N)
                            ->  Index Scan using ab_a1_b1_a_idx on ab_a1_b1 ab_1 (actual rows=N loops=N)
                                  Index Cond: (a = a.a)
@@ -2643,7 +2656,7 @@ select explain_parallel_append('select avg(ab.a) from ab inner join lprt_a a on
                                  Index Cond: (a = a.a)
                            ->  Index Scan using ab_a3_b3_a_idx on ab_a3_b3 ab_9 (never executed)
                                  Index Cond: (a = a.a)
-(28 rows)
+(29 rows)
 
 delete from lprt_a where a = 1;
 select explain_parallel_append('select avg(ab.a) from ab inner join lprt_a a on ab.a = a.a where a.a in(1, 0, 0)');
@@ -2658,6 +2671,7 @@ select explain_parallel_append('select avg(ab.a) from ab inner join lprt_a a on
                      ->  Parallel Seq Scan on lprt_a a (actual rows=N loops=N)
                            Filter: (a = ANY ('{1,0,0}'::integer[]))
                            Rows Removed by Filter: N
+                           Prefetch: avg=1.000 max=1 capacity=94
                      ->  Append (actual rows=N loops=N)
                            ->  Index Scan using ab_a1_b1_a_idx on ab_a1_b1 ab_1 (never executed)
                                  Index Cond: (a = a.a)
@@ -2677,7 +2691,7 @@ select explain_parallel_append('select avg(ab.a) from ab inner join lprt_a a on
                                  Index Cond: (a = a.a)
                            ->  Index Scan using ab_a3_b3_a_idx on ab_a3_b3 ab_9 (never executed)
                                  Index Cond: (a = a.a)
-(28 rows)
+(29 rows)
 
 reset enable_hashjoin;
 reset enable_mergejoin;
@@ -2695,9 +2709,11 @@ select * from ab where a = (select max(a) from lprt_a) and b = (select max(a)-1
    InitPlan expr_1
      ->  Aggregate (actual rows=1.00 loops=1)
            ->  Seq Scan on lprt_a (actual rows=102.00 loops=1)
+                 Prefetch: avg=1.000 max=1 capacity=94
    InitPlan expr_2
      ->  Aggregate (actual rows=1.00 loops=1)
            ->  Seq Scan on lprt_a lprt_a_1 (actual rows=102.00 loops=1)
+                 Prefetch: avg=1.000 max=1 capacity=94
    ->  Bitmap Heap Scan on ab_a1_b1 ab_1 (never executed)
          Recheck Cond: (a = (InitPlan expr_1).col1)
          Filter: (b = (InitPlan expr_2).col1)
@@ -2752,7 +2768,7 @@ select * from ab where a = (select max(a) from lprt_a) and b = (select max(a)-1
          ->  Bitmap Index Scan on ab_a3_b3_a_idx (never executed)
                Index Cond: (a = (InitPlan expr_1).col1)
                Index Searches: 0
-(61 rows)
+(63 rows)
 
 -- Test run-time partition pruning with UNION ALL parents
 explain (analyze, costs off, summary off, timing off, buffers off)
@@ -2880,13 +2896,14 @@ explain (analyze, costs off, summary off, timing off, buffers off) execute ab_q6
    ->  Seq Scan on xy_1 (actual rows=0.00 loops=1)
          Filter: ((x = $1) AND (y = (InitPlan expr_1).col1))
          Rows Removed by Filter: 1
+         Prefetch: avg=1.000 max=1 capacity=94
    ->  Seq Scan on ab_a1_b1 ab_4 (never executed)
          Filter: ((a = $1) AND (b = (InitPlan expr_1).col1))
    ->  Seq Scan on ab_a1_b2 ab_5 (never executed)
          Filter: ((a = $1) AND (b = (InitPlan expr_1).col1))
    ->  Seq Scan on ab_a1_b3 ab_6 (never executed)
          Filter: ((a = $1) AND (b = (InitPlan expr_1).col1))
-(19 rows)
+(20 rows)
 
 -- Ensure we see just the xy_1 row.
 execute ab_q6(100);
@@ -3025,6 +3042,7 @@ select * from tbl1 join tprt on tbl1.col1 > tprt.col1;
 -----------------------------------------------------------------------------
  Nested Loop (actual rows=6.00 loops=1)
    ->  Seq Scan on tbl1 (actual rows=2.00 loops=1)
+         Prefetch: avg=1.000 max=1 capacity=94
    ->  Append (actual rows=3.00 loops=2)
          ->  Index Scan using tprt1_idx on tprt_1 (actual rows=2.00 loops=2)
                Index Cond: (col1 < tbl1.col1)
@@ -3044,7 +3062,7 @@ select * from tbl1 join tprt on tbl1.col1 > tprt.col1;
          ->  Index Scan using tprt6_idx on tprt_6 (never executed)
                Index Cond: (col1 < tbl1.col1)
                Index Searches: 0
-(21 rows)
+(22 rows)
 
 explain (analyze, costs off, summary off, timing off, buffers off)
 select * from tbl1 join tprt on tbl1.col1 = tprt.col1;
@@ -3052,6 +3070,7 @@ select * from tbl1 join tprt on tbl1.col1 = tprt.col1;
 -----------------------------------------------------------------------------
  Nested Loop (actual rows=2.00 loops=1)
    ->  Seq Scan on tbl1 (actual rows=2.00 loops=1)
+         Prefetch: avg=1.000 max=1 capacity=94
    ->  Append (actual rows=1.00 loops=2)
          ->  Index Scan using tprt1_idx on tprt_1 (never executed)
                Index Cond: (col1 = tbl1.col1)
@@ -3071,7 +3090,7 @@ select * from tbl1 join tprt on tbl1.col1 = tprt.col1;
          ->  Index Scan using tprt6_idx on tprt_6 (never executed)
                Index Cond: (col1 = tbl1.col1)
                Index Searches: 0
-(21 rows)
+(22 rows)
 
 select tbl1.col1, tprt.col1 from tbl1
 inner join tprt on tbl1.col1 > tprt.col1
@@ -3103,6 +3122,7 @@ select * from tbl1 inner join tprt on tbl1.col1 > tprt.col1;
 -----------------------------------------------------------------------------
  Nested Loop (actual rows=23.00 loops=1)
    ->  Seq Scan on tbl1 (actual rows=5.00 loops=1)
+         Prefetch: avg=1.000 max=1 capacity=94
    ->  Append (actual rows=4.60 loops=5)
          ->  Index Scan using tprt1_idx on tprt_1 (actual rows=2.00 loops=5)
                Index Cond: (col1 < tbl1.col1)
@@ -3122,7 +3142,7 @@ select * from tbl1 inner join tprt on tbl1.col1 > tprt.col1;
          ->  Index Scan using tprt6_idx on tprt_6 (never executed)
                Index Cond: (col1 < tbl1.col1)
                Index Searches: 0
-(21 rows)
+(22 rows)
 
 explain (analyze, costs off, summary off, timing off, buffers off)
 select * from tbl1 inner join tprt on tbl1.col1 = tprt.col1;
@@ -3130,6 +3150,7 @@ select * from tbl1 inner join tprt on tbl1.col1 = tprt.col1;
 -----------------------------------------------------------------------------
  Nested Loop (actual rows=3.00 loops=1)
    ->  Seq Scan on tbl1 (actual rows=5.00 loops=1)
+         Prefetch: avg=1.000 max=1 capacity=94
    ->  Append (actual rows=0.60 loops=5)
          ->  Index Scan using tprt1_idx on tprt_1 (never executed)
                Index Cond: (col1 = tbl1.col1)
@@ -3149,7 +3170,7 @@ select * from tbl1 inner join tprt on tbl1.col1 = tprt.col1;
          ->  Index Scan using tprt6_idx on tprt_6 (never executed)
                Index Cond: (col1 = tbl1.col1)
                Index Searches: 0
-(21 rows)
+(22 rows)
 
 select tbl1.col1, tprt.col1 from tbl1
 inner join tprt on tbl1.col1 > tprt.col1
@@ -3200,6 +3221,7 @@ select * from tbl1 join tprt on tbl1.col1 < tprt.col1;
 -----------------------------------------------------------------------------
  Nested Loop (actual rows=1.00 loops=1)
    ->  Seq Scan on tbl1 (actual rows=1.00 loops=1)
+         Prefetch: avg=1.000 max=1 capacity=94
    ->  Append (actual rows=1.00 loops=1)
          ->  Index Scan using tprt1_idx on tprt_1 (never executed)
                Index Cond: (col1 > tbl1.col1)
@@ -3219,7 +3241,7 @@ select * from tbl1 join tprt on tbl1.col1 < tprt.col1;
          ->  Index Scan using tprt6_idx on tprt_6 (actual rows=1.00 loops=1)
                Index Cond: (col1 > tbl1.col1)
                Index Searches: 1
-(21 rows)
+(22 rows)
 
 select tbl1.col1, tprt.col1 from tbl1
 inner join tprt on tbl1.col1 < tprt.col1
@@ -3238,6 +3260,7 @@ select * from tbl1 join tprt on tbl1.col1 = tprt.col1;
 -------------------------------------------------------------------
  Nested Loop (actual rows=0.00 loops=1)
    ->  Seq Scan on tbl1 (actual rows=1.00 loops=1)
+         Prefetch: avg=1.000 max=1 capacity=94
    ->  Append (actual rows=0.00 loops=1)
          ->  Index Scan using tprt1_idx on tprt_1 (never executed)
                Index Cond: (col1 = tbl1.col1)
@@ -3257,7 +3280,7 @@ select * from tbl1 join tprt on tbl1.col1 = tprt.col1;
          ->  Index Scan using tprt6_idx on tprt_6 (never executed)
                Index Cond: (col1 = tbl1.col1)
                Index Searches: 0
-(21 rows)
+(22 rows)
 
 select tbl1.col1, tprt.col1 from tbl1
 inner join tprt on tbl1.col1 = tprt.col1
@@ -3485,11 +3508,14 @@ select * from mc3p where a < 3 and abs(b) = 1;
  Append (actual rows=3.00 loops=1)
    ->  Seq Scan on mc3p0 mc3p_1 (actual rows=1.00 loops=1)
          Filter: ((a < 3) AND (abs(b) = 1))
+         Prefetch: avg=1.000 max=1 capacity=94
    ->  Seq Scan on mc3p1 mc3p_2 (actual rows=1.00 loops=1)
          Filter: ((a < 3) AND (abs(b) = 1))
+         Prefetch: avg=1.000 max=1 capacity=94
    ->  Seq Scan on mc3p2 mc3p_3 (actual rows=1.00 loops=1)
          Filter: ((a < 3) AND (abs(b) = 1))
-(7 rows)
+         Prefetch: avg=1.000 max=1 capacity=94
+(10 rows)
 
 --
 -- Check that pruning with composite range partitioning works correctly when
@@ -3508,7 +3534,8 @@ execute ps1(1);
      ->  Result (actual rows=1.00 loops=1)
    ->  Seq Scan on mc3p1 mc3p_1 (actual rows=1.00 loops=1)
          Filter: ((a = $1) AND (abs(b) < (InitPlan expr_1).col1))
-(6 rows)
+         Prefetch: avg=1.000 max=1 capacity=94
+(7 rows)
 
 deallocate ps1;
 prepare ps2 as
@@ -3523,9 +3550,11 @@ execute ps2(1);
      ->  Result (actual rows=1.00 loops=1)
    ->  Seq Scan on mc3p0 mc3p_1 (actual rows=1.00 loops=1)
          Filter: ((a <= $1) AND (abs(b) < (InitPlan expr_1).col1))
+         Prefetch: avg=1.000 max=1 capacity=94
    ->  Seq Scan on mc3p1 mc3p_2 (actual rows=1.00 loops=1)
          Filter: ((a <= $1) AND (abs(b) < (InitPlan expr_1).col1))
-(8 rows)
+         Prefetch: avg=1.000 max=1 capacity=94
+(10 rows)
 
 deallocate ps2;
 drop table mc3p;
@@ -3544,11 +3573,12 @@ select * from boolp where a = (select value from boolvalues where value);
      ->  Seq Scan on boolvalues (actual rows=1.00 loops=1)
            Filter: value
            Rows Removed by Filter: 1
+           Prefetch: avg=1.000 max=1 capacity=94
    ->  Seq Scan on boolp_f boolp_1 (never executed)
          Filter: (a = (InitPlan expr_1).col1)
    ->  Seq Scan on boolp_t boolp_2 (actual rows=0.00 loops=1)
          Filter: (a = (InitPlan expr_1).col1)
-(9 rows)
+(10 rows)
 
 explain (analyze, costs off, summary off, timing off, buffers off)
 select * from boolp where a = (select value from boolvalues where not value);
@@ -3559,11 +3589,12 @@ select * from boolp where a = (select value from boolvalues where not value);
      ->  Seq Scan on boolvalues (actual rows=1.00 loops=1)
            Filter: (NOT value)
            Rows Removed by Filter: 1
+           Prefetch: avg=1.000 max=1 capacity=94
    ->  Seq Scan on boolp_f boolp_1 (actual rows=0.00 loops=1)
          Filter: (a = (InitPlan expr_1).col1)
    ->  Seq Scan on boolp_t boolp_2 (never executed)
          Filter: (a = (InitPlan expr_1).col1)
-(9 rows)
+(10 rows)
 
 drop table boolp;
 --
diff --git a/src/test/regress/expected/select_parallel.out b/src/test/regress/expected/select_parallel.out
index 933921d1860..bfaf10a2906 100644
--- a/src/test/regress/expected/select_parallel.out
+++ b/src/test/regress/expected/select_parallel.out
@@ -580,7 +580,7 @@ select count(*) from bmscantest where a>1;
 -- test accumulation of stats for parallel nodes
 reset enable_seqscan;
 alter table tenk2 set (parallel_workers = 0);
-explain (analyze, timing off, summary off, costs off, buffers off)
+explain (analyze, timing off, summary off, costs off, buffers off, io off)
    select count(*) from tenk1, tenk2 where tenk1.hundred > 1
         and tenk2.thousand=0;
                                  QUERY PLAN                                  
@@ -606,7 +606,7 @@ $$
 declare ln text;
 begin
     for ln in
-        explain (analyze, timing off, summary off, costs off, buffers off)
+        explain (analyze, timing off, summary off, costs off, buffers off, io off)
           select * from
           (select ten from tenk1 where ten < 100 order by ten) ss
           right join (values (1),(2),(3)) v(x) on true
@@ -1170,7 +1170,7 @@ explain (costs off)
 -- to increase the parallel query test coverage
 SAVEPOINT settings;
 SET LOCAL debug_parallel_query = 1;
-EXPLAIN (analyze, timing off, summary off, costs off, buffers off) SELECT * FROM tenk1;
+EXPLAIN (analyze, timing off, summary off, costs off, buffers off, io off) SELECT * FROM tenk1;
                            QUERY PLAN                           
 ----------------------------------------------------------------
  Gather (actual rows=10000.00 loops=1)
diff --git a/src/test/regress/expected/subselect.out b/src/test/regress/expected/subselect.out
index 200236a0a69..0a1de6d7259 100644
--- a/src/test/regress/expected/subselect.out
+++ b/src/test/regress/expected/subselect.out
@@ -2051,7 +2051,7 @@ $$
 declare ln text;
 begin
     for ln in
-        explain (analyze, summary off, timing off, costs off, buffers off)
+        explain (analyze, summary off, timing off, costs off, buffers off, io off)
         select * from (select pk,c2 from sq_limit order by c1,pk) as x limit 3
     loop
         ln := regexp_replace(ln, 'Memory: \S*',  'Memory: xxx');
diff --git a/src/test/regress/sql/explain.sql b/src/test/regress/sql/explain.sql
index ebdab42604b..e9a3c2caf91 100644
--- a/src/test/regress/sql/explain.sql
+++ b/src/test/regress/sql/explain.sql
@@ -25,6 +25,10 @@ begin
         -- Ignore text-mode buffers output because it varies depending
         -- on the system state
         CONTINUE WHEN (ln ~ ' +Buffers: .*');
+        -- Ignore text-mode prefetch and I/O output because it varies
+        -- depending on the system state
+        CONTINUE WHEN (ln ~ ' +Prefetch: .*');
+        CONTINUE WHEN (ln ~ ' +I/O: .*');
         -- Ignore text-mode "Planning:" line because whether it's output
         -- varies depending on the system state
         CONTINUE WHEN (ln = 'Planning:');
@@ -63,11 +67,11 @@ set track_io_timing = off;
 
 explain (costs off) select 1 as a, 2 as b having false;
 select explain_filter('explain select * from int8_tbl i8');
-select explain_filter('explain (analyze, buffers off) select * from int8_tbl i8');
-select explain_filter('explain (analyze, buffers off, verbose) select * from int8_tbl i8');
+select explain_filter('explain (analyze, buffers off, io off) select * from int8_tbl i8');
+select explain_filter('explain (analyze, buffers off, io off, verbose) select * from int8_tbl i8');
 select explain_filter('explain (analyze, buffers, format text) select * from int8_tbl i8');
-select explain_filter('explain (analyze, buffers, format xml) select * from int8_tbl i8');
-select explain_filter('explain (analyze, serialize, buffers, format yaml) select * from int8_tbl i8');
+select explain_filter('explain (analyze, buffers, io off, format xml) select * from int8_tbl i8');
+select explain_filter('explain (analyze, serialize, buffers, io off, format yaml) select * from int8_tbl i8');
 select explain_filter('explain (buffers, format text) select * from int8_tbl i8');
 select explain_filter('explain (buffers, format json) select * from int8_tbl i8');
 
@@ -102,7 +106,7 @@ select explain_filter('explain (analyze, generic_plan) select unique1 from tenk1
 
 -- MEMORY option
 select explain_filter('explain (memory) select * from int8_tbl i8');
-select explain_filter('explain (memory, analyze, buffers off) select * from int8_tbl i8');
+select explain_filter('explain (memory, analyze, buffers off, io off) select * from int8_tbl i8');
 select explain_filter('explain (memory, summary, format yaml) select * from int8_tbl i8');
 select explain_filter('explain (memory, analyze, format json) select * from int8_tbl i8');
 prepare int8_query as select * from int8_tbl i8;
@@ -174,17 +178,17 @@ select explain_filter('explain (verbose) declare test_cur cursor for select * fr
 select explain_filter('explain (verbose) create table test_ctas as select 1');
 
 -- Test SERIALIZE option
-select explain_filter('explain (analyze,buffers off,serialize) select * from int8_tbl i8');
+select explain_filter('explain (analyze,buffers off,io off,serialize) select * from int8_tbl i8');
 select explain_filter('explain (analyze,serialize text,buffers,timing off) select * from int8_tbl i8');
 select explain_filter('explain (analyze,serialize binary,buffers,timing) select * from int8_tbl i8');
 -- this tests an edge case where we have no data to return
-select explain_filter('explain (analyze,buffers off,serialize) create temp table explain_temp as select * from int8_tbl i8');
+select explain_filter('explain (analyze,buffers off,io off,serialize) create temp table explain_temp as select * from int8_tbl i8');
 
 -- Test tuplestore storage usage in Window aggregate (memory case)
-select explain_filter('explain (analyze,buffers off,costs off) select sum(n) over() from generate_series(1,10) a(n)');
+select explain_filter('explain (analyze,buffers off,io off,costs off) select sum(n) over() from generate_series(1,10) a(n)');
 -- Test tuplestore storage usage in Window aggregate (disk case)
 set work_mem to 64;
-select explain_filter('explain (analyze,buffers off,costs off) select sum(n) over() from generate_series(1,2500) a(n)');
+select explain_filter('explain (analyze,buffers off,io off,costs off) select sum(n) over() from generate_series(1,2500) a(n)');
 -- Test tuplestore storage usage in Window aggregate (memory and disk case, final result is disk)
-select explain_filter('explain (analyze,buffers off,costs off) select sum(n) over(partition by m) from (SELECT n < 3 as m, n from generate_series(1,2500) a(n))');
+select explain_filter('explain (analyze,buffers off,io off,costs off) select sum(n) over(partition by m) from (SELECT n < 3 as m, n from generate_series(1,2500) a(n))');
 reset work_mem;
diff --git a/src/test/regress/sql/incremental_sort.sql b/src/test/regress/sql/incremental_sort.sql
index bbe658a7588..1c8036faade 100644
--- a/src/test/regress/sql/incremental_sort.sql
+++ b/src/test/regress/sql/incremental_sort.sql
@@ -21,7 +21,7 @@ declare
   line text;
 begin
   for line in
-    execute 'explain (analyze, costs off, summary off, timing off, buffers off) ' || query
+    execute 'explain (analyze, costs off, summary off, timing off, buffers off, io off) ' || query
   loop
     out_line := regexp_replace(line, '\d+kB', 'NNkB', 'g');
     return next;
@@ -38,7 +38,7 @@ declare
   element jsonb;
   matching_nodes jsonb := '[]'::jsonb;
 begin
-  execute 'explain (analyze, costs off, summary off, timing off, buffers off, format ''json'') ' || query into strict elements;
+  execute 'explain (analyze, costs off, summary off, timing off, buffers off, io off, format ''json'') ' || query into strict elements;
   while jsonb_array_length(elements) > 0 loop
     element := elements->0;
     elements := elements - 0;
diff --git a/src/test/regress/sql/memoize.sql b/src/test/regress/sql/memoize.sql
index 8d1cdd6990c..d1f80e18b41 100644
--- a/src/test/regress/sql/memoize.sql
+++ b/src/test/regress/sql/memoize.sql
@@ -11,7 +11,7 @@ declare
     ln text;
 begin
     for ln in
-        execute format('explain (analyze, costs off, summary off, timing off, buffers off) %s',
+        execute format('explain (analyze, costs off, summary off, timing off, buffers off, io off) %s',
             query)
     loop
         if hide_hitmiss = true then
diff --git a/src/test/regress/sql/merge.sql b/src/test/regress/sql/merge.sql
index 2660b19f238..c82e194078e 100644
--- a/src/test/regress/sql/merge.sql
+++ b/src/test/regress/sql/merge.sql
@@ -1074,7 +1074,7 @@ $$
 DECLARE ln text;
 BEGIN
     FOR ln IN
-        EXECUTE 'explain (analyze, timing off, summary off, costs off, buffers off) ' ||
+        EXECUTE 'explain (analyze, timing off, summary off, costs off, buffers off, io off) ' ||
 		  query
     LOOP
         ln := regexp_replace(ln, '(Memory( Usage)?|Buckets|Batches): \S*',  '\1: xxx', 'g');
diff --git a/src/test/regress/sql/partition_prune.sql b/src/test/regress/sql/partition_prune.sql
index d93c0c03bab..212de0e6285 100644
--- a/src/test/regress/sql/partition_prune.sql
+++ b/src/test/regress/sql/partition_prune.sql
@@ -12,7 +12,7 @@ declare
     ln text;
 begin
     for ln in
-        execute format('explain (analyze, costs off, summary off, timing off, buffers off) %s',
+        execute format('explain (analyze, costs off, summary off, timing off, buffers off, io off) %s',
             query)
     loop
         ln := regexp_replace(ln, 'Maximum Storage: \d+', 'Maximum Storage: N');
diff --git a/src/test/regress/sql/select_parallel.sql b/src/test/regress/sql/select_parallel.sql
index 71a75bc86ea..56e1ceac492 100644
--- a/src/test/regress/sql/select_parallel.sql
+++ b/src/test/regress/sql/select_parallel.sql
@@ -230,7 +230,7 @@ select count(*) from bmscantest where a>1;
 -- test accumulation of stats for parallel nodes
 reset enable_seqscan;
 alter table tenk2 set (parallel_workers = 0);
-explain (analyze, timing off, summary off, costs off, buffers off)
+explain (analyze, timing off, summary off, costs off, buffers off, io off)
    select count(*) from tenk1, tenk2 where tenk1.hundred > 1
         and tenk2.thousand=0;
 alter table tenk2 reset (parallel_workers);
@@ -242,7 +242,7 @@ $$
 declare ln text;
 begin
     for ln in
-        explain (analyze, timing off, summary off, costs off, buffers off)
+        explain (analyze, timing off, summary off, costs off, buffers off, io off)
           select * from
           (select ten from tenk1 where ten < 100 order by ten) ss
           right join (values (1),(2),(3)) v(x) on true
@@ -450,7 +450,7 @@ explain (costs off)
 -- to increase the parallel query test coverage
 SAVEPOINT settings;
 SET LOCAL debug_parallel_query = 1;
-EXPLAIN (analyze, timing off, summary off, costs off, buffers off) SELECT * FROM tenk1;
+EXPLAIN (analyze, timing off, summary off, costs off, buffers off, io off) SELECT * FROM tenk1;
 ROLLBACK TO SAVEPOINT settings;
 
 -- provoke error in worker
diff --git a/src/test/regress/sql/subselect.sql b/src/test/regress/sql/subselect.sql
index 4cd016f4ac3..3e930d8b56d 100644
--- a/src/test/regress/sql/subselect.sql
+++ b/src/test/regress/sql/subselect.sql
@@ -1016,7 +1016,7 @@ $$
 declare ln text;
 begin
     for ln in
-        explain (analyze, summary off, timing off, costs off, buffers off)
+        explain (analyze, summary off, timing off, costs off, buffers off, io off)
         select * from (select pk,c2 from sq_limit order by c1,pk) as x limit 3
     loop
         ln := regexp_replace(ln, 'Memory: \S*',  'Memory: xxx');
-- 
2.53.0