[PATCH] pg_stat_toast

From aa89c5183d4a9ab99b6a07a456ec12ed3934b930 Mon Sep 17 00:00:00 2001
From: "Gunnar \"Nick\" Bluth" <gunnar.bluth@pro-open.de>
Date: Mon, 13 Dec 2021 14:14:40 +0100
Subject: [PATCH] * make pgstat_track_toast a "real" GUC * reduce size of
 initial hash per backend to 32 * disable DEBUG2 elog() calls

---
 pg_stat_toast.sql                       |  19 ++
 src/backend/access/table/toast_helper.c |  19 ++
 src/backend/postmaster/pgstat.c         | 311 +++++++++++++++++++++++-
 src/backend/utils/adt/pgstatfuncs.c     |  60 +++++
 src/backend/utils/misc/guc.c            |   9 +
 src/include/catalog/pg_proc.dat         |  21 ++
 src/include/pgstat.h                    | 109 +++++++++
 7 files changed, 542 insertions(+), 6 deletions(-)
 create mode 100644 pg_stat_toast.sql

diff --git a/pg_stat_toast.sql b/pg_stat_toast.sql
new file mode 100644
index 0000000000..1c653254ab
--- /dev/null
+++ b/pg_stat_toast.sql
@@ -0,0 +1,19 @@
+-- This creates a useable view, but the offset of 1 is annoying.
+-- That "-1" is probably better done in the helper functions...
+
+CREATE OR REPLACE VIEW pg_stat_toast AS
+ SELECT 
+    n.nspname AS schemaname,
+    a.attrelid AS reloid,
+    a.attnum AS attnum,
+    c.relname AS relname,
+    a.attname AS attname,
+    pg_stat_get_toast_externalizations(a.attrelid,a.attnum -1) AS externalizations,
+    pg_stat_get_toast_compressions(a.attrelid,a.attnum -1) AS compressions,
+    pg_stat_get_toast_compressionsuccesses(a.attrelid,a.attnum -1) AS compressionsuccesses,
+    pg_stat_get_toast_compressedsizesum(a.attrelid,a.attnum -1) AS compressionsizesum,
+    pg_stat_get_toast_originalsizesum(a.attrelid,a.attnum -1) AS originalsizesum
+   FROM pg_attribute a
+   JOIN pg_class c ON c.oid = a.attrelid
+   LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
+  WHERE pg_stat_get_toast_externalizations(a.attrelid,a.attnum -1) IS NOT NULL;
diff --git a/src/backend/access/table/toast_helper.c b/src/backend/access/table/toast_helper.c
index 013236b73d..49545885d5 100644
--- a/src/backend/access/table/toast_helper.c
+++ b/src/backend/access/table/toast_helper.c
@@ -19,6 +19,7 @@
 #include "access/toast_helper.h"
 #include "access/toast_internals.h"
 #include "catalog/pg_type_d.h"
+#include "pgstat.h"
 
 
 /*
@@ -239,6 +240,12 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 			pfree(DatumGetPointer(*value));
 		*value = new_value;
 		attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
+		pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							attr->tai_size,
+							VARSIZE(DatumGetPointer(*value)),
+							0);
 		attr->tai_size = VARSIZE(DatumGetPointer(*value));
 		ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
 	}
@@ -246,6 +253,12 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 	{
 		/* incompressible, ignore on subsequent compression passes */
 		attr->tai_colflags |= TOASTCOL_INCOMPRESSIBLE;
+		pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							0,
+							0,
+							0);
 	}
 }
 
@@ -266,6 +279,12 @@ toast_tuple_externalize(ToastTupleContext *ttc, int attribute, int options)
 		pfree(DatumGetPointer(old_value));
 	attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
 	ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
+	pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							true,
+							false,
+							0,
+							0,
+							0);
 }
 
 /*
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 7264d2c727..4176a41418 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -106,6 +106,7 @@
 #define PGSTAT_DB_HASH_SIZE		16
 #define PGSTAT_TAB_HASH_SIZE	512
 #define PGSTAT_FUNCTION_HASH_SIZE	512
+#define PGSTAT_TOAST_HASH_SIZE	32
 #define PGSTAT_SUBWORKER_HASH_SIZE	32
 #define PGSTAT_REPLSLOT_HASH_SIZE	32
 
@@ -116,6 +117,7 @@
  */
 bool		pgstat_track_counts = false;
 int			pgstat_track_functions = TRACK_FUNC_OFF;
+bool		pgstat_track_toast = true;
 
 /* ----------
  * Built from GUC parameter
@@ -228,6 +230,19 @@ static HTAB *pgStatFunctions = NULL;
  */
 static bool have_function_stats = false;
 
+/*
+ * Backends store per-toast-column info that's waiting to be sent to the collector
+ * in this hash table (indexed by column's PgStat_BackendAttrIdentifier).
+ */
+static HTAB *pgStatToastActions = NULL;
+
+
+/*
+ * Indicates if backend has some toast stats that it hasn't yet
+ * sent to the collector.
+ */
+static bool have_toast_stats = false;
+
 /*
  * Tuple insertion/deletion counts for an open transaction can't be propagated
  * into PgStat_TableStatus counters until we know if it is going to commit
@@ -328,7 +343,7 @@ static PgStat_StatSubWorkerEntry *pgstat_get_subworker_entry(PgStat_StatDBEntry
 static void pgstat_write_statsfiles(bool permanent, bool allDbs);
 static void pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent);
 static HTAB *pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep);
-static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 									 HTAB *subworkerhash, bool permanent);
 static void backend_read_statsfile(void);
 
@@ -340,6 +355,7 @@ static void pgstat_reset_replslot(PgStat_StatReplSlotEntry *slotstats, Timestamp
 
 static void pgstat_send_tabstat(PgStat_MsgTabstat *tsmsg, TimestampTz now);
 static void pgstat_send_funcstats(void);
+static void pgstat_send_toaststats(void);
 static void pgstat_send_slru(void);
 static void pgstat_send_subscription_purge(PgStat_MsgSubscriptionPurge *msg);
 static HTAB *pgstat_collect_oids(Oid catalogid, AttrNumber anum_oid);
@@ -373,6 +389,7 @@ static void pgstat_recv_wal(PgStat_MsgWal *msg, int len);
 static void pgstat_recv_slru(PgStat_MsgSLRU *msg, int len);
 static void pgstat_recv_funcstat(PgStat_MsgFuncstat *msg, int len);
 static void pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len);
+static void pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len);
 static void pgstat_recv_recoveryconflict(PgStat_MsgRecoveryConflict *msg, int len);
 static void pgstat_recv_deadlock(PgStat_MsgDeadlock *msg, int len);
 static void pgstat_recv_checksum_failure(PgStat_MsgChecksumFailure *msg, int len);
@@ -891,7 +908,7 @@ pgstat_report_stat(bool disconnect)
 		pgStatXactCommit == 0 && pgStatXactRollback == 0 &&
 		pgWalUsage.wal_records == prevWalUsage.wal_records &&
 		WalStats.m_wal_write == 0 && WalStats.m_wal_sync == 0 &&
-		!have_function_stats && !disconnect)
+		!have_function_stats && !have_toast_stats && !disconnect)
 		return;
 
 	/*
@@ -983,6 +1000,9 @@ pgstat_report_stat(bool disconnect)
 	/* Now, send function statistics */
 	pgstat_send_funcstats();
 
+	/* Now, send TOAST statistics */
+	pgstat_send_toaststats();
+
 	/* Send WAL statistics */
 	pgstat_send_wal(true);
 
@@ -1116,6 +1136,64 @@ pgstat_send_funcstats(void)
 	have_function_stats = false;
 }
 
+/*
+ * Subroutine for pgstat_report_stat: populate and send a toast stat message
+ */
+static void
+pgstat_send_toaststats(void)
+{
+	/* we assume this inits to all zeroes: */
+	static const PgStat_ToastCounts all_zeroes;
+
+	PgStat_MsgToaststat msg;
+	PgStat_BackendToastEntry *entry;
+	HASH_SEQ_STATUS tstat;
+
+	if (pgStatToastActions == NULL)
+		return;
+
+	pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_TOASTSTAT);
+	msg.m_databaseid = MyDatabaseId;
+	msg.m_nentries = 0;
+
+	hash_seq_init(&tstat, pgStatToastActions);
+	while ((entry = (PgStat_BackendToastEntry *) hash_seq_search(&tstat)) != NULL)
+	{
+		PgStat_ToastEntry *m_ent;
+
+		/* Skip it if no counts accumulated since last time */
+		if (memcmp(&entry->t_counts, &all_zeroes,
+				   sizeof(PgStat_ToastCounts)) == 0)
+			continue;
+
+		/* need to convert format of time accumulators */
+		m_ent = &msg.m_entry[msg.m_nentries];
+		m_ent->attr = entry->attr;
+		m_ent->t_numexternalized = entry->t_counts.t_numexternalized;
+		m_ent->t_numcompressed = entry->t_counts.t_numcompressed;
+		m_ent->t_numcompressionsuccess = entry->t_counts.t_numcompressionsuccess;
+		m_ent->t_size_orig = entry->t_counts.t_size_orig;
+		m_ent->t_size_compressed = entry->t_counts.t_size_compressed;
+		m_ent->t_comp_time = INSTR_TIME_GET_MICROSEC(entry->t_counts.t_comp_time);
+
+		if (++msg.m_nentries >= PGSTAT_NUM_TOASTENTRIES)
+		{
+			pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+						msg.m_nentries * sizeof(PgStat_ToastEntry));
+			msg.m_nentries = 0;
+		}
+
+		/* reset the entry's counts */
+		MemSet(&entry->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	if (msg.m_nentries > 0)
+		pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+					msg.m_nentries * sizeof(PgStat_ToastEntry));
+
+	have_toast_stats = false;
+}
+
 
 /* ----------
  * pgstat_vacuum_stat() -
@@ -2151,6 +2229,76 @@ pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu, bool finalize)
 	have_function_stats = true;
 }
 
+/*
+ * Report TOAST activity
+ * Called by toast_helper functions.
+ */
+void
+pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							int32 time_spent)
+{
+	PgStat_BackendAttrIdentifier toastattr = { relid, attr };
+	PgStat_BackendToastEntry *htabent;
+	bool		found;
+
+	if (pgStatSock == PGINVALID_SOCKET || !pgstat_track_toast)
+		return;
+
+	if (!pgStatToastActions)
+	{
+		/* First time through - initialize toast stat table */
+		HASHCTL		hash_ctl;
+
+		hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+		hash_ctl.entrysize = sizeof(PgStat_BackendToastEntry);
+		pgStatToastActions = hash_create("TOAST stat entries",
+									  PGSTAT_TOAST_HASH_SIZE,
+									  &hash_ctl,
+									  HASH_ELEM | HASH_BLOBS);
+	}
+
+	/* Get the stats entry for this TOAST attribute, create if necessary */
+	htabent = hash_search(pgStatToastActions, &toastattr,
+						  HASH_ENTER, &found);
+	if (!found)
+	{
+		/* elog(DEBUG2, "No toast entry found for attr %u of relation %u", attr, relid); */
+		MemSet(&htabent->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	/* update counters */
+	if (externalized)
+	{
+		htabent->t_counts.t_numexternalized++;
+		/* elog(DEBUG2, "Externalized counter raised for OID %u, attr %u, now %li", relid,attr, htabent->t_counts.t_numexternalized); */
+	}
+	if (compressed)
+	{
+		htabent->t_counts.t_numcompressed++;
+		/* elog(DEBUG2, "Compressed counter raised for OID %u, attr %u, now %li", relid,attr, htabent->t_counts.t_numcompressed); */
+		if (new_size)
+		{
+			htabent->t_counts.t_size_orig+=old_size;
+			/* elog(DEBUG2, "Old size %u added for OID %u, attr %u, now %li",old_size,relid,attr,  htabent->t_counts.t_size_orig); */
+			if (new_size)
+			{
+				htabent->t_counts.t_numcompressionsuccess++;
+				/* elog(DEBUG2, "Compressed success counter raised for OID %u, attr %u, now %li",relid,attr, htabent->t_counts.t_numcompressionsuccess); */
+				htabent->t_counts.t_size_compressed+=new_size;
+				/* elog(DEBUG2, "New size %u added for OID %u, attr %u, now %li",new_size,relid,attr, htabent->t_counts.t_size_compressed); */
+			}
+		}
+		/* TODO: record times */
+	}	
+	
+	/* indicate that we have something to send */
+	have_toast_stats = true;
+}
+
 
 /* ----------
  * pgstat_initstats() -
@@ -3028,6 +3176,35 @@ pgstat_fetch_stat_subworker_entry(Oid subid, Oid subrelid)
 	return wentry;
 }
 
+/* ----------
+ * pgstat_fetch_stat_toastentry() -
+ *
+ *	Support function for the SQL-callable pgstat* functions. Returns
+ *	the collected statistics for one TOAST attribute or NULL.
+ * ----------
+ */
+PgStat_StatToastEntry *
+pgstat_fetch_stat_toastentry(Oid rel_id, int attr)
+{
+	PgStat_StatDBEntry *dbentry;
+	PgStat_BackendAttrIdentifier toast_id = { rel_id, attr };
+	PgStat_StatToastEntry *toastentry = NULL;
+
+	/* load the stats file if needed */
+	backend_read_statsfile();
+
+	/* Lookup our database, then find the requested TOAST activity stats.  */
+	dbentry = pgstat_fetch_stat_dbentry(MyDatabaseId);
+	if (dbentry != NULL && dbentry->toastactivity != NULL)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &toast_id,
+														 HASH_FIND, NULL);
+	}
+
+	return toastentry;
+}
+
 /*
  * ---------
  * pgstat_fetch_stat_archiver() -
@@ -3708,6 +3885,10 @@ PgstatCollectorMain(int argc, char *argv[])
 					pgstat_recv_funcpurge(&msg.msg_funcpurge, len);
 					break;
 
+				case PGSTAT_MTYPE_TOASTSTAT:
+					pgstat_recv_toaststat(&msg.msg_toaststat, len);
+					break;
+				
 				case PGSTAT_MTYPE_RECOVERYCONFLICT:
 					pgstat_recv_recoveryconflict(&msg.msg_recoveryconflict,
 												 len);
@@ -3852,6 +4033,14 @@ reset_dbentry_counters(PgStat_StatDBEntry *dbentry)
 									  PGSTAT_SUBWORKER_HASH_SIZE,
 									  &hash_ctl,
 									  HASH_ELEM | HASH_BLOBS);
+
+	hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+	hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+	dbentry->toastactivity = hash_create("Per-database TOAST",
+									 PGSTAT_TOAST_HASH_SIZE,
+									 &hash_ctl,
+									 HASH_ELEM | HASH_BLOBS);
+
 }
 
 /*
@@ -4059,8 +4248,8 @@ pgstat_write_statsfiles(bool permanent, bool allDbs)
 	while ((dbentry = (PgStat_StatDBEntry *) hash_seq_search(&hstat)) != NULL)
 	{
 		/*
-		 * Write out the table, function, and subscription-worker stats for
-		 * this DB into the appropriate per-DB stat file, if required.
+		 * Write out the table, function, TOAST and subscription-worker stats for this DB into the
+		 * appropriate per-DB stat file, if required.
 		 */
 		if (allDbs || pgstat_db_requested(dbentry->databaseid))
 		{
@@ -4175,9 +4364,11 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 	HASH_SEQ_STATUS tstat;
 	HASH_SEQ_STATUS fstat;
 	HASH_SEQ_STATUS sstat;
+	HASH_SEQ_STATUS ostat;
 	PgStat_StatTabEntry *tabentry;
 	PgStat_StatFuncEntry *funcentry;
 	PgStat_StatSubWorkerEntry *subwentry;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpout;
 	int32		format_id;
 	Oid			dbid = dbentry->databaseid;
@@ -4243,6 +4434,17 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 		(void) rc;				/* we'll check for error with ferror */
 	}
 
+	/*
+	 * Walk through the database's TOAST stats table.
+	 */
+	hash_seq_init(&ostat, dbentry->toastactivity);
+	while ((toastentry = (PgStat_StatToastEntry *) hash_seq_search(&ostat)) != NULL)
+	{
+		fputc('O', fpout);
+		rc = fwrite(toastentry, sizeof(PgStat_StatToastEntry), 1, fpout);
+		(void) rc;				/* we'll check for error with ferror */
+	}
+
 	/*
 	 * No more output to be done. Close the temp file and replace the old
 	 * pgstat.stat with it.  The ferror() check replaces testing for error
@@ -4483,6 +4685,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 				dbentry->tables = NULL;
 				dbentry->functions = NULL;
 				dbentry->subworkers = NULL;
+				dbentry->toastactivity = NULL;
 
 				/*
 				 * In the collector, disregard the timestamp we read from the
@@ -4528,6 +4731,14 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 												  &hash_ctl,
 												  HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
 
+				hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+				hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+				hash_ctl.hcxt = pgStatLocalContext;
+				dbentry->toastactivity = hash_create("Per-database toast information",
+												 PGSTAT_TOAST_HASH_SIZE,
+												 &hash_ctl,
+												 HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
+
 				/*
 				 * If requested, read the data from the database-specific
 				 * file.  Otherwise we just leave the hashtables empty.
@@ -4536,6 +4747,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 					pgstat_read_db_statsfile(dbentry->databaseid,
 											 dbentry->tables,
 											 dbentry->functions,
+											 dbentry->toastactivity,
 											 dbentry->subworkers,
 											 permanent);
 
@@ -4620,7 +4832,7 @@ done:
  * ----------
  */
 static void
-pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 						 HTAB *subworkerhash, bool permanent)
 {
 	PgStat_StatTabEntry *tabentry;
@@ -4629,6 +4841,8 @@ pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
 	PgStat_StatFuncEntry *funcentry;
 	PgStat_StatSubWorkerEntry subwbuf;
 	PgStat_StatSubWorkerEntry *subwentry;
+	PgStat_StatToastEntry toastbuf;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpin;
 	int32		format_id;
 	bool		found;
@@ -4777,6 +4991,32 @@ pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
 				memcpy(subwentry, &subwbuf, sizeof(subwbuf));
 				break;
 
+
+				/*
+				 * 'O'	A PgStat_StatToastEntry follows (tOast)
+				 */
+			case 'O':
+				if (fread(&toastbuf, 1, sizeof(PgStat_StatToastEntry),
+						  fpin) != sizeof(PgStat_StatToastEntry))
+				{
+					ereport(pgStatRunningInCollector ? LOG : WARNING,
+							(errmsg("corrupted statistics file \"%s\"",
+									statfile)));
+					goto done;
+				}
+
+				/*
+				 * Skip if TOAST data not wanted.
+				 */
+				if (toasthash == NULL)
+					break;
+
+				toastentry = (PgStat_StatToastEntry *) hash_search(toasthash,
+																 (void *) &toastbuf.t_id,
+																 HASH_ENTER, &found);
+				memcpy(toastentry, &toastbuf, sizeof(toastbuf));
+				break;
+
 				/*
 				 * 'E'	The EOF marker of a complete stats file.
 				 */
@@ -5452,6 +5692,8 @@ pgstat_recv_dropdb(PgStat_MsgDropdb *msg, int len)
 			hash_destroy(dbentry->functions);
 		if (dbentry->subworkers != NULL)
 			hash_destroy(dbentry->subworkers);
+		if (dbentry->toastactivity != NULL)
+			hash_destroy(dbentry->toastactivity);
 
 		if (hash_search(pgStatDBHash,
 						(void *) &dbid,
@@ -5491,10 +5733,12 @@ pgstat_recv_resetcounter(PgStat_MsgResetcounter *msg, int len)
 		hash_destroy(dbentry->functions);
 	if (dbentry->subworkers != NULL)
 		hash_destroy(dbentry->subworkers);
-
+	if (dbentry->toastactivity != NULL)
+		hash_destroy(dbentry->toastactivity);
 	dbentry->tables = NULL;
 	dbentry->functions = NULL;
 	dbentry->subworkers = NULL;
+	dbentry->toastactivity = NULL;
 
 	/*
 	 * Reset database-level stats, too.  This creates empty hash tables for
@@ -6152,6 +6396,61 @@ pgstat_recv_subscription_purge(PgStat_MsgSubscriptionPurge *msg, int len)
 	}
 }
 
+/* ----------
+ * pgstat_recv_toaststat() -
+ *
+ *	Count what the backend has done.
+ * ----------
+ */
+static void
+pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len)
+{
+	PgStat_ToastEntry *toastmsg = &(msg->m_entry[0]);
+	PgStat_StatDBEntry *dbentry;
+	PgStat_StatToastEntry *toastentry;
+	int			i;
+	bool		found;
+
+	elog(DEBUG2, "Received TOAST statistics...");
+	dbentry = pgstat_get_db_entry(msg->m_databaseid, true);
+
+	/*
+	 * Process all TOAST entries in the message.
+	 */
+	for (i = 0; i < msg->m_nentries; i++, toastmsg++)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &(toastmsg->attr),
+														 HASH_ENTER, &found);
+
+		if (!found)
+		{
+			/*
+			 * If it's a new entry, initialize counters to the values
+			 * we just got.
+			 */
+			elog(DEBUG2, "First time I see this toastentry");
+			toastentry->t_numexternalized = toastmsg->t_numexternalized;
+			toastentry->t_numcompressed = toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess = toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_compressed = toastmsg->t_size_compressed;
+			toastentry->t_size_orig = toastmsg->t_size_orig;
+		}
+		else
+		{
+			/*
+			 * Otherwise add the values to the existing entry.
+			 */
+			elog(DEBUG2, "Found this toastentry, updating");
+			toastentry->t_numexternalized += toastmsg->t_numexternalized;
+			toastentry->t_numcompressed += toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess += toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_compressed += toastmsg->t_size_compressed;
+			toastentry->t_size_orig += toastmsg->t_size_orig;
+		}
+	}
+}
+
 /* ----------
  * pgstat_recv_subworker_error() -
  *
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index f529c1561a..bbdcbe14ee 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -410,6 +410,66 @@ pg_stat_get_function_self_time(PG_FUNCTION_ARGS)
 	PG_RETURN_FLOAT8(((double) funcentry->f_self_time) / 1000.0);
 }
 
+Datum
+pg_stat_get_toast_externalizations(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numexternalized);
+}
+
+Datum
+pg_stat_get_toast_compressions(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressed);
+}
+
+Datum
+pg_stat_get_toast_compressionsuccesses(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressionsuccess);
+}
+
+Datum
+pg_stat_get_toast_originalsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_orig);
+}
+
+Datum
+pg_stat_get_toast_compressedsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_compressed);
+}
+
 Datum
 pg_stat_get_backend_idset(PG_FUNCTION_ARGS)
 {
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index ee6a838b3a..8114b8841d 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -1540,6 +1540,15 @@ static struct config_bool ConfigureNamesBool[] =
 		true,
 		NULL, NULL, NULL
 	},
+	{
+		{"track_toast", PGC_SUSET, STATS_COLLECTOR,
+			gettext_noop("Collects statistics on TOAST activity."),
+			NULL
+		},
+		&pgstat_track_toast,
+		false,
+		NULL, NULL, NULL
+	},
 	{
 		{"track_io_timing", PGC_SUSET, STATS_COLLECTOR,
 			gettext_noop("Collects timing statistics for database I/O activity."),
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 79d787cd26..16ea25f433 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5686,6 +5686,27 @@
   proparallel => 'r', prorettype => 'float8', proargtypes => 'oid',
   prosrc => 'pg_stat_get_function_self_time' },
 
+{ oid => '9700', descr => 'statistics: number of TOAST externalizations',
+  proname => 'pg_stat_get_toast_externalizations', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_externalizations' },
+{ oid => '9701', descr => 'statistics: number of TOAST compressions',
+  proname => 'pg_stat_get_toast_compressions', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressions' },
+  { oid => '9702', descr => 'statistics: number of successful TOAST compressions',
+  proname => 'pg_stat_get_toast_compressionsuccesses', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressionsuccesses' },
+{ oid => '9703', descr => 'statistics: total original size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_originalsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_originalsizesum' },
+{ oid => '9704', descr => 'statistics: total compressed size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_compressedsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressedsizesum' },
+
 { oid => '3037',
   descr => 'statistics: number of scans done for table/index in current transaction',
   proname => 'pg_stat_get_xact_numscans', provolatile => 'v',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5b51b58e5a..81b410e612 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -82,10 +82,12 @@ typedef enum StatMsgType
 	PGSTAT_MTYPE_DEADLOCK,
 	PGSTAT_MTYPE_CHECKSUMFAILURE,
 	PGSTAT_MTYPE_REPLSLOT,
+	PGSTAT_MTYPE_CONNECTION,
 	PGSTAT_MTYPE_CONNECT,
 	PGSTAT_MTYPE_DISCONNECT,
 	PGSTAT_MTYPE_SUBSCRIPTIONPURGE,
 	PGSTAT_MTYPE_SUBWORKERERROR,
+	PGSTAT_MTYPE_TOASTSTAT,
 } StatMsgType;
 
 /* ----------
@@ -733,6 +735,80 @@ typedef struct PgStat_MsgDisconnect
 	SessionEndType m_cause;
 } PgStat_MsgDisconnect;
 
+/* ----------
+ * PgStat_BackendAttrIdentifier	Identifier for a single attribute/column (OID + attr)
+ * Used as a hashable identifier for (e.g.) TOAST columns
+ * ----------
+ */
+typedef struct PgStat_BackendAttrIdentifier
+{
+	Oid			relid;
+	int			attr;
+} PgStat_BackendAttrIdentifier;
+
+/* ----------
+ * PgStat_ToastCounts	The actual per-TOAST counts kept by a backend
+ *
+ * This struct should contain only actual event counters, because we memcmp
+ * it against zeroes to detect whether there are any counts to transmit.
+ *
+ * Note that the time counters are in instr_time format here.  We convert to
+ * microseconds in PgStat_Counter format when transmitting to the collector.
+ * ----------
+ */
+typedef struct PgStat_ToastCounts
+{
+	PgStat_Counter t_numexternalized;
+	PgStat_Counter t_numcompressed;
+	PgStat_Counter t_numcompressionsuccess;
+	uint64		   t_size_orig;
+	uint64		   t_size_compressed;
+	instr_time     t_comp_time;
+} PgStat_ToastCounts;
+
+/* ----------
+ * PgStat_BackendToastEntry	Entry in backend's per-toast-attr hash table
+ * ----------
+ */
+typedef struct PgStat_BackendToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_ToastCounts 				t_counts;
+} PgStat_BackendToastEntry;
+
+/* ----------
+ * PgStat_ToastEntry			Per-TOAST-column info in a MsgFuncstat
+ * ----------
+ */
+typedef struct PgStat_ToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_Counter 					t_numexternalized;
+	PgStat_Counter 					t_numcompressed;
+	PgStat_Counter 					t_numcompressionsuccess;
+	uint64		   					t_size_orig;
+	uint64		   					t_size_compressed;
+	PgStat_Counter					t_comp_time;	/* time in microseconds */
+} PgStat_ToastEntry;
+
+/* ----------
+ * PgStat_MsgToaststat			Sent by the backend to report function
+ *								usage statistics.
+ * ----------
+ */
+#define PGSTAT_NUM_TOASTENTRIES	\
+	((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - sizeof(int))  \
+	 / sizeof(PgStat_ToastEntry))
+
+typedef struct PgStat_MsgToaststat
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+	int			m_nentries;
+	PgStat_ToastEntry m_entry[PGSTAT_NUM_TOASTENTRIES];
+} PgStat_MsgToaststat;
+
+
 /* ----------
  * PgStat_Msg					Union over all possible messages.
  * ----------
@@ -760,6 +836,7 @@ typedef union PgStat_Msg
 	PgStat_MsgSLRU msg_slru;
 	PgStat_MsgFuncstat msg_funcstat;
 	PgStat_MsgFuncpurge msg_funcpurge;
+	PgStat_MsgToaststat msg_toaststat;
 	PgStat_MsgRecoveryConflict msg_recoveryconflict;
 	PgStat_MsgDeadlock msg_deadlock;
 	PgStat_MsgTempFile msg_tempfile;
@@ -833,6 +910,7 @@ typedef struct PgStat_StatDBEntry
 	HTAB	   *tables;
 	HTAB	   *functions;
 	HTAB	   *subworkers;
+	HTAB	   *toastactivity;
 } PgStat_StatDBEntry;
 
 
@@ -1022,6 +1100,23 @@ typedef struct PgStat_StatSubWorkerEntry
 	char		last_error_message[PGSTAT_SUBWORKERERROR_MSGLEN];
 } PgStat_StatSubWorkerEntry;
 
+/* ----------
+ * PgStat_StatToastEntry			The collector's data per TOAST attribute
+ * ----------
+ */
+typedef struct PgStat_StatToastEntry
+{
+	PgStat_BackendAttrIdentifier t_id;
+	PgStat_Counter t_numexternalized;
+	PgStat_Counter t_numcompressed;
+	PgStat_Counter t_numcompressionsuccess;
+	uint64		   t_size_orig;
+	uint64		   t_size_compressed;
+
+	PgStat_Counter t_comp_time;	/* time in microseconds */
+} PgStat_StatToastEntry;
+
+
 /*
  * Working state needed to accumulate per-function-call timing statistics.
  */
@@ -1045,6 +1140,7 @@ typedef struct PgStat_FunctionCallUsage
  */
 extern PGDLLIMPORT bool pgstat_track_counts;
 extern PGDLLIMPORT int pgstat_track_functions;
+extern PGDLLIMPORT bool pgstat_track_toast;
 extern char *pgstat_stat_directory;
 extern char *pgstat_stat_tmpname;
 extern char *pgstat_stat_filename;
@@ -1196,12 +1292,22 @@ extern void pgstat_count_heap_delete(Relation rel);
 extern void pgstat_count_truncate(Relation rel);
 extern void pgstat_update_heap_dead_tuples(Relation rel, int delta);
 
+extern void pgstat_count_toast_insert(Relation rel, PgStat_Counter n);
+
 struct FunctionCallInfoBaseData;
 extern void pgstat_init_function_usage(struct FunctionCallInfoBaseData *fcinfo,
 									   PgStat_FunctionCallUsage *fcu);
 extern void pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu,
 									  bool finalize);
 
+extern void
+pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							int32 time_spent);
+
 extern void AtEOXact_PgStat(bool isCommit, bool parallel);
 extern void AtEOSubXact_PgStat(bool isCommit, int nestDepth);
 
@@ -1228,9 +1334,12 @@ extern PgStat_StatTabEntry *pgstat_fetch_stat_tabentry(Oid relid);
 extern PgStat_StatFuncEntry *pgstat_fetch_stat_funcentry(Oid funcid);
 extern PgStat_StatSubWorkerEntry *pgstat_fetch_stat_subworker_entry(Oid subid,
 																	Oid subrelid);
+extern PgStat_StatToastEntry *pgstat_fetch_stat_toastentry(Oid rel_id, int attr);
+extern PgStat_ArchiverStats *pgstat_fetch_stat_archiver(void);
 extern PgStat_ArchiverStats *pgstat_fetch_stat_archiver(void);
 extern PgStat_BgWriterStats *pgstat_fetch_stat_bgwriter(void);
 extern PgStat_CheckpointerStats *pgstat_fetch_stat_checkpointer(void);
+
 extern PgStat_GlobalStats *pgstat_fetch_global(void);
 extern PgStat_WalStats *pgstat_fetch_stat_wal(void);
 extern PgStat_SLRUStats *pgstat_fetch_slru(void);
-- 
2.32.0

From e4f6b8a9b398ff08f76e0c02ca7a1201062beb78 Mon Sep 17 00:00:00 2001
From: "Gunnar \"Nick\" Bluth" <gunnar.bluth@pro-open.de>
Date: Mon, 20 Dec 2021 14:09:36 +0100
Subject: [PATCH] pg_stat_toast v0.3


    * adds timing information to stats and view
    * adds system view
    * adds documentation
    * adds GUC parameter to postgresql.conf

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index afbb6c35e3..fa40befc16 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -7668,6 +7668,32 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv;
       </listitem>
      </varlistentry>
 
+     <varlistentry id="guc-track-toast" xreflabel="track_toast">
+      <term><varname>track_toast</varname> (<type>boolean</type>)
+      <indexterm>
+       <primary><varname>track_toast</varname> configuration parameter</primary>
+      </indexterm>
+      </term>
+      <listitem>
+       <para>
+        Enables tracking of <link linkend="storage-toast">TOAST</link> activities.
+        Compressions and externalizations are tracked.
+        The default is <literal>off</literal>.
+        Only superusers can change this setting.
+       </para>
+
+       <note>
+        <para>
+        Be aware that this feature, depending on the amount of TOASTable columns in
+        your databases, may significantly increase the size of the statistics files
+        and the workload of the statistics collector. It is recommended to only
+        temporarily activate this to assess the right compression and storage method
+        for (a) column(s).
+        </para>
+       </note>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="guc-stats-temp-directory" xreflabel="stats_temp_directory">
       <term><varname>stats_temp_directory</varname> (<type>string</type>)
       <indexterm>
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 62f2a3332b..32d7818096 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -610,6 +610,17 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
       yet included in <structname>pg_stat_user_functions</structname>).</entry>
      </row>
 
+     <row>
+      <entry><structname>pg_stat_toast</structname><indexterm><primary>pg_stat_toast</primary></indexterm></entry>
+      <entry>
+       One row for each column that has ever been TOASTed (compressed and/or externalized).
+       Showing the number of externalizations, compression attempts / successes, compressed and
+       uncompressed sizes etc.
+       <link linkend="monitoring-pg-stat-toast-view">
+       <structname>pg_stat_toast</structname></link> for details.
+      </entry>
+     </row>
+
      <row>
       <entry><structname>pg_stat_slru</structname><indexterm><primary>pg_stat_slru</primary></indexterm></entry>
       <entry>One row per SLRU, showing statistics of operations. See
@@ -4969,6 +4980,158 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
 
  </sect2>
 
+ <sect2 id="monitoring-pg-stat-toast-view">
+  <title><structname>pg_stat_toast</structname></title>
+
+  <indexterm>
+   <primary>pg_stat_toast</primary>
+  </indexterm>
+
+  <para>
+   The <structname>pg_stat_toast</structname> view will contain
+   one row for each column of variable size that has been TOASTed since 
+   the last statistics reset. The <xref linkend="guc-track-toast"/> parameter
+   controls whether TOAST activities are tracked or not.
+  </para>
+
+  <table id="pg-stat-toast-view" xreflabel="pg_stat_toast">
+   <title><structname>pg_stat_toast</structname> View</title>
+   <tgroup cols="1">
+    <thead>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       Column Type
+      </para>
+      <para>
+       Description
+      </para></entry>
+     </row>
+    </thead>
+
+    <tbody>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>schemaname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the schema the relation is in
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>reloid</structfield> <type>oid</type>
+      </para>
+      <para>
+       OID of the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>attnum</structfield> <type>int</type>
+      </para>
+      <para>
+       Attribute (column) number in the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>relname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>attname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the attribute (column)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>storagemethod</structfield> <type>char</type>
+      </para>
+      <para>
+       Storage method of the attribute
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>externalized</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times this attribute was externalized (pushed to TOAST relation)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressmethod</structfield> <type>char</type>
+      </para>
+      <para>
+       Compression method of the attribute (empty means default)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressattempts</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times this attribute was compressed
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compresssuccesses</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times the compression was successful (gained a size reduction)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressedsize</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total size of all compressed datums
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>originalsize</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total size of all compressed datums before compression
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>total_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Total time spent TOASTing this attribute, in microseconds.
+      </para></entry>
+     </row>
+
+    </tbody>
+   </tgroup>
+  </table>
+
+ </sect2>
+
  <sect2 id="monitoring-pg-stat-slru-view">
   <title><structname>pg_stat_slru</structname></title>
 
diff --git a/doc/src/sgml/storage.sgml b/doc/src/sgml/storage.sgml
index 7136bbe7a3..2a47922573 100644
--- a/doc/src/sgml/storage.sgml
+++ b/doc/src/sgml/storage.sgml
@@ -517,6 +517,15 @@ pages). There was no run time difference compared to an un-<acronym>TOAST</acron
 comparison table, in which all the HTML pages were cut down to 7 kB to fit.
 </para>
 
+<para>
+When you enable <xref linkend="guc-track-toast"/>, the system view
+<link linkend="monitoring-pg-stat-toast-view"><structname>pg_stat_toast</structname>
+</link> provides details on the number and effect of compression attempts,
+number of externalizations and some more useful information that enables you
+to decide if a different storage method and/or compression method would suite a
+column better.
+</para>
+
 </sect2>
 
 <sect2 id="storage-toast-inmemory">
@@ -1068,7 +1077,8 @@ data. Empty in ordinary tables.</entry>
   <type>struct varlena</type>, which includes the total length of the stored
   value and some flag bits.  Depending on the flags, the data can be either
   inline or in a <acronym>TOAST</acronym> table;
-  it might be compressed, too (see <xref linkend="storage-toast"/>).
+  it might be compressed, too (see <xref linkend="storage-toast"/> and 
+  <xref linkend="monitoring-pg-stat-toast-view"/>).
 
  </para>
  </sect2>
diff --git a/src/backend/access/table/toast_helper.c b/src/backend/access/table/toast_helper.c
index 013236b73d..f6b06e3329 100644
--- a/src/backend/access/table/toast_helper.c
+++ b/src/backend/access/table/toast_helper.c
@@ -19,6 +19,7 @@
 #include "access/toast_helper.h"
 #include "access/toast_internals.h"
 #include "catalog/pg_type_d.h"
+#include "pgstat.h"
 
 
 /*
@@ -229,7 +230,9 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 	Datum	   *value = &ttc->ttc_values[attribute];
 	Datum		new_value;
 	ToastAttrInfo *attr = &ttc->ttc_attr[attribute];
+	instr_time	start_time;
 
+	INSTR_TIME_SET_CURRENT(start_time);
 	new_value = toast_compress_datum(*value, attr->tai_compression);
 
 	if (DatumGetPointer(new_value) != NULL)
@@ -239,6 +242,12 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 			pfree(DatumGetPointer(*value));
 		*value = new_value;
 		attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
+		pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							attr->tai_size,
+							VARSIZE(DatumGetPointer(*value)),
+							start_time);
 		attr->tai_size = VARSIZE(DatumGetPointer(*value));
 		ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
 	}
@@ -246,6 +255,12 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 	{
 		/* incompressible, ignore on subsequent compression passes */
 		attr->tai_colflags |= TOASTCOL_INCOMPRESSIBLE;
+		pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							0,
+							0,
+							start_time);
 	}
 }
 
@@ -258,6 +273,9 @@ toast_tuple_externalize(ToastTupleContext *ttc, int attribute, int options)
 	Datum	   *value = &ttc->ttc_values[attribute];
 	Datum		old_value = *value;
 	ToastAttrInfo *attr = &ttc->ttc_attr[attribute];
+	instr_time	start_time;
+
+	INSTR_TIME_SET_CURRENT(start_time);
 
 	attr->tai_colflags |= TOASTCOL_IGNORE;
 	*value = toast_save_datum(ttc->ttc_rel, old_value, attr->tai_oldexternal,
@@ -266,6 +284,12 @@ toast_tuple_externalize(ToastTupleContext *ttc, int attribute, int options)
 		pfree(DatumGetPointer(old_value));
 	attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
 	ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
+	pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							true,
+							false,
+							0,
+							0,
+							start_time);
 }
 
 /*
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 61b515cdb8..3de3025488 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -1039,6 +1039,26 @@ CREATE VIEW pg_stat_user_functions AS
     WHERE P.prolang != 12  -- fast check to eliminate built-in functions
           AND pg_stat_get_function_calls(P.oid) IS NOT NULL;
 
+
+CREATE OR REPLACE VIEW pg_stat_toast AS
+ SELECT 
+    n.nspname AS schemaname,
+    a.attrelid AS reloid,
+    a.attnum AS attnum,
+    c.relname AS relname,
+    a.attname AS attname,
+    attstorage AS storagemethod,
+    pg_stat_get_toast_externalizations(a.attrelid,a.attnum) AS externalized,
+    attcompression AS compressmethod,
+    pg_stat_get_toast_compressions(a.attrelid,a.attnum) AS compressattempts,
+    pg_stat_get_toast_compressionsuccesses(a.attrelid,a.attnum) AS compresssuccesses,
+    pg_stat_get_toast_compressedsizesum(a.attrelid,a.attnum) AS compressedsize,
+    pg_stat_get_toast_originalsizesum(a.attrelid,a.attnum) AS originalsize,
+    pg_stat_get_toast_total_time(a.attrelid,a.attnum) AS total_time
+   FROM pg_attribute a
+   JOIN pg_class c ON c.oid = a.attrelid
+   LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
+  WHERE pg_stat_get_toast_externalizations(a.attrelid,a.attnum) IS NOT NULL;
 CREATE VIEW pg_stat_xact_user_functions AS
     SELECT
             P.oid AS funcid,
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 7264d2c727..5d7d269bf6 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -106,6 +106,7 @@
 #define PGSTAT_DB_HASH_SIZE		16
 #define PGSTAT_TAB_HASH_SIZE	512
 #define PGSTAT_FUNCTION_HASH_SIZE	512
+#define PGSTAT_TOAST_HASH_SIZE	512
 #define PGSTAT_SUBWORKER_HASH_SIZE	32
 #define PGSTAT_REPLSLOT_HASH_SIZE	32
 
@@ -116,6 +117,7 @@
  */
 bool		pgstat_track_counts = false;
 int			pgstat_track_functions = TRACK_FUNC_OFF;
+bool		pgstat_track_toast = true;
 
 /* ----------
  * Built from GUC parameter
@@ -228,6 +230,19 @@ static HTAB *pgStatFunctions = NULL;
  */
 static bool have_function_stats = false;
 
+/*
+ * Backends store per-toast-column info that's waiting to be sent to the collector
+ * in this hash table (indexed by column's PgStat_BackendAttrIdentifier).
+ */
+static HTAB *pgStatToastActions = NULL;
+
+
+/*
+ * Indicates if backend has some toast stats that it hasn't yet
+ * sent to the collector.
+ */
+static bool have_toast_stats = false;
+
 /*
  * Tuple insertion/deletion counts for an open transaction can't be propagated
  * into PgStat_TableStatus counters until we know if it is going to commit
@@ -328,7 +343,7 @@ static PgStat_StatSubWorkerEntry *pgstat_get_subworker_entry(PgStat_StatDBEntry
 static void pgstat_write_statsfiles(bool permanent, bool allDbs);
 static void pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent);
 static HTAB *pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep);
-static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 									 HTAB *subworkerhash, bool permanent);
 static void backend_read_statsfile(void);
 
@@ -340,6 +355,7 @@ static void pgstat_reset_replslot(PgStat_StatReplSlotEntry *slotstats, Timestamp
 
 static void pgstat_send_tabstat(PgStat_MsgTabstat *tsmsg, TimestampTz now);
 static void pgstat_send_funcstats(void);
+static void pgstat_send_toaststats(void);
 static void pgstat_send_slru(void);
 static void pgstat_send_subscription_purge(PgStat_MsgSubscriptionPurge *msg);
 static HTAB *pgstat_collect_oids(Oid catalogid, AttrNumber anum_oid);
@@ -373,6 +389,7 @@ static void pgstat_recv_wal(PgStat_MsgWal *msg, int len);
 static void pgstat_recv_slru(PgStat_MsgSLRU *msg, int len);
 static void pgstat_recv_funcstat(PgStat_MsgFuncstat *msg, int len);
 static void pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len);
+static void pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len);
 static void pgstat_recv_recoveryconflict(PgStat_MsgRecoveryConflict *msg, int len);
 static void pgstat_recv_deadlock(PgStat_MsgDeadlock *msg, int len);
 static void pgstat_recv_checksum_failure(PgStat_MsgChecksumFailure *msg, int len);
@@ -891,7 +908,7 @@ pgstat_report_stat(bool disconnect)
 		pgStatXactCommit == 0 && pgStatXactRollback == 0 &&
 		pgWalUsage.wal_records == prevWalUsage.wal_records &&
 		WalStats.m_wal_write == 0 && WalStats.m_wal_sync == 0 &&
-		!have_function_stats && !disconnect)
+		!have_function_stats && !have_toast_stats && !disconnect)
 		return;
 
 	/*
@@ -983,6 +1000,9 @@ pgstat_report_stat(bool disconnect)
 	/* Now, send function statistics */
 	pgstat_send_funcstats();
 
+	/* Now, send TOAST statistics */
+	pgstat_send_toaststats();
+
 	/* Send WAL statistics */
 	pgstat_send_wal(true);
 
@@ -1116,6 +1136,64 @@ pgstat_send_funcstats(void)
 	have_function_stats = false;
 }
 
+/*
+ * Subroutine for pgstat_report_stat: populate and send a toast stat message
+ */
+static void
+pgstat_send_toaststats(void)
+{
+	/* we assume this inits to all zeroes: */
+	static const PgStat_ToastCounts all_zeroes;
+
+	PgStat_MsgToaststat msg;
+	PgStat_BackendToastEntry *entry;
+	HASH_SEQ_STATUS tstat;
+
+	if (pgStatToastActions == NULL)
+		return;
+
+	pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_TOASTSTAT);
+	msg.m_databaseid = MyDatabaseId;
+	msg.m_nentries = 0;
+
+	hash_seq_init(&tstat, pgStatToastActions);
+	while ((entry = (PgStat_BackendToastEntry *) hash_seq_search(&tstat)) != NULL)
+	{
+		PgStat_ToastEntry *m_ent;
+
+		/* Skip it if no counts accumulated since last time */
+		if (memcmp(&entry->t_counts, &all_zeroes,
+				   sizeof(PgStat_ToastCounts)) == 0)
+			continue;
+
+		/* need to convert format of time accumulators */
+		m_ent = &msg.m_entry[msg.m_nentries];
+		m_ent->attr = entry->attr;
+		m_ent->t_numexternalized = entry->t_counts.t_numexternalized;
+		m_ent->t_numcompressed = entry->t_counts.t_numcompressed;
+		m_ent->t_numcompressionsuccess = entry->t_counts.t_numcompressionsuccess;
+		m_ent->t_size_orig = entry->t_counts.t_size_orig;
+		m_ent->t_size_compressed = entry->t_counts.t_size_compressed;
+		m_ent->t_comp_time = INSTR_TIME_GET_MICROSEC(entry->t_counts.t_comp_time);
+
+		if (++msg.m_nentries >= PGSTAT_NUM_TOASTENTRIES)
+		{
+			pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+						msg.m_nentries * sizeof(PgStat_ToastEntry));
+			msg.m_nentries = 0;
+		}
+
+		/* reset the entry's counts */
+		MemSet(&entry->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	if (msg.m_nentries > 0)
+		pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+					msg.m_nentries * sizeof(PgStat_ToastEntry));
+
+	have_toast_stats = false;
+}
+
 
 /* ----------
  * pgstat_vacuum_stat() -
@@ -2151,6 +2229,74 @@ pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu, bool finalize)
 	have_function_stats = true;
 }
 
+/*
+ * Report TOAST activity
+ * Called by toast_helper functions.
+ */
+void
+pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							instr_time start_time)
+{
+	PgStat_BackendAttrIdentifier toastattr = { relid, attr };
+	PgStat_BackendToastEntry *htabent;
+	instr_time	time_spent;
+	bool		found;
+
+	if (pgStatSock == PGINVALID_SOCKET || !pgstat_track_toast)
+		return;
+
+	if (!pgStatToastActions)
+	{
+		/* First time through - initialize toast stat table */
+		HASHCTL		hash_ctl;
+
+		hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+		hash_ctl.entrysize = sizeof(PgStat_BackendToastEntry);
+		pgStatToastActions = hash_create("TOAST stat entries",
+									  PGSTAT_TOAST_HASH_SIZE,
+									  &hash_ctl,
+									  HASH_ELEM | HASH_BLOBS);
+	}
+
+	/* Get the stats entry for this TOAST attribute, create if necessary */
+	htabent = hash_search(pgStatToastActions, &toastattr,
+						  HASH_ENTER, &found);
+	if (!found)
+	{
+		MemSet(&htabent->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	/* update counters */
+	if (externalized)
+	{
+		htabent->t_counts.t_numexternalized++;
+	}
+	if (compressed)
+	{
+		htabent->t_counts.t_numcompressed++;
+		if (new_size)
+		{
+			htabent->t_counts.t_size_orig+=old_size;
+			if (new_size)
+			{
+				htabent->t_counts.t_numcompressionsuccess++;
+				htabent->t_counts.t_size_compressed+=new_size;
+			}
+		}
+	}
+	/* record time spent */
+	INSTR_TIME_SET_CURRENT(time_spent);
+	INSTR_TIME_SUBTRACT(time_spent, start_time);
+	INSTR_TIME_ADD(htabent->t_counts.t_comp_time, time_spent);
+	
+	/* indicate that we have something to send */
+	have_toast_stats = true;
+}
+
 
 /* ----------
  * pgstat_initstats() -
@@ -3028,6 +3174,35 @@ pgstat_fetch_stat_subworker_entry(Oid subid, Oid subrelid)
 	return wentry;
 }
 
+/* ----------
+ * pgstat_fetch_stat_toastentry() -
+ *
+ *	Support function for the SQL-callable pgstat* functions. Returns
+ *	the collected statistics for one TOAST attribute or NULL.
+ * ----------
+ */
+PgStat_StatToastEntry *
+pgstat_fetch_stat_toastentry(Oid rel_id, int attr)
+{
+	PgStat_StatDBEntry *dbentry;
+	PgStat_BackendAttrIdentifier toast_id = { rel_id, attr };
+	PgStat_StatToastEntry *toastentry = NULL;
+
+	/* load the stats file if needed */
+	backend_read_statsfile();
+
+	/* Lookup our database, then find the requested TOAST activity stats.  */
+	dbentry = pgstat_fetch_stat_dbentry(MyDatabaseId);
+	if (dbentry != NULL && dbentry->toastactivity != NULL)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &toast_id,
+														 HASH_FIND, NULL);
+	}
+
+	return toastentry;
+}
+
 /*
  * ---------
  * pgstat_fetch_stat_archiver() -
@@ -3708,6 +3883,10 @@ PgstatCollectorMain(int argc, char *argv[])
 					pgstat_recv_funcpurge(&msg.msg_funcpurge, len);
 					break;
 
+				case PGSTAT_MTYPE_TOASTSTAT:
+					pgstat_recv_toaststat(&msg.msg_toaststat, len);
+					break;
+				
 				case PGSTAT_MTYPE_RECOVERYCONFLICT:
 					pgstat_recv_recoveryconflict(&msg.msg_recoveryconflict,
 												 len);
@@ -3852,6 +4031,14 @@ reset_dbentry_counters(PgStat_StatDBEntry *dbentry)
 									  PGSTAT_SUBWORKER_HASH_SIZE,
 									  &hash_ctl,
 									  HASH_ELEM | HASH_BLOBS);
+
+	hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+	hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+	dbentry->toastactivity = hash_create("Per-database TOAST",
+									 PGSTAT_TOAST_HASH_SIZE,
+									 &hash_ctl,
+									 HASH_ELEM | HASH_BLOBS);
+
 }
 
 /*
@@ -4059,8 +4246,8 @@ pgstat_write_statsfiles(bool permanent, bool allDbs)
 	while ((dbentry = (PgStat_StatDBEntry *) hash_seq_search(&hstat)) != NULL)
 	{
 		/*
-		 * Write out the table, function, and subscription-worker stats for
-		 * this DB into the appropriate per-DB stat file, if required.
+		 * Write out the table, function, TOAST and subscription-worker stats for this DB into the
+		 * appropriate per-DB stat file, if required.
 		 */
 		if (allDbs || pgstat_db_requested(dbentry->databaseid))
 		{
@@ -4175,9 +4362,11 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 	HASH_SEQ_STATUS tstat;
 	HASH_SEQ_STATUS fstat;
 	HASH_SEQ_STATUS sstat;
+	HASH_SEQ_STATUS ostat;
 	PgStat_StatTabEntry *tabentry;
 	PgStat_StatFuncEntry *funcentry;
 	PgStat_StatSubWorkerEntry *subwentry;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpout;
 	int32		format_id;
 	Oid			dbid = dbentry->databaseid;
@@ -4243,6 +4432,17 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 		(void) rc;				/* we'll check for error with ferror */
 	}
 
+	/*
+	 * Walk through the database's TOAST stats table.
+	 */
+	hash_seq_init(&ostat, dbentry->toastactivity);
+	while ((toastentry = (PgStat_StatToastEntry *) hash_seq_search(&ostat)) != NULL)
+	{
+		fputc('O', fpout);
+		rc = fwrite(toastentry, sizeof(PgStat_StatToastEntry), 1, fpout);
+		(void) rc;				/* we'll check for error with ferror */
+	}
+
 	/*
 	 * No more output to be done. Close the temp file and replace the old
 	 * pgstat.stat with it.  The ferror() check replaces testing for error
@@ -4483,6 +4683,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 				dbentry->tables = NULL;
 				dbentry->functions = NULL;
 				dbentry->subworkers = NULL;
+				dbentry->toastactivity = NULL;
 
 				/*
 				 * In the collector, disregard the timestamp we read from the
@@ -4528,6 +4729,14 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 												  &hash_ctl,
 												  HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
 
+				hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+				hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+				hash_ctl.hcxt = pgStatLocalContext;
+				dbentry->toastactivity = hash_create("Per-database toast information",
+												 PGSTAT_TOAST_HASH_SIZE,
+												 &hash_ctl,
+												 HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
+
 				/*
 				 * If requested, read the data from the database-specific
 				 * file.  Otherwise we just leave the hashtables empty.
@@ -4536,6 +4745,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 					pgstat_read_db_statsfile(dbentry->databaseid,
 											 dbentry->tables,
 											 dbentry->functions,
+											 dbentry->toastactivity,
 											 dbentry->subworkers,
 											 permanent);
 
@@ -4620,7 +4830,7 @@ done:
  * ----------
  */
 static void
-pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 						 HTAB *subworkerhash, bool permanent)
 {
 	PgStat_StatTabEntry *tabentry;
@@ -4629,6 +4839,8 @@ pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
 	PgStat_StatFuncEntry *funcentry;
 	PgStat_StatSubWorkerEntry subwbuf;
 	PgStat_StatSubWorkerEntry *subwentry;
+	PgStat_StatToastEntry toastbuf;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpin;
 	int32		format_id;
 	bool		found;
@@ -4777,6 +4989,32 @@ pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
 				memcpy(subwentry, &subwbuf, sizeof(subwbuf));
 				break;
 
+
+				/*
+				 * 'O'	A PgStat_StatToastEntry follows (tOast)
+				 */
+			case 'O':
+				if (fread(&toastbuf, 1, sizeof(PgStat_StatToastEntry),
+						  fpin) != sizeof(PgStat_StatToastEntry))
+				{
+					ereport(pgStatRunningInCollector ? LOG : WARNING,
+							(errmsg("corrupted statistics file \"%s\"",
+									statfile)));
+					goto done;
+				}
+
+				/*
+				 * Skip if TOAST data not wanted.
+				 */
+				if (toasthash == NULL)
+					break;
+
+				toastentry = (PgStat_StatToastEntry *) hash_search(toasthash,
+																 (void *) &toastbuf.t_id,
+																 HASH_ENTER, &found);
+				memcpy(toastentry, &toastbuf, sizeof(toastbuf));
+				break;
+
 				/*
 				 * 'E'	The EOF marker of a complete stats file.
 				 */
@@ -5452,6 +5690,8 @@ pgstat_recv_dropdb(PgStat_MsgDropdb *msg, int len)
 			hash_destroy(dbentry->functions);
 		if (dbentry->subworkers != NULL)
 			hash_destroy(dbentry->subworkers);
+		if (dbentry->toastactivity != NULL)
+			hash_destroy(dbentry->toastactivity);
 
 		if (hash_search(pgStatDBHash,
 						(void *) &dbid,
@@ -5491,10 +5731,12 @@ pgstat_recv_resetcounter(PgStat_MsgResetcounter *msg, int len)
 		hash_destroy(dbentry->functions);
 	if (dbentry->subworkers != NULL)
 		hash_destroy(dbentry->subworkers);
-
+	if (dbentry->toastactivity != NULL)
+		hash_destroy(dbentry->toastactivity);
 	dbentry->tables = NULL;
 	dbentry->functions = NULL;
 	dbentry->subworkers = NULL;
+	dbentry->toastactivity = NULL;
 
 	/*
 	 * Reset database-level stats, too.  This creates empty hash tables for
@@ -6152,6 +6394,60 @@ pgstat_recv_subscription_purge(PgStat_MsgSubscriptionPurge *msg, int len)
 	}
 }
 
+/* ----------
+ * pgstat_recv_toaststat() -
+ *
+ *	Count what the backend has done.
+ * ----------
+ */
+static void
+pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len)
+{
+	PgStat_ToastEntry *toastmsg = &(msg->m_entry[0]);
+	PgStat_StatDBEntry *dbentry;
+	PgStat_StatToastEntry *toastentry;
+	int			i;
+	bool		found;
+
+	dbentry = pgstat_get_db_entry(msg->m_databaseid, true);
+
+	/*
+	 * Process all TOAST entries in the message.
+	 */
+	for (i = 0; i < msg->m_nentries; i++, toastmsg++)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &(toastmsg->attr),
+														 HASH_ENTER, &found);
+
+		if (!found)
+		{
+			/*
+			 * If it's a new entry, initialize counters to the values
+			 * we just got.
+			 */
+			toastentry->t_numexternalized = toastmsg->t_numexternalized;
+			toastentry->t_numcompressed = toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess = toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_orig = toastmsg->t_size_orig;
+			toastentry->t_size_compressed = toastmsg->t_size_compressed;
+			toastentry->t_comp_time = toastmsg->t_comp_time;
+		}
+		else
+		{
+			/*
+			 * Otherwise add the values to the existing entry.
+			 */
+			toastentry->t_numexternalized += toastmsg->t_numexternalized;
+			toastentry->t_numcompressed += toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess += toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_orig += toastmsg->t_size_orig;
+			toastentry->t_size_compressed += toastmsg->t_size_compressed;
+			toastentry->t_comp_time += toastmsg->t_comp_time;
+		}
+	}
+}
+
 /* ----------
  * pgstat_recv_subworker_error() -
  *
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index f529c1561a..8b40c43626 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -410,6 +410,78 @@ pg_stat_get_function_self_time(PG_FUNCTION_ARGS)
 	PG_RETURN_FLOAT8(((double) funcentry->f_self_time) / 1000.0);
 }
 
+Datum
+pg_stat_get_toast_externalizations(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numexternalized);
+}
+
+Datum
+pg_stat_get_toast_compressions(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressed);
+}
+
+Datum
+pg_stat_get_toast_compressionsuccesses(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressionsuccess);
+}
+
+Datum
+pg_stat_get_toast_originalsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_orig);
+}
+
+Datum
+pg_stat_get_toast_compressedsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_compressed);
+}
+
+Datum
+pg_stat_get_toast_total_time(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_comp_time);
+}
+
 Datum
 pg_stat_get_backend_idset(PG_FUNCTION_ARGS)
 {
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 7b03046301..ed3f59fc06 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -1540,6 +1540,15 @@ static struct config_bool ConfigureNamesBool[] =
 		true,
 		NULL, NULL, NULL
 	},
+	{
+		{"track_toast", PGC_SUSET, STATS_COLLECTOR,
+			gettext_noop("Collects statistics on TOAST activity."),
+			NULL
+		},
+		&pgstat_track_toast,
+		false,
+		NULL, NULL, NULL
+	},
 	{
 		{"track_io_timing", PGC_SUSET, STATS_COLLECTOR,
 			gettext_noop("Collects timing statistics for database I/O activity."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index a1acd46b61..12f4bb1a38 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -607,6 +607,7 @@
 #track_io_timing = off
 #track_wal_io_timing = off
 #track_functions = none			# none, pl, all
+#track_toast = off
 #stats_temp_directory = 'pg_stat_tmp'
 
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 4d992dc224..22c34b96a6 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5668,6 +5668,31 @@
   proparallel => 'r', prorettype => 'float8', proargtypes => 'oid',
   prosrc => 'pg_stat_get_function_self_time' },
 
+{ oid => '9700', descr => 'statistics: number of TOAST externalizations',
+  proname => 'pg_stat_get_toast_externalizations', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_externalizations' },
+{ oid => '9701', descr => 'statistics: number of TOAST compressions',
+  proname => 'pg_stat_get_toast_compressions', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressions' },
+  { oid => '9702', descr => 'statistics: number of successful TOAST compressions',
+  proname => 'pg_stat_get_toast_compressionsuccesses', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressionsuccesses' },
+{ oid => '9703', descr => 'statistics: total original size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_originalsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_originalsizesum' },
+{ oid => '9704', descr => 'statistics: total compressed size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_compressedsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressedsizesum' },
+{ oid => '9705', descr => 'statistics: total time spend TOASTing data',
+  proname => 'pg_stat_get_toast_total_time', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_total_time' },
+
 { oid => '3037',
   descr => 'statistics: number of scans done for table/index in current transaction',
   proname => 'pg_stat_get_xact_numscans', provolatile => 'v',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5b51b58e5a..ff26aec404 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -82,10 +82,12 @@ typedef enum StatMsgType
 	PGSTAT_MTYPE_DEADLOCK,
 	PGSTAT_MTYPE_CHECKSUMFAILURE,
 	PGSTAT_MTYPE_REPLSLOT,
+	PGSTAT_MTYPE_CONNECTION,
 	PGSTAT_MTYPE_CONNECT,
 	PGSTAT_MTYPE_DISCONNECT,
 	PGSTAT_MTYPE_SUBSCRIPTIONPURGE,
 	PGSTAT_MTYPE_SUBWORKERERROR,
+	PGSTAT_MTYPE_TOASTSTAT,
 } StatMsgType;
 
 /* ----------
@@ -733,6 +735,80 @@ typedef struct PgStat_MsgDisconnect
 	SessionEndType m_cause;
 } PgStat_MsgDisconnect;
 
+/* ----------
+ * PgStat_BackendAttrIdentifier	Identifier for a single attribute/column (OID + attr)
+ * Used as a hashable identifier for (e.g.) TOAST columns
+ * ----------
+ */
+typedef struct PgStat_BackendAttrIdentifier
+{
+	Oid			relid;
+	int			attr;
+} PgStat_BackendAttrIdentifier;
+
+/* ----------
+ * PgStat_ToastCounts	The actual per-TOAST counts kept by a backend
+ *
+ * This struct should contain only actual event counters, because we memcmp
+ * it against zeroes to detect whether there are any counts to transmit.
+ *
+ * Note that the time counters are in instr_time format here.  We convert to
+ * microseconds in PgStat_Counter format when transmitting to the collector.
+ * ----------
+ */
+typedef struct PgStat_ToastCounts
+{
+	PgStat_Counter	t_numexternalized;
+	PgStat_Counter	t_numcompressed;
+	PgStat_Counter	t_numcompressionsuccess;
+	uint64		t_size_orig;
+	uint64		t_size_compressed;
+	instr_time	t_comp_time;
+} PgStat_ToastCounts;
+
+/* ----------
+ * PgStat_BackendToastEntry	Entry in backend's per-toast-attr hash table
+ * ----------
+ */
+typedef struct PgStat_BackendToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_ToastCounts 		t_counts;
+} PgStat_BackendToastEntry;
+
+/* ----------
+ * PgStat_ToastEntry			Per-TOAST-column info in a MsgFuncstat
+ * ----------
+ */
+typedef struct PgStat_ToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_Counter 			t_numexternalized;
+	PgStat_Counter 			t_numcompressed;
+	PgStat_Counter 			t_numcompressionsuccess;
+	uint64		   		t_size_orig;
+	uint64		   		t_size_compressed;
+	PgStat_Counter			t_comp_time;	/* time in microseconds */
+} PgStat_ToastEntry;
+
+/* ----------
+ * PgStat_MsgToaststat			Sent by the backend to report function
+ *								usage statistics.
+ * ----------
+ */
+#define PGSTAT_NUM_TOASTENTRIES	\
+	((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - sizeof(int))  \
+	 / sizeof(PgStat_ToastEntry))
+
+typedef struct PgStat_MsgToaststat
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+	int			m_nentries;
+	PgStat_ToastEntry m_entry[PGSTAT_NUM_TOASTENTRIES];
+} PgStat_MsgToaststat;
+
+
 /* ----------
  * PgStat_Msg					Union over all possible messages.
  * ----------
@@ -760,6 +836,7 @@ typedef union PgStat_Msg
 	PgStat_MsgSLRU msg_slru;
 	PgStat_MsgFuncstat msg_funcstat;
 	PgStat_MsgFuncpurge msg_funcpurge;
+	PgStat_MsgToaststat msg_toaststat;
 	PgStat_MsgRecoveryConflict msg_recoveryconflict;
 	PgStat_MsgDeadlock msg_deadlock;
 	PgStat_MsgTempFile msg_tempfile;
@@ -833,6 +910,7 @@ typedef struct PgStat_StatDBEntry
 	HTAB	   *tables;
 	HTAB	   *functions;
 	HTAB	   *subworkers;
+	HTAB	   *toastactivity;
 } PgStat_StatDBEntry;
 
 
@@ -1022,6 +1100,22 @@ typedef struct PgStat_StatSubWorkerEntry
 	char		last_error_message[PGSTAT_SUBWORKERERROR_MSGLEN];
 } PgStat_StatSubWorkerEntry;
 
+/* ----------
+ * PgStat_StatToastEntry			The collector's data per TOAST attribute
+ * ----------
+ */
+typedef struct PgStat_StatToastEntry
+{
+	PgStat_BackendAttrIdentifier t_id;
+	PgStat_Counter t_numexternalized;
+	PgStat_Counter t_numcompressed;
+	PgStat_Counter t_numcompressionsuccess;
+	uint64		   t_size_orig;
+	uint64		   t_size_compressed;
+	PgStat_Counter t_comp_time;	/* time in microseconds */
+} PgStat_StatToastEntry;
+
+
 /*
  * Working state needed to accumulate per-function-call timing statistics.
  */
@@ -1045,6 +1139,7 @@ typedef struct PgStat_FunctionCallUsage
  */
 extern PGDLLIMPORT bool pgstat_track_counts;
 extern PGDLLIMPORT int pgstat_track_functions;
+extern PGDLLIMPORT bool pgstat_track_toast;
 extern char *pgstat_stat_directory;
 extern char *pgstat_stat_tmpname;
 extern char *pgstat_stat_filename;
@@ -1196,12 +1291,22 @@ extern void pgstat_count_heap_delete(Relation rel);
 extern void pgstat_count_truncate(Relation rel);
 extern void pgstat_update_heap_dead_tuples(Relation rel, int delta);
 
+extern void pgstat_count_toast_insert(Relation rel, PgStat_Counter n);
+
 struct FunctionCallInfoBaseData;
 extern void pgstat_init_function_usage(struct FunctionCallInfoBaseData *fcinfo,
 									   PgStat_FunctionCallUsage *fcu);
 extern void pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu,
 									  bool finalize);
 
+extern void
+pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							instr_time start_time);
+
 extern void AtEOXact_PgStat(bool isCommit, bool parallel);
 extern void AtEOSubXact_PgStat(bool isCommit, int nestDepth);
 
@@ -1228,9 +1333,12 @@ extern PgStat_StatTabEntry *pgstat_fetch_stat_tabentry(Oid relid);
 extern PgStat_StatFuncEntry *pgstat_fetch_stat_funcentry(Oid funcid);
 extern PgStat_StatSubWorkerEntry *pgstat_fetch_stat_subworker_entry(Oid subid,
 																	Oid subrelid);
+extern PgStat_StatToastEntry *pgstat_fetch_stat_toastentry(Oid rel_id, int attr);
+extern PgStat_ArchiverStats *pgstat_fetch_stat_archiver(void);
 extern PgStat_ArchiverStats *pgstat_fetch_stat_archiver(void);
 extern PgStat_BgWriterStats *pgstat_fetch_stat_bgwriter(void);
 extern PgStat_CheckpointerStats *pgstat_fetch_stat_checkpointer(void);
+
 extern PgStat_GlobalStats *pgstat_fetch_global(void);
 extern PgStat_WalStats *pgstat_fetch_stat_wal(void);
 extern PgStat_SLRUStats *pgstat_fetch_slru(void);
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index b58b062b10..2b49bebcb8 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -2147,6 +2147,23 @@ pg_stat_sys_tables| SELECT pg_stat_all_tables.relid,
     pg_stat_all_tables.autoanalyze_count
    FROM pg_stat_all_tables
   WHERE ((pg_stat_all_tables.schemaname = ANY (ARRAY['pg_catalog'::name, 'information_schema'::name])) OR (pg_stat_all_tables.schemaname ~ '^pg_toast'::text));
+pg_stat_toast| SELECT n.nspname AS schemaname,
+    a.attrelid AS reloid,
+    a.attnum,
+    c.relname,
+    a.attname,
+    a.attstorage AS storagemethod,
+    pg_stat_get_toast_externalizations(a.attrelid, (a.attnum)::integer) AS externalized,
+    a.attcompression AS compressmethod,
+    pg_stat_get_toast_compressions(a.attrelid, (a.attnum)::integer) AS compressattempts,
+    pg_stat_get_toast_compressionsuccesses(a.attrelid, (a.attnum)::integer) AS compresssuccesses,
+    pg_stat_get_toast_compressedsizesum(a.attrelid, (a.attnum)::integer) AS compressedsize,
+    pg_stat_get_toast_originalsizesum(a.attrelid, (a.attnum)::integer) AS originalsize,
+    pg_stat_get_toast_total_time(a.attrelid, (a.attnum)::integer) AS total_time
+   FROM ((pg_attribute a
+     JOIN pg_class c ON ((c.oid = a.attrelid)))
+     LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace)))
+  WHERE (pg_stat_get_toast_externalizations(a.attrelid, (a.attnum)::integer) IS NOT NULL);
 pg_stat_user_functions| SELECT p.oid AS funcid,
     n.nspname AS schemaname,
     p.proname AS funcname,
-- 
2.32.0

diff --git a/src/test/modules/Makefile b/src/test/modules/Makefile
index dffc79b2d9..5ccc82b4b5 100644
--- a/src/test/modules/Makefile
+++ b/src/test/modules/Makefile
@@ -27,6 +27,7 @@ SUBDIRS = \
 		  test_regex \
 		  test_rls_hooks \
 		  test_shm_mq \
+		  track_toast \
 		  unsafe_tests \
 		  worker_spi
 
diff --git a/src/test/modules/track_toast/.gitignore b/src/test/modules/track_toast/.gitignore
new file mode 100644
index 0000000000..5dcb3ff972
--- /dev/null
+++ b/src/test/modules/track_toast/.gitignore
@@ -0,0 +1,4 @@
+# Generated subdirectories
+/log/
+/results/
+/tmp_check/
diff --git a/src/test/modules/track_toast/Makefile b/src/test/modules/track_toast/Makefile
new file mode 100644
index 0000000000..26089b3deb
--- /dev/null
+++ b/src/test/modules/track_toast/Makefile
@@ -0,0 +1,18 @@
+# src/test/modules/track_toast/Makefile
+
+REGRESS = track_toast
+REGRESS_OPTS = --temp-config=$(top_srcdir)/src/test/modules/track_toast/track_toast.conf
+# Disabled because these tests require "track_toast = on",
+# which typical installcheck users do not have (e.g. buildfarm clients).
+NO_INSTALLCHECK = 1
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/test/modules/track_toast
+top_builddir = ../../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
diff --git a/src/test/modules/track_toast/expected/track_toast.out b/src/test/modules/track_toast/expected/track_toast.out
new file mode 100644
index 0000000000..39321f0340
--- /dev/null
+++ b/src/test/modules/track_toast/expected/track_toast.out
@@ -0,0 +1,6 @@
+SELECT 'TEST';
+ ?column? 
+----------
+ TEST
+(1 row)
+
diff --git a/src/test/modules/track_toast/sql/track_toast.sql b/src/test/modules/track_toast/sql/track_toast.sql
new file mode 100644
index 0000000000..a41415f61b
--- /dev/null
+++ b/src/test/modules/track_toast/sql/track_toast.sql
@@ -0,0 +1 @@
+SELECT 'TEST';
\ No newline at end of file
diff --git a/src/test/modules/track_toast/track_toast.conf b/src/test/modules/track_toast/track_toast.conf
new file mode 100644
index 0000000000..191f40a762
--- /dev/null
+++ b/src/test/modules/track_toast/track_toast.conf
@@ -0,0 +1 @@
+track_toast = on
\ No newline at end of file

diff --git a/.gitignore b/.gitignore
index 794e35b73c..ca2ee84742 100644
--- a/.gitignore
+++ b/.gitignore
@@ -31,6 +31,8 @@ win32ver.rc
 *.exe
 lib*dll.def
 lib*.pc
+tags
+/.vscode
 
 # Local excludes in root directory
 /GNUmakefile
@@ -42,3 +44,5 @@ lib*.pc
 /Debug/
 /Release/
 /tmp_install/
+.gitignore
+pg_stat_toast.*
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index afbb6c35e3..fa40befc16 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -7668,6 +7668,32 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv;
       </listitem>
      </varlistentry>
 
+     <varlistentry id="guc-track-toast" xreflabel="track_toast">
+      <term><varname>track_toast</varname> (<type>boolean</type>)
+      <indexterm>
+       <primary><varname>track_toast</varname> configuration parameter</primary>
+      </indexterm>
+      </term>
+      <listitem>
+       <para>
+        Enables tracking of <link linkend="storage-toast">TOAST</link> activities.
+        Compressions and externalizations are tracked.
+        The default is <literal>off</literal>.
+        Only superusers can change this setting.
+       </para>
+
+       <note>
+        <para>
+        Be aware that this feature, depending on the amount of TOASTable columns in
+        your databases, may significantly increase the size of the statistics files
+        and the workload of the statistics collector. It is recommended to only
+        temporarily activate this to assess the right compression and storage method
+        for (a) column(s).
+        </para>
+       </note>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="guc-stats-temp-directory" xreflabel="stats_temp_directory">
       <term><varname>stats_temp_directory</varname> (<type>string</type>)
       <indexterm>
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 62f2a3332b..32d7818096 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -610,6 +610,17 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
       yet included in <structname>pg_stat_user_functions</structname>).</entry>
      </row>
 
+     <row>
+      <entry><structname>pg_stat_toast</structname><indexterm><primary>pg_stat_toast</primary></indexterm></entry>
+      <entry>
+       One row for each column that has ever been TOASTed (compressed and/or externalized).
+       Showing the number of externalizations, compression attempts / successes, compressed and
+       uncompressed sizes etc.
+       <link linkend="monitoring-pg-stat-toast-view">
+       <structname>pg_stat_toast</structname></link> for details.
+      </entry>
+     </row>
+
      <row>
       <entry><structname>pg_stat_slru</structname><indexterm><primary>pg_stat_slru</primary></indexterm></entry>
       <entry>One row per SLRU, showing statistics of operations. See
@@ -4969,6 +4980,158 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
 
  </sect2>
 
+ <sect2 id="monitoring-pg-stat-toast-view">
+  <title><structname>pg_stat_toast</structname></title>
+
+  <indexterm>
+   <primary>pg_stat_toast</primary>
+  </indexterm>
+
+  <para>
+   The <structname>pg_stat_toast</structname> view will contain
+   one row for each column of variable size that has been TOASTed since 
+   the last statistics reset. The <xref linkend="guc-track-toast"/> parameter
+   controls whether TOAST activities are tracked or not.
+  </para>
+
+  <table id="pg-stat-toast-view" xreflabel="pg_stat_toast">
+   <title><structname>pg_stat_toast</structname> View</title>
+   <tgroup cols="1">
+    <thead>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       Column Type
+      </para>
+      <para>
+       Description
+      </para></entry>
+     </row>
+    </thead>
+
+    <tbody>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>schemaname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the schema the relation is in
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>reloid</structfield> <type>oid</type>
+      </para>
+      <para>
+       OID of the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>attnum</structfield> <type>int</type>
+      </para>
+      <para>
+       Attribute (column) number in the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>relname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>attname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the attribute (column)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>storagemethod</structfield> <type>char</type>
+      </para>
+      <para>
+       Storage method of the attribute
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>externalized</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times this attribute was externalized (pushed to TOAST relation)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressmethod</structfield> <type>char</type>
+      </para>
+      <para>
+       Compression method of the attribute (empty means default)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressattempts</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times this attribute was compressed
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compresssuccesses</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times the compression was successful (gained a size reduction)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressedsize</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total size of all compressed datums
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>originalsize</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total size of all compressed datums before compression
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>total_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Total time spent TOASTing this attribute, in microseconds.
+      </para></entry>
+     </row>
+
+    </tbody>
+   </tgroup>
+  </table>
+
+ </sect2>
+
  <sect2 id="monitoring-pg-stat-slru-view">
   <title><structname>pg_stat_slru</structname></title>
 
diff --git a/doc/src/sgml/storage.sgml b/doc/src/sgml/storage.sgml
index 7136bbe7a3..2a47922573 100644
--- a/doc/src/sgml/storage.sgml
+++ b/doc/src/sgml/storage.sgml
@@ -517,6 +517,15 @@ pages). There was no run time difference compared to an un-<acronym>TOAST</acron
 comparison table, in which all the HTML pages were cut down to 7 kB to fit.
 </para>
 
+<para>
+When you enable <xref linkend="guc-track-toast"/>, the system view
+<link linkend="monitoring-pg-stat-toast-view"><structname>pg_stat_toast</structname>
+</link> provides details on the number and effect of compression attempts,
+number of externalizations and some more useful information that enables you
+to decide if a different storage method and/or compression method would suite a
+column better.
+</para>
+
 </sect2>
 
 <sect2 id="storage-toast-inmemory">
@@ -1068,7 +1077,8 @@ data. Empty in ordinary tables.</entry>
   <type>struct varlena</type>, which includes the total length of the stored
   value and some flag bits.  Depending on the flags, the data can be either
   inline or in a <acronym>TOAST</acronym> table;
-  it might be compressed, too (see <xref linkend="storage-toast"/>).
+  it might be compressed, too (see <xref linkend="storage-toast"/> and 
+  <xref linkend="monitoring-pg-stat-toast-view"/>).
 
  </para>
  </sect2>
diff --git a/src/backend/access/table/toast_helper.c b/src/backend/access/table/toast_helper.c
index 013236b73d..f6b06e3329 100644
--- a/src/backend/access/table/toast_helper.c
+++ b/src/backend/access/table/toast_helper.c
@@ -19,6 +19,7 @@
 #include "access/toast_helper.h"
 #include "access/toast_internals.h"
 #include "catalog/pg_type_d.h"
+#include "pgstat.h"
 
 
 /*
@@ -229,7 +230,9 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 	Datum	   *value = &ttc->ttc_values[attribute];
 	Datum		new_value;
 	ToastAttrInfo *attr = &ttc->ttc_attr[attribute];
+	instr_time	start_time;
 
+	INSTR_TIME_SET_CURRENT(start_time);
 	new_value = toast_compress_datum(*value, attr->tai_compression);
 
 	if (DatumGetPointer(new_value) != NULL)
@@ -239,6 +242,12 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 			pfree(DatumGetPointer(*value));
 		*value = new_value;
 		attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
+		pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							attr->tai_size,
+							VARSIZE(DatumGetPointer(*value)),
+							start_time);
 		attr->tai_size = VARSIZE(DatumGetPointer(*value));
 		ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
 	}
@@ -246,6 +255,12 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 	{
 		/* incompressible, ignore on subsequent compression passes */
 		attr->tai_colflags |= TOASTCOL_INCOMPRESSIBLE;
+		pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							0,
+							0,
+							start_time);
 	}
 }
 
@@ -258,6 +273,9 @@ toast_tuple_externalize(ToastTupleContext *ttc, int attribute, int options)
 	Datum	   *value = &ttc->ttc_values[attribute];
 	Datum		old_value = *value;
 	ToastAttrInfo *attr = &ttc->ttc_attr[attribute];
+	instr_time	start_time;
+
+	INSTR_TIME_SET_CURRENT(start_time);
 
 	attr->tai_colflags |= TOASTCOL_IGNORE;
 	*value = toast_save_datum(ttc->ttc_rel, old_value, attr->tai_oldexternal,
@@ -266,6 +284,12 @@ toast_tuple_externalize(ToastTupleContext *ttc, int attribute, int options)
 		pfree(DatumGetPointer(old_value));
 	attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
 	ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
+	pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							true,
+							false,
+							0,
+							0,
+							start_time);
 }
 
 /*
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 61b515cdb8..3de3025488 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -1039,6 +1039,26 @@ CREATE VIEW pg_stat_user_functions AS
     WHERE P.prolang != 12  -- fast check to eliminate built-in functions
           AND pg_stat_get_function_calls(P.oid) IS NOT NULL;
 
+
+CREATE OR REPLACE VIEW pg_stat_toast AS
+ SELECT 
+    n.nspname AS schemaname,
+    a.attrelid AS reloid,
+    a.attnum AS attnum,
+    c.relname AS relname,
+    a.attname AS attname,
+    attstorage AS storagemethod,
+    pg_stat_get_toast_externalizations(a.attrelid,a.attnum) AS externalized,
+    attcompression AS compressmethod,
+    pg_stat_get_toast_compressions(a.attrelid,a.attnum) AS compressattempts,
+    pg_stat_get_toast_compressionsuccesses(a.attrelid,a.attnum) AS compresssuccesses,
+    pg_stat_get_toast_compressedsizesum(a.attrelid,a.attnum) AS compressedsize,
+    pg_stat_get_toast_originalsizesum(a.attrelid,a.attnum) AS originalsize,
+    pg_stat_get_toast_total_time(a.attrelid,a.attnum) AS total_time
+   FROM pg_attribute a
+   JOIN pg_class c ON c.oid = a.attrelid
+   LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
+  WHERE pg_stat_get_toast_externalizations(a.attrelid,a.attnum) IS NOT NULL;
 CREATE VIEW pg_stat_xact_user_functions AS
     SELECT
             P.oid AS funcid,
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 7264d2c727..c4ce619257 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -106,6 +106,7 @@
 #define PGSTAT_DB_HASH_SIZE		16
 #define PGSTAT_TAB_HASH_SIZE	512
 #define PGSTAT_FUNCTION_HASH_SIZE	512
+#define PGSTAT_TOAST_HASH_SIZE	64
 #define PGSTAT_SUBWORKER_HASH_SIZE	32
 #define PGSTAT_REPLSLOT_HASH_SIZE	32
 
@@ -116,6 +117,7 @@
  */
 bool		pgstat_track_counts = false;
 int			pgstat_track_functions = TRACK_FUNC_OFF;
+bool		pgstat_track_toast = false;
 
 /* ----------
  * Built from GUC parameter
@@ -228,6 +230,19 @@ static HTAB *pgStatFunctions = NULL;
  */
 static bool have_function_stats = false;
 
+/*
+ * Backends store per-toast-column info that's waiting to be sent to the collector
+ * in this hash table (indexed by column's PgStat_BackendAttrIdentifier).
+ */
+static HTAB *pgStatToastActions = NULL;
+
+
+/*
+ * Indicates if backend has some toast stats that it hasn't yet
+ * sent to the collector.
+ */
+static bool have_toast_stats = false;
+
 /*
  * Tuple insertion/deletion counts for an open transaction can't be propagated
  * into PgStat_TableStatus counters until we know if it is going to commit
@@ -328,7 +343,7 @@ static PgStat_StatSubWorkerEntry *pgstat_get_subworker_entry(PgStat_StatDBEntry
 static void pgstat_write_statsfiles(bool permanent, bool allDbs);
 static void pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent);
 static HTAB *pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep);
-static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 									 HTAB *subworkerhash, bool permanent);
 static void backend_read_statsfile(void);
 
@@ -340,6 +355,7 @@ static void pgstat_reset_replslot(PgStat_StatReplSlotEntry *slotstats, Timestamp
 
 static void pgstat_send_tabstat(PgStat_MsgTabstat *tsmsg, TimestampTz now);
 static void pgstat_send_funcstats(void);
+static void pgstat_send_toaststats(void);
 static void pgstat_send_slru(void);
 static void pgstat_send_subscription_purge(PgStat_MsgSubscriptionPurge *msg);
 static HTAB *pgstat_collect_oids(Oid catalogid, AttrNumber anum_oid);
@@ -373,6 +389,7 @@ static void pgstat_recv_wal(PgStat_MsgWal *msg, int len);
 static void pgstat_recv_slru(PgStat_MsgSLRU *msg, int len);
 static void pgstat_recv_funcstat(PgStat_MsgFuncstat *msg, int len);
 static void pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len);
+static void pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len);
 static void pgstat_recv_recoveryconflict(PgStat_MsgRecoveryConflict *msg, int len);
 static void pgstat_recv_deadlock(PgStat_MsgDeadlock *msg, int len);
 static void pgstat_recv_checksum_failure(PgStat_MsgChecksumFailure *msg, int len);
@@ -891,7 +908,7 @@ pgstat_report_stat(bool disconnect)
 		pgStatXactCommit == 0 && pgStatXactRollback == 0 &&
 		pgWalUsage.wal_records == prevWalUsage.wal_records &&
 		WalStats.m_wal_write == 0 && WalStats.m_wal_sync == 0 &&
-		!have_function_stats && !disconnect)
+		!have_function_stats && !have_toast_stats && !disconnect)
 		return;
 
 	/*
@@ -983,6 +1000,9 @@ pgstat_report_stat(bool disconnect)
 	/* Now, send function statistics */
 	pgstat_send_funcstats();
 
+	/* Now, send TOAST statistics */
+	pgstat_send_toaststats();
+
 	/* Send WAL statistics */
 	pgstat_send_wal(true);
 
@@ -1116,6 +1136,64 @@ pgstat_send_funcstats(void)
 	have_function_stats = false;
 }
 
+/*
+ * Subroutine for pgstat_report_stat: populate and send a toast stat message
+ */
+static void
+pgstat_send_toaststats(void)
+{
+	/* we assume this inits to all zeroes: */
+	static const PgStat_ToastCounts all_zeroes;
+
+	PgStat_MsgToaststat msg;
+	PgStat_BackendToastEntry *entry;
+	HASH_SEQ_STATUS tstat;
+
+	if (pgStatToastActions == NULL)
+		return;
+
+	pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_TOASTSTAT);
+	msg.m_databaseid = MyDatabaseId;
+	msg.m_nentries = 0;
+
+	hash_seq_init(&tstat, pgStatToastActions);
+	while ((entry = (PgStat_BackendToastEntry *) hash_seq_search(&tstat)) != NULL)
+	{
+		PgStat_ToastEntry *m_ent;
+
+		/* Skip it if no counts accumulated since last time */
+		if (memcmp(&entry->t_counts, &all_zeroes,
+				   sizeof(PgStat_ToastCounts)) == 0)
+			continue;
+
+		/* need to convert format of time accumulators */
+		m_ent = &msg.m_entry[msg.m_nentries];
+		m_ent->attr = entry->attr;
+		m_ent->t_numexternalized = entry->t_counts.t_numexternalized;
+		m_ent->t_numcompressed = entry->t_counts.t_numcompressed;
+		m_ent->t_numcompressionsuccess = entry->t_counts.t_numcompressionsuccess;
+		m_ent->t_size_orig = entry->t_counts.t_size_orig;
+		m_ent->t_size_compressed = entry->t_counts.t_size_compressed;
+		m_ent->t_comp_time = INSTR_TIME_GET_MICROSEC(entry->t_counts.t_comp_time);
+
+		if (++msg.m_nentries >= PGSTAT_NUM_TOASTENTRIES)
+		{
+			pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+						msg.m_nentries * sizeof(PgStat_ToastEntry));
+			msg.m_nentries = 0;
+		}
+
+		/* reset the entry's counts */
+		MemSet(&entry->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	if (msg.m_nentries > 0)
+		pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+					msg.m_nentries * sizeof(PgStat_ToastEntry));
+
+	have_toast_stats = false;
+}
+
 
 /* ----------
  * pgstat_vacuum_stat() -
@@ -2151,6 +2229,75 @@ pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu, bool finalize)
 	have_function_stats = true;
 }
 
+/*
+ * Report TOAST activity
+ * Called by toast_helper functions.
+ */
+void
+pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							instr_time start_time)
+{
+	PgStat_BackendAttrIdentifier toastattr = { relid, attr };
+	PgStat_BackendToastEntry *htabent;
+	instr_time	time_spent;
+	bool		found;
+
+	if (pgStatSock == PGINVALID_SOCKET || !pgstat_track_toast)
+		return;
+
+	INSTR_TIME_SET_CURRENT(time_spent);
+	INSTR_TIME_SUBTRACT(time_spent, start_time);
+
+	if (!pgStatToastActions)
+	{
+		/* First time through - initialize toast stat table */
+		HASHCTL		hash_ctl;
+
+		hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+		hash_ctl.entrysize = sizeof(PgStat_BackendToastEntry);
+		pgStatToastActions = hash_create("TOAST stat entries",
+									  PGSTAT_TOAST_HASH_SIZE,
+									  &hash_ctl,
+									  HASH_ELEM | HASH_BLOBS);
+	}
+
+	/* Get the stats entry for this TOAST attribute, create if necessary */
+	htabent = hash_search(pgStatToastActions, &toastattr,
+						  HASH_ENTER, &found);
+	if (!found)
+	{
+		MemSet(&htabent->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	/* update counters */
+	if (externalized)
+	{
+		htabent->t_counts.t_numexternalized++;
+	}
+	if (compressed)
+	{
+		htabent->t_counts.t_numcompressed++;
+		if (new_size)
+		{
+			htabent->t_counts.t_size_orig+=old_size;
+			if (new_size)
+			{
+				htabent->t_counts.t_numcompressionsuccess++;
+				htabent->t_counts.t_size_compressed+=new_size;
+			}
+		}
+	}
+	/* record time spent */
+	INSTR_TIME_ADD(htabent->t_counts.t_comp_time, time_spent);
+
+	/* indicate that we have something to send */
+	have_toast_stats = true;
+}
+
 
 /* ----------
  * pgstat_initstats() -
@@ -3028,6 +3175,35 @@ pgstat_fetch_stat_subworker_entry(Oid subid, Oid subrelid)
 	return wentry;
 }
 
+/* ----------
+ * pgstat_fetch_stat_toastentry() -
+ *
+ *	Support function for the SQL-callable pgstat* functions. Returns
+ *	the collected statistics for one TOAST attribute or NULL.
+ * ----------
+ */
+PgStat_StatToastEntry *
+pgstat_fetch_stat_toastentry(Oid rel_id, int attr)
+{
+	PgStat_StatDBEntry *dbentry;
+	PgStat_BackendAttrIdentifier toast_id = { rel_id, attr };
+	PgStat_StatToastEntry *toastentry = NULL;
+
+	/* load the stats file if needed */
+	backend_read_statsfile();
+
+	/* Lookup our database, then find the requested TOAST activity stats.  */
+	dbentry = pgstat_fetch_stat_dbentry(MyDatabaseId);
+	if (dbentry != NULL && dbentry->toastactivity != NULL)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &toast_id,
+														 HASH_FIND, NULL);
+	}
+
+	return toastentry;
+}
+
 /*
  * ---------
  * pgstat_fetch_stat_archiver() -
@@ -3708,6 +3884,10 @@ PgstatCollectorMain(int argc, char *argv[])
 					pgstat_recv_funcpurge(&msg.msg_funcpurge, len);
 					break;
 
+				case PGSTAT_MTYPE_TOASTSTAT:
+					pgstat_recv_toaststat(&msg.msg_toaststat, len);
+					break;
+
 				case PGSTAT_MTYPE_RECOVERYCONFLICT:
 					pgstat_recv_recoveryconflict(&msg.msg_recoveryconflict,
 												 len);
@@ -3852,6 +4032,14 @@ reset_dbentry_counters(PgStat_StatDBEntry *dbentry)
 									  PGSTAT_SUBWORKER_HASH_SIZE,
 									  &hash_ctl,
 									  HASH_ELEM | HASH_BLOBS);
+
+	hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+	hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+	dbentry->toastactivity = hash_create("Per-database TOAST",
+									 PGSTAT_TOAST_HASH_SIZE,
+									 &hash_ctl,
+									 HASH_ELEM | HASH_BLOBS);
+
 }
 
 /*
@@ -4059,8 +4247,8 @@ pgstat_write_statsfiles(bool permanent, bool allDbs)
 	while ((dbentry = (PgStat_StatDBEntry *) hash_seq_search(&hstat)) != NULL)
 	{
 		/*
-		 * Write out the table, function, and subscription-worker stats for
-		 * this DB into the appropriate per-DB stat file, if required.
+		 * Write out the table, function, TOAST and subscription-worker stats for this DB into the
+		 * appropriate per-DB stat file, if required.
 		 */
 		if (allDbs || pgstat_db_requested(dbentry->databaseid))
 		{
@@ -4175,9 +4363,11 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 	HASH_SEQ_STATUS tstat;
 	HASH_SEQ_STATUS fstat;
 	HASH_SEQ_STATUS sstat;
+	HASH_SEQ_STATUS ostat;
 	PgStat_StatTabEntry *tabentry;
 	PgStat_StatFuncEntry *funcentry;
 	PgStat_StatSubWorkerEntry *subwentry;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpout;
 	int32		format_id;
 	Oid			dbid = dbentry->databaseid;
@@ -4243,6 +4433,17 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 		(void) rc;				/* we'll check for error with ferror */
 	}
 
+	/*
+	 * Walk through the database's TOAST stats table.
+	 */
+	hash_seq_init(&ostat, dbentry->toastactivity);
+	while ((toastentry = (PgStat_StatToastEntry *) hash_seq_search(&ostat)) != NULL)
+	{
+		fputc('O', fpout);
+		rc = fwrite(toastentry, sizeof(PgStat_StatToastEntry), 1, fpout);
+		(void) rc;				/* we'll check for error with ferror */
+	}
+
 	/*
 	 * No more output to be done. Close the temp file and replace the old
 	 * pgstat.stat with it.  The ferror() check replaces testing for error
@@ -4483,6 +4684,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 				dbentry->tables = NULL;
 				dbentry->functions = NULL;
 				dbentry->subworkers = NULL;
+				dbentry->toastactivity = NULL;
 
 				/*
 				 * In the collector, disregard the timestamp we read from the
@@ -4528,6 +4730,14 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 												  &hash_ctl,
 												  HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
 
+				hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+				hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+				hash_ctl.hcxt = pgStatLocalContext;
+				dbentry->toastactivity = hash_create("Per-database toast information",
+												 PGSTAT_TOAST_HASH_SIZE,
+												 &hash_ctl,
+												 HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
+
 				/*
 				 * If requested, read the data from the database-specific
 				 * file.  Otherwise we just leave the hashtables empty.
@@ -4536,6 +4746,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 					pgstat_read_db_statsfile(dbentry->databaseid,
 											 dbentry->tables,
 											 dbentry->functions,
+											 dbentry->toastactivity,
 											 dbentry->subworkers,
 											 permanent);
 
@@ -4620,7 +4831,7 @@ done:
  * ----------
  */
 static void
-pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 						 HTAB *subworkerhash, bool permanent)
 {
 	PgStat_StatTabEntry *tabentry;
@@ -4629,6 +4840,8 @@ pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
 	PgStat_StatFuncEntry *funcentry;
 	PgStat_StatSubWorkerEntry subwbuf;
 	PgStat_StatSubWorkerEntry *subwentry;
+	PgStat_StatToastEntry toastbuf;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpin;
 	int32		format_id;
 	bool		found;
@@ -4777,6 +4990,32 @@ pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
 				memcpy(subwentry, &subwbuf, sizeof(subwbuf));
 				break;
 
+
+				/*
+				 * 'O'	A PgStat_StatToastEntry follows (tOast)
+				 */
+			case 'O':
+				if (fread(&toastbuf, 1, sizeof(PgStat_StatToastEntry),
+						  fpin) != sizeof(PgStat_StatToastEntry))
+				{
+					ereport(pgStatRunningInCollector ? LOG : WARNING,
+							(errmsg("corrupted statistics file \"%s\"",
+									statfile)));
+					goto done;
+				}
+
+				/*
+				 * Skip if TOAST data not wanted.
+				 */
+				if (toasthash == NULL)
+					break;
+
+				toastentry = (PgStat_StatToastEntry *) hash_search(toasthash,
+																 (void *) &toastbuf.t_id,
+																 HASH_ENTER, &found);
+				memcpy(toastentry, &toastbuf, sizeof(toastbuf));
+				break;
+
 				/*
 				 * 'E'	The EOF marker of a complete stats file.
 				 */
@@ -5452,6 +5691,8 @@ pgstat_recv_dropdb(PgStat_MsgDropdb *msg, int len)
 			hash_destroy(dbentry->functions);
 		if (dbentry->subworkers != NULL)
 			hash_destroy(dbentry->subworkers);
+		if (dbentry->toastactivity != NULL)
+			hash_destroy(dbentry->toastactivity);
 
 		if (hash_search(pgStatDBHash,
 						(void *) &dbid,
@@ -5491,10 +5732,12 @@ pgstat_recv_resetcounter(PgStat_MsgResetcounter *msg, int len)
 		hash_destroy(dbentry->functions);
 	if (dbentry->subworkers != NULL)
 		hash_destroy(dbentry->subworkers);
-
+	if (dbentry->toastactivity != NULL)
+		hash_destroy(dbentry->toastactivity);
 	dbentry->tables = NULL;
 	dbentry->functions = NULL;
 	dbentry->subworkers = NULL;
+	dbentry->toastactivity = NULL;
 
 	/*
 	 * Reset database-level stats, too.  This creates empty hash tables for
@@ -6152,6 +6395,60 @@ pgstat_recv_subscription_purge(PgStat_MsgSubscriptionPurge *msg, int len)
 	}
 }
 
+/* ----------
+ * pgstat_recv_toaststat() -
+ *
+ *	Count what the backend has done.
+ * ----------
+ */
+static void
+pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len)
+{
+	PgStat_ToastEntry *toastmsg = &(msg->m_entry[0]);
+	PgStat_StatDBEntry *dbentry;
+	PgStat_StatToastEntry *toastentry;
+	int			i;
+	bool		found;
+
+	dbentry = pgstat_get_db_entry(msg->m_databaseid, true);
+
+	/*
+	 * Process all TOAST entries in the message.
+	 */
+	for (i = 0; i < msg->m_nentries; i++, toastmsg++)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &(toastmsg->attr),
+														 HASH_ENTER, &found);
+
+		if (!found)
+		{
+			/*
+			 * If it's a new entry, initialize counters to the values
+			 * we just got.
+			 */
+			toastentry->t_numexternalized = toastmsg->t_numexternalized;
+			toastentry->t_numcompressed = toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess = toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_orig = toastmsg->t_size_orig;
+			toastentry->t_size_compressed = toastmsg->t_size_compressed;
+			toastentry->t_comp_time = toastmsg->t_comp_time;
+		}
+		else
+		{
+			/*
+			 * Otherwise add the values to the existing entry.
+			 */
+			toastentry->t_numexternalized += toastmsg->t_numexternalized;
+			toastentry->t_numcompressed += toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess += toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_orig += toastmsg->t_size_orig;
+			toastentry->t_size_compressed += toastmsg->t_size_compressed;
+			toastentry->t_comp_time += toastmsg->t_comp_time;
+		}
+	}
+}
+
 /* ----------
  * pgstat_recv_subworker_error() -
  *
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index f529c1561a..8b40c43626 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -410,6 +410,78 @@ pg_stat_get_function_self_time(PG_FUNCTION_ARGS)
 	PG_RETURN_FLOAT8(((double) funcentry->f_self_time) / 1000.0);
 }
 
+Datum
+pg_stat_get_toast_externalizations(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numexternalized);
+}
+
+Datum
+pg_stat_get_toast_compressions(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressed);
+}
+
+Datum
+pg_stat_get_toast_compressionsuccesses(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressionsuccess);
+}
+
+Datum
+pg_stat_get_toast_originalsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_orig);
+}
+
+Datum
+pg_stat_get_toast_compressedsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_compressed);
+}
+
+Datum
+pg_stat_get_toast_total_time(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_comp_time);
+}
+
 Datum
 pg_stat_get_backend_idset(PG_FUNCTION_ARGS)
 {
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index f9504d3aec..f7ff934d4e 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -1538,6 +1538,15 @@ static struct config_bool ConfigureNamesBool[] =
 		true,
 		NULL, NULL, NULL
 	},
+	{
+		{"track_toast", PGC_SUSET, STATS_COLLECTOR,
+			gettext_noop("Collects statistics on TOAST activity."),
+			NULL
+		},
+		&pgstat_track_toast,
+		false,
+		NULL, NULL, NULL
+	},
 	{
 		{"track_io_timing", PGC_SUSET, STATS_COLLECTOR,
 			gettext_noop("Collects timing statistics for database I/O activity."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index a1acd46b61..12f4bb1a38 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -607,6 +607,7 @@
 #track_io_timing = off
 #track_wal_io_timing = off
 #track_functions = none			# none, pl, all
+#track_toast = off
 #stats_temp_directory = 'pg_stat_tmp'
 
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 4d992dc224..22c34b96a6 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5668,6 +5668,31 @@
   proparallel => 'r', prorettype => 'float8', proargtypes => 'oid',
   prosrc => 'pg_stat_get_function_self_time' },
 
+{ oid => '9700', descr => 'statistics: number of TOAST externalizations',
+  proname => 'pg_stat_get_toast_externalizations', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_externalizations' },
+{ oid => '9701', descr => 'statistics: number of TOAST compressions',
+  proname => 'pg_stat_get_toast_compressions', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressions' },
+  { oid => '9702', descr => 'statistics: number of successful TOAST compressions',
+  proname => 'pg_stat_get_toast_compressionsuccesses', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressionsuccesses' },
+{ oid => '9703', descr => 'statistics: total original size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_originalsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_originalsizesum' },
+{ oid => '9704', descr => 'statistics: total compressed size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_compressedsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressedsizesum' },
+{ oid => '9705', descr => 'statistics: total time spend TOASTing data',
+  proname => 'pg_stat_get_toast_total_time', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_total_time' },
+
 { oid => '3037',
   descr => 'statistics: number of scans done for table/index in current transaction',
   proname => 'pg_stat_get_xact_numscans', provolatile => 'v',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5b51b58e5a..ff26aec404 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -82,10 +82,12 @@ typedef enum StatMsgType
 	PGSTAT_MTYPE_DEADLOCK,
 	PGSTAT_MTYPE_CHECKSUMFAILURE,
 	PGSTAT_MTYPE_REPLSLOT,
+	PGSTAT_MTYPE_CONNECTION,
 	PGSTAT_MTYPE_CONNECT,
 	PGSTAT_MTYPE_DISCONNECT,
 	PGSTAT_MTYPE_SUBSCRIPTIONPURGE,
 	PGSTAT_MTYPE_SUBWORKERERROR,
+	PGSTAT_MTYPE_TOASTSTAT,
 } StatMsgType;
 
 /* ----------
@@ -733,6 +735,80 @@ typedef struct PgStat_MsgDisconnect
 	SessionEndType m_cause;
 } PgStat_MsgDisconnect;
 
+/* ----------
+ * PgStat_BackendAttrIdentifier	Identifier for a single attribute/column (OID + attr)
+ * Used as a hashable identifier for (e.g.) TOAST columns
+ * ----------
+ */
+typedef struct PgStat_BackendAttrIdentifier
+{
+	Oid			relid;
+	int			attr;
+} PgStat_BackendAttrIdentifier;
+
+/* ----------
+ * PgStat_ToastCounts	The actual per-TOAST counts kept by a backend
+ *
+ * This struct should contain only actual event counters, because we memcmp
+ * it against zeroes to detect whether there are any counts to transmit.
+ *
+ * Note that the time counters are in instr_time format here.  We convert to
+ * microseconds in PgStat_Counter format when transmitting to the collector.
+ * ----------
+ */
+typedef struct PgStat_ToastCounts
+{
+	PgStat_Counter	t_numexternalized;
+	PgStat_Counter	t_numcompressed;
+	PgStat_Counter	t_numcompressionsuccess;
+	uint64		t_size_orig;
+	uint64		t_size_compressed;
+	instr_time	t_comp_time;
+} PgStat_ToastCounts;
+
+/* ----------
+ * PgStat_BackendToastEntry	Entry in backend's per-toast-attr hash table
+ * ----------
+ */
+typedef struct PgStat_BackendToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_ToastCounts 		t_counts;
+} PgStat_BackendToastEntry;
+
+/* ----------
+ * PgStat_ToastEntry			Per-TOAST-column info in a MsgFuncstat
+ * ----------
+ */
+typedef struct PgStat_ToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_Counter 			t_numexternalized;
+	PgStat_Counter 			t_numcompressed;
+	PgStat_Counter 			t_numcompressionsuccess;
+	uint64		   		t_size_orig;
+	uint64		   		t_size_compressed;
+	PgStat_Counter			t_comp_time;	/* time in microseconds */
+} PgStat_ToastEntry;
+
+/* ----------
+ * PgStat_MsgToaststat			Sent by the backend to report function
+ *								usage statistics.
+ * ----------
+ */
+#define PGSTAT_NUM_TOASTENTRIES	\
+	((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - sizeof(int))  \
+	 / sizeof(PgStat_ToastEntry))
+
+typedef struct PgStat_MsgToaststat
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+	int			m_nentries;
+	PgStat_ToastEntry m_entry[PGSTAT_NUM_TOASTENTRIES];
+} PgStat_MsgToaststat;
+
+
 /* ----------
  * PgStat_Msg					Union over all possible messages.
  * ----------
@@ -760,6 +836,7 @@ typedef union PgStat_Msg
 	PgStat_MsgSLRU msg_slru;
 	PgStat_MsgFuncstat msg_funcstat;
 	PgStat_MsgFuncpurge msg_funcpurge;
+	PgStat_MsgToaststat msg_toaststat;
 	PgStat_MsgRecoveryConflict msg_recoveryconflict;
 	PgStat_MsgDeadlock msg_deadlock;
 	PgStat_MsgTempFile msg_tempfile;
@@ -833,6 +910,7 @@ typedef struct PgStat_StatDBEntry
 	HTAB	   *tables;
 	HTAB	   *functions;
 	HTAB	   *subworkers;
+	HTAB	   *toastactivity;
 } PgStat_StatDBEntry;
 
 
@@ -1022,6 +1100,22 @@ typedef struct PgStat_StatSubWorkerEntry
 	char		last_error_message[PGSTAT_SUBWORKERERROR_MSGLEN];
 } PgStat_StatSubWorkerEntry;
 
+/* ----------
+ * PgStat_StatToastEntry			The collector's data per TOAST attribute
+ * ----------
+ */
+typedef struct PgStat_StatToastEntry
+{
+	PgStat_BackendAttrIdentifier t_id;
+	PgStat_Counter t_numexternalized;
+	PgStat_Counter t_numcompressed;
+	PgStat_Counter t_numcompressionsuccess;
+	uint64		   t_size_orig;
+	uint64		   t_size_compressed;
+	PgStat_Counter t_comp_time;	/* time in microseconds */
+} PgStat_StatToastEntry;
+
+
 /*
  * Working state needed to accumulate per-function-call timing statistics.
  */
@@ -1045,6 +1139,7 @@ typedef struct PgStat_FunctionCallUsage
  */
 extern PGDLLIMPORT bool pgstat_track_counts;
 extern PGDLLIMPORT int pgstat_track_functions;
+extern PGDLLIMPORT bool pgstat_track_toast;
 extern char *pgstat_stat_directory;
 extern char *pgstat_stat_tmpname;
 extern char *pgstat_stat_filename;
@@ -1196,12 +1291,22 @@ extern void pgstat_count_heap_delete(Relation rel);
 extern void pgstat_count_truncate(Relation rel);
 extern void pgstat_update_heap_dead_tuples(Relation rel, int delta);
 
+extern void pgstat_count_toast_insert(Relation rel, PgStat_Counter n);
+
 struct FunctionCallInfoBaseData;
 extern void pgstat_init_function_usage(struct FunctionCallInfoBaseData *fcinfo,
 									   PgStat_FunctionCallUsage *fcu);
 extern void pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu,
 									  bool finalize);
 
+extern void
+pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							instr_time start_time);
+
 extern void AtEOXact_PgStat(bool isCommit, bool parallel);
 extern void AtEOSubXact_PgStat(bool isCommit, int nestDepth);
 
@@ -1228,9 +1333,12 @@ extern PgStat_StatTabEntry *pgstat_fetch_stat_tabentry(Oid relid);
 extern PgStat_StatFuncEntry *pgstat_fetch_stat_funcentry(Oid funcid);
 extern PgStat_StatSubWorkerEntry *pgstat_fetch_stat_subworker_entry(Oid subid,
 																	Oid subrelid);
+extern PgStat_StatToastEntry *pgstat_fetch_stat_toastentry(Oid rel_id, int attr);
+extern PgStat_ArchiverStats *pgstat_fetch_stat_archiver(void);
 extern PgStat_ArchiverStats *pgstat_fetch_stat_archiver(void);
 extern PgStat_BgWriterStats *pgstat_fetch_stat_bgwriter(void);
 extern PgStat_CheckpointerStats *pgstat_fetch_stat_checkpointer(void);
+
 extern PgStat_GlobalStats *pgstat_fetch_global(void);
 extern PgStat_WalStats *pgstat_fetch_stat_wal(void);
 extern PgStat_SLRUStats *pgstat_fetch_slru(void);
diff --git a/src/test/modules/Makefile b/src/test/modules/Makefile
index dffc79b2d9..5ccc82b4b5 100644
--- a/src/test/modules/Makefile
+++ b/src/test/modules/Makefile
@@ -27,6 +27,7 @@ SUBDIRS = \
 		  test_regex \
 		  test_rls_hooks \
 		  test_shm_mq \
+		  track_toast \
 		  unsafe_tests \
 		  worker_spi
 
diff --git a/src/test/modules/track_toast/Makefile b/src/test/modules/track_toast/Makefile
new file mode 100644
index 0000000000..26089b3deb
--- /dev/null
+++ b/src/test/modules/track_toast/Makefile
@@ -0,0 +1,18 @@
+# src/test/modules/track_toast/Makefile
+
+REGRESS = track_toast
+REGRESS_OPTS = --temp-config=$(top_srcdir)/src/test/modules/track_toast/track_toast.conf
+# Disabled because these tests require "track_toast = on",
+# which typical installcheck users do not have (e.g. buildfarm clients).
+NO_INSTALLCHECK = 1
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/test/modules/track_toast
+top_builddir = ../../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
diff --git a/src/test/modules/track_toast/expected/track_toast.out b/src/test/modules/track_toast/expected/track_toast.out
new file mode 100644
index 0000000000..2887d580ab
--- /dev/null
+++ b/src/test/modules/track_toast/expected/track_toast.out
@@ -0,0 +1,55 @@
+SHOW track_toast;
+ track_toast 
+-------------
+ on
+(1 row)
+
+TABLE pg_stat_toast; -- view exists
+ schemaname | reloid | attnum | relname | attname | storagemethod | externalized | compressmethod | compressattempts | compresssuccesses | compressedsize | originalsize | total_time 
+------------+--------+--------+---------+---------+---------------+--------------+----------------+------------------+-------------------+----------------+--------------+------------
+(0 rows)
+
+CREATE TABLE toast_test (cola TEXT, colb TEXT COMPRESSION lz4, colc TEXT , cold TEXT, cole TEXT);
+ALTER TABLE toast_test ALTER colc SET STORAGE EXTERNAL;
+ALTER TABLE toast_test ALTER cold SET STORAGE MAIN;
+ALTER TABLE toast_test ALTER cole SET STORAGE PLAIN;
+INSERT INTO toast_test VALUES (repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100) );
+SELECT pg_sleep(1); -- give the stats collector some time to send the stats upstream
+ pg_sleep 
+----------
+ 
+(1 row)
+
+SELECT attname
+	,storagemethod
+	,externalized
+	,compressmethod
+	,compressattempts
+	,compresssuccesses
+	,compressedsize < originalsize AS compression_works
+	, total_time > 0 AS takes_time 
+FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY attname;
+ attname | storagemethod | externalized | compressmethod | compressattempts | compresssuccesses | compression_works | takes_time 
+---------+---------------+--------------+----------------+------------------+-------------------+-------------------+------------
+ cola    | x             |            1 |                |                1 |                 1 | t                 | t
+ colb    | x             |            1 | l              |                1 |                 1 | t                 | t
+ colc    | e             |            1 |                |                0 |                 0 | f                 | t
+ cold    | m             |            0 |                |                1 |                 1 | t                 | t
+(4 rows)
+
+SELECT storagemethod,compressmethod FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY total_time DESC;
+ storagemethod | compressmethod 
+---------------+----------------
+ e             | 
+ x             | 
+ x             | l
+ m             | 
+(4 rows)
+
+DROP TABLE toast_test;
+SELECT count(*) FROM pg_stat_toast WHERE relname = 'toast_test';
+ count 
+-------
+     0
+(1 row)
+
diff --git a/src/test/modules/track_toast/sql/track_toast.sql b/src/test/modules/track_toast/sql/track_toast.sql
new file mode 100644
index 0000000000..4c3b4b996b
--- /dev/null
+++ b/src/test/modules/track_toast/sql/track_toast.sql
@@ -0,0 +1,20 @@
+SHOW track_toast;
+TABLE pg_stat_toast; -- view exists
+CREATE TABLE toast_test (cola TEXT, colb TEXT COMPRESSION lz4, colc TEXT , cold TEXT, cole TEXT);
+ALTER TABLE toast_test ALTER colc SET STORAGE EXTERNAL;
+ALTER TABLE toast_test ALTER cold SET STORAGE MAIN;
+ALTER TABLE toast_test ALTER cole SET STORAGE PLAIN;
+INSERT INTO toast_test VALUES (repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100) );
+SELECT pg_sleep(1); -- give the stats collector some time to send the stats upstream
+SELECT attname
+	,storagemethod
+	,externalized
+	,compressmethod
+	,compressattempts
+	,compresssuccesses
+	,compressedsize < originalsize AS compression_works
+	, total_time > 0 AS takes_time 
+FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY attname;
+SELECT storagemethod,compressmethod FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY total_time DESC;
+DROP TABLE toast_test;
+SELECT count(*) FROM pg_stat_toast WHERE relname = 'toast_test';
diff --git a/src/test/modules/track_toast/track_toast.conf b/src/test/modules/track_toast/track_toast.conf
new file mode 100644
index 0000000000..191f40a762
--- /dev/null
+++ b/src/test/modules/track_toast/track_toast.conf
@@ -0,0 +1 @@
+track_toast = on
\ No newline at end of file
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index b58b062b10..2b49bebcb8 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -2147,6 +2147,23 @@ pg_stat_sys_tables| SELECT pg_stat_all_tables.relid,
     pg_stat_all_tables.autoanalyze_count
    FROM pg_stat_all_tables
   WHERE ((pg_stat_all_tables.schemaname = ANY (ARRAY['pg_catalog'::name, 'information_schema'::name])) OR (pg_stat_all_tables.schemaname ~ '^pg_toast'::text));
+pg_stat_toast| SELECT n.nspname AS schemaname,
+    a.attrelid AS reloid,
+    a.attnum,
+    c.relname,
+    a.attname,
+    a.attstorage AS storagemethod,
+    pg_stat_get_toast_externalizations(a.attrelid, (a.attnum)::integer) AS externalized,
+    a.attcompression AS compressmethod,
+    pg_stat_get_toast_compressions(a.attrelid, (a.attnum)::integer) AS compressattempts,
+    pg_stat_get_toast_compressionsuccesses(a.attrelid, (a.attnum)::integer) AS compresssuccesses,
+    pg_stat_get_toast_compressedsizesum(a.attrelid, (a.attnum)::integer) AS compressedsize,
+    pg_stat_get_toast_originalsizesum(a.attrelid, (a.attnum)::integer) AS originalsize,
+    pg_stat_get_toast_total_time(a.attrelid, (a.attnum)::integer) AS total_time
+   FROM ((pg_attribute a
+     JOIN pg_class c ON ((c.oid = a.attrelid)))
+     LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace)))
+  WHERE (pg_stat_get_toast_externalizations(a.attrelid, (a.attnum)::integer) IS NOT NULL);
 pg_stat_user_functions| SELECT p.oid AS funcid,
     n.nspname AS schemaname,
     p.proname AS funcname,

From 560cfb4082804709d952b3f741b505025f400f97 Mon Sep 17 00:00:00 2001
From: "Gunnar \"Nick\" Bluth" <gunnar.bluth@pro-open.de>
Date: Mon, 3 Jan 2022 16:18:36 +0100
Subject: [PATCH] pg_stat_toast_v0.4

---
 doc/src/sgml/config.sgml                      |  26 ++
 doc/src/sgml/monitoring.sgml                  | 163 +++++++++
 doc/src/sgml/storage.sgml                     |  12 +-
 src/backend/access/table/toast_helper.c       |  24 ++
 src/backend/catalog/system_views.sql          |  20 ++
 src/backend/postmaster/pgstat.c               | 309 +++++++++++++++++-
 src/backend/utils/adt/pgstatfuncs.c           |  72 ++++
 src/backend/utils/misc/guc.c                  |   9 +
 src/backend/utils/misc/postgresql.conf.sample |   1 +
 src/include/catalog/pg_proc.dat               |  25 ++
 src/include/pgstat.h                          | 108 ++++++
 src/test/modules/Makefile                     |   1 +
 src/test/modules/track_toast/Makefile         |  18 +
 .../track_toast/expected/track_toast.out      |  55 ++++
 .../modules/track_toast/sql/track_toast.sql   |  20 ++
 src/test/modules/track_toast/track_toast.conf |   1 +
 src/test/regress/expected/rules.out           |  17 +
 17 files changed, 874 insertions(+), 7 deletions(-)
 create mode 100644 src/test/modules/track_toast/Makefile
 create mode 100644 src/test/modules/track_toast/expected/track_toast.out
 create mode 100644 src/test/modules/track_toast/sql/track_toast.sql
 create mode 100644 src/test/modules/track_toast/track_toast.conf

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index afbb6c35e3..fa40befc16 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -7668,6 +7668,32 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv;
       </listitem>
      </varlistentry>
 
+     <varlistentry id="guc-track-toast" xreflabel="track_toast">
+      <term><varname>track_toast</varname> (<type>boolean</type>)
+      <indexterm>
+       <primary><varname>track_toast</varname> configuration parameter</primary>
+      </indexterm>
+      </term>
+      <listitem>
+       <para>
+        Enables tracking of <link linkend="storage-toast">TOAST</link> activities.
+        Compressions and externalizations are tracked.
+        The default is <literal>off</literal>.
+        Only superusers can change this setting.
+       </para>
+
+       <note>
+        <para>
+        Be aware that this feature, depending on the amount of TOASTable columns in
+        your databases, may significantly increase the size of the statistics files
+        and the workload of the statistics collector. It is recommended to only
+        temporarily activate this to assess the right compression and storage method
+        for (a) column(s).
+        </para>
+       </note>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="guc-stats-temp-directory" xreflabel="stats_temp_directory">
       <term><varname>stats_temp_directory</varname> (<type>string</type>)
       <indexterm>
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 62f2a3332b..32d7818096 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -610,6 +610,17 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
       yet included in <structname>pg_stat_user_functions</structname>).</entry>
      </row>
 
+     <row>
+      <entry><structname>pg_stat_toast</structname><indexterm><primary>pg_stat_toast</primary></indexterm></entry>
+      <entry>
+       One row for each column that has ever been TOASTed (compressed and/or externalized).
+       Showing the number of externalizations, compression attempts / successes, compressed and
+       uncompressed sizes etc.
+       <link linkend="monitoring-pg-stat-toast-view">
+       <structname>pg_stat_toast</structname></link> for details.
+      </entry>
+     </row>
+
      <row>
       <entry><structname>pg_stat_slru</structname><indexterm><primary>pg_stat_slru</primary></indexterm></entry>
       <entry>One row per SLRU, showing statistics of operations. See
@@ -4969,6 +4980,158 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
 
  </sect2>
 
+ <sect2 id="monitoring-pg-stat-toast-view">
+  <title><structname>pg_stat_toast</structname></title>
+
+  <indexterm>
+   <primary>pg_stat_toast</primary>
+  </indexterm>
+
+  <para>
+   The <structname>pg_stat_toast</structname> view will contain
+   one row for each column of variable size that has been TOASTed since 
+   the last statistics reset. The <xref linkend="guc-track-toast"/> parameter
+   controls whether TOAST activities are tracked or not.
+  </para>
+
+  <table id="pg-stat-toast-view" xreflabel="pg_stat_toast">
+   <title><structname>pg_stat_toast</structname> View</title>
+   <tgroup cols="1">
+    <thead>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       Column Type
+      </para>
+      <para>
+       Description
+      </para></entry>
+     </row>
+    </thead>
+
+    <tbody>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>schemaname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the schema the relation is in
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>reloid</structfield> <type>oid</type>
+      </para>
+      <para>
+       OID of the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>attnum</structfield> <type>int</type>
+      </para>
+      <para>
+       Attribute (column) number in the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>relname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>attname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the attribute (column)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>storagemethod</structfield> <type>char</type>
+      </para>
+      <para>
+       Storage method of the attribute
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>externalized</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times this attribute was externalized (pushed to TOAST relation)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressmethod</structfield> <type>char</type>
+      </para>
+      <para>
+       Compression method of the attribute (empty means default)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressattempts</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times this attribute was compressed
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compresssuccesses</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times the compression was successful (gained a size reduction)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressedsize</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total size of all compressed datums
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>originalsize</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total size of all compressed datums before compression
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>total_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Total time spent TOASTing this attribute, in microseconds.
+      </para></entry>
+     </row>
+
+    </tbody>
+   </tgroup>
+  </table>
+
+ </sect2>
+
  <sect2 id="monitoring-pg-stat-slru-view">
   <title><structname>pg_stat_slru</structname></title>
 
diff --git a/doc/src/sgml/storage.sgml b/doc/src/sgml/storage.sgml
index 7136bbe7a3..2a47922573 100644
--- a/doc/src/sgml/storage.sgml
+++ b/doc/src/sgml/storage.sgml
@@ -517,6 +517,15 @@ pages). There was no run time difference compared to an un-<acronym>TOAST</acron
 comparison table, in which all the HTML pages were cut down to 7 kB to fit.
 </para>
 
+<para>
+When you enable <xref linkend="guc-track-toast"/>, the system view
+<link linkend="monitoring-pg-stat-toast-view"><structname>pg_stat_toast</structname>
+</link> provides details on the number and effect of compression attempts,
+number of externalizations and some more useful information that enables you
+to decide if a different storage method and/or compression method would suite a
+column better.
+</para>
+
 </sect2>
 
 <sect2 id="storage-toast-inmemory">
@@ -1068,7 +1077,8 @@ data. Empty in ordinary tables.</entry>
   <type>struct varlena</type>, which includes the total length of the stored
   value and some flag bits.  Depending on the flags, the data can be either
   inline or in a <acronym>TOAST</acronym> table;
-  it might be compressed, too (see <xref linkend="storage-toast"/>).
+  it might be compressed, too (see <xref linkend="storage-toast"/> and 
+  <xref linkend="monitoring-pg-stat-toast-view"/>).
 
  </para>
  </sect2>
diff --git a/src/backend/access/table/toast_helper.c b/src/backend/access/table/toast_helper.c
index 013236b73d..f6b06e3329 100644
--- a/src/backend/access/table/toast_helper.c
+++ b/src/backend/access/table/toast_helper.c
@@ -19,6 +19,7 @@
 #include "access/toast_helper.h"
 #include "access/toast_internals.h"
 #include "catalog/pg_type_d.h"
+#include "pgstat.h"
 
 
 /*
@@ -229,7 +230,9 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 	Datum	   *value = &ttc->ttc_values[attribute];
 	Datum		new_value;
 	ToastAttrInfo *attr = &ttc->ttc_attr[attribute];
+	instr_time	start_time;
 
+	INSTR_TIME_SET_CURRENT(start_time);
 	new_value = toast_compress_datum(*value, attr->tai_compression);
 
 	if (DatumGetPointer(new_value) != NULL)
@@ -239,6 +242,12 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 			pfree(DatumGetPointer(*value));
 		*value = new_value;
 		attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
+		pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							attr->tai_size,
+							VARSIZE(DatumGetPointer(*value)),
+							start_time);
 		attr->tai_size = VARSIZE(DatumGetPointer(*value));
 		ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
 	}
@@ -246,6 +255,12 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 	{
 		/* incompressible, ignore on subsequent compression passes */
 		attr->tai_colflags |= TOASTCOL_INCOMPRESSIBLE;
+		pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							0,
+							0,
+							start_time);
 	}
 }
 
@@ -258,6 +273,9 @@ toast_tuple_externalize(ToastTupleContext *ttc, int attribute, int options)
 	Datum	   *value = &ttc->ttc_values[attribute];
 	Datum		old_value = *value;
 	ToastAttrInfo *attr = &ttc->ttc_attr[attribute];
+	instr_time	start_time;
+
+	INSTR_TIME_SET_CURRENT(start_time);
 
 	attr->tai_colflags |= TOASTCOL_IGNORE;
 	*value = toast_save_datum(ttc->ttc_rel, old_value, attr->tai_oldexternal,
@@ -266,6 +284,12 @@ toast_tuple_externalize(ToastTupleContext *ttc, int attribute, int options)
 		pfree(DatumGetPointer(old_value));
 	attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
 	ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
+	pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							true,
+							false,
+							0,
+							0,
+							start_time);
 }
 
 /*
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 61b515cdb8..3de3025488 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -1039,6 +1039,26 @@ CREATE VIEW pg_stat_user_functions AS
     WHERE P.prolang != 12  -- fast check to eliminate built-in functions
           AND pg_stat_get_function_calls(P.oid) IS NOT NULL;
 
+
+CREATE OR REPLACE VIEW pg_stat_toast AS
+ SELECT 
+    n.nspname AS schemaname,
+    a.attrelid AS reloid,
+    a.attnum AS attnum,
+    c.relname AS relname,
+    a.attname AS attname,
+    attstorage AS storagemethod,
+    pg_stat_get_toast_externalizations(a.attrelid,a.attnum) AS externalized,
+    attcompression AS compressmethod,
+    pg_stat_get_toast_compressions(a.attrelid,a.attnum) AS compressattempts,
+    pg_stat_get_toast_compressionsuccesses(a.attrelid,a.attnum) AS compresssuccesses,
+    pg_stat_get_toast_compressedsizesum(a.attrelid,a.attnum) AS compressedsize,
+    pg_stat_get_toast_originalsizesum(a.attrelid,a.attnum) AS originalsize,
+    pg_stat_get_toast_total_time(a.attrelid,a.attnum) AS total_time
+   FROM pg_attribute a
+   JOIN pg_class c ON c.oid = a.attrelid
+   LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
+  WHERE pg_stat_get_toast_externalizations(a.attrelid,a.attnum) IS NOT NULL;
 CREATE VIEW pg_stat_xact_user_functions AS
     SELECT
             P.oid AS funcid,
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 7264d2c727..c4ce619257 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -106,6 +106,7 @@
 #define PGSTAT_DB_HASH_SIZE		16
 #define PGSTAT_TAB_HASH_SIZE	512
 #define PGSTAT_FUNCTION_HASH_SIZE	512
+#define PGSTAT_TOAST_HASH_SIZE	64
 #define PGSTAT_SUBWORKER_HASH_SIZE	32
 #define PGSTAT_REPLSLOT_HASH_SIZE	32
 
@@ -116,6 +117,7 @@
  */
 bool		pgstat_track_counts = false;
 int			pgstat_track_functions = TRACK_FUNC_OFF;
+bool		pgstat_track_toast = false;
 
 /* ----------
  * Built from GUC parameter
@@ -228,6 +230,19 @@ static HTAB *pgStatFunctions = NULL;
  */
 static bool have_function_stats = false;
 
+/*
+ * Backends store per-toast-column info that's waiting to be sent to the collector
+ * in this hash table (indexed by column's PgStat_BackendAttrIdentifier).
+ */
+static HTAB *pgStatToastActions = NULL;
+
+
+/*
+ * Indicates if backend has some toast stats that it hasn't yet
+ * sent to the collector.
+ */
+static bool have_toast_stats = false;
+
 /*
  * Tuple insertion/deletion counts for an open transaction can't be propagated
  * into PgStat_TableStatus counters until we know if it is going to commit
@@ -328,7 +343,7 @@ static PgStat_StatSubWorkerEntry *pgstat_get_subworker_entry(PgStat_StatDBEntry
 static void pgstat_write_statsfiles(bool permanent, bool allDbs);
 static void pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent);
 static HTAB *pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep);
-static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 									 HTAB *subworkerhash, bool permanent);
 static void backend_read_statsfile(void);
 
@@ -340,6 +355,7 @@ static void pgstat_reset_replslot(PgStat_StatReplSlotEntry *slotstats, Timestamp
 
 static void pgstat_send_tabstat(PgStat_MsgTabstat *tsmsg, TimestampTz now);
 static void pgstat_send_funcstats(void);
+static void pgstat_send_toaststats(void);
 static void pgstat_send_slru(void);
 static void pgstat_send_subscription_purge(PgStat_MsgSubscriptionPurge *msg);
 static HTAB *pgstat_collect_oids(Oid catalogid, AttrNumber anum_oid);
@@ -373,6 +389,7 @@ static void pgstat_recv_wal(PgStat_MsgWal *msg, int len);
 static void pgstat_recv_slru(PgStat_MsgSLRU *msg, int len);
 static void pgstat_recv_funcstat(PgStat_MsgFuncstat *msg, int len);
 static void pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len);
+static void pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len);
 static void pgstat_recv_recoveryconflict(PgStat_MsgRecoveryConflict *msg, int len);
 static void pgstat_recv_deadlock(PgStat_MsgDeadlock *msg, int len);
 static void pgstat_recv_checksum_failure(PgStat_MsgChecksumFailure *msg, int len);
@@ -891,7 +908,7 @@ pgstat_report_stat(bool disconnect)
 		pgStatXactCommit == 0 && pgStatXactRollback == 0 &&
 		pgWalUsage.wal_records == prevWalUsage.wal_records &&
 		WalStats.m_wal_write == 0 && WalStats.m_wal_sync == 0 &&
-		!have_function_stats && !disconnect)
+		!have_function_stats && !have_toast_stats && !disconnect)
 		return;
 
 	/*
@@ -983,6 +1000,9 @@ pgstat_report_stat(bool disconnect)
 	/* Now, send function statistics */
 	pgstat_send_funcstats();
 
+	/* Now, send TOAST statistics */
+	pgstat_send_toaststats();
+
 	/* Send WAL statistics */
 	pgstat_send_wal(true);
 
@@ -1116,6 +1136,64 @@ pgstat_send_funcstats(void)
 	have_function_stats = false;
 }
 
+/*
+ * Subroutine for pgstat_report_stat: populate and send a toast stat message
+ */
+static void
+pgstat_send_toaststats(void)
+{
+	/* we assume this inits to all zeroes: */
+	static const PgStat_ToastCounts all_zeroes;
+
+	PgStat_MsgToaststat msg;
+	PgStat_BackendToastEntry *entry;
+	HASH_SEQ_STATUS tstat;
+
+	if (pgStatToastActions == NULL)
+		return;
+
+	pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_TOASTSTAT);
+	msg.m_databaseid = MyDatabaseId;
+	msg.m_nentries = 0;
+
+	hash_seq_init(&tstat, pgStatToastActions);
+	while ((entry = (PgStat_BackendToastEntry *) hash_seq_search(&tstat)) != NULL)
+	{
+		PgStat_ToastEntry *m_ent;
+
+		/* Skip it if no counts accumulated since last time */
+		if (memcmp(&entry->t_counts, &all_zeroes,
+				   sizeof(PgStat_ToastCounts)) == 0)
+			continue;
+
+		/* need to convert format of time accumulators */
+		m_ent = &msg.m_entry[msg.m_nentries];
+		m_ent->attr = entry->attr;
+		m_ent->t_numexternalized = entry->t_counts.t_numexternalized;
+		m_ent->t_numcompressed = entry->t_counts.t_numcompressed;
+		m_ent->t_numcompressionsuccess = entry->t_counts.t_numcompressionsuccess;
+		m_ent->t_size_orig = entry->t_counts.t_size_orig;
+		m_ent->t_size_compressed = entry->t_counts.t_size_compressed;
+		m_ent->t_comp_time = INSTR_TIME_GET_MICROSEC(entry->t_counts.t_comp_time);
+
+		if (++msg.m_nentries >= PGSTAT_NUM_TOASTENTRIES)
+		{
+			pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+						msg.m_nentries * sizeof(PgStat_ToastEntry));
+			msg.m_nentries = 0;
+		}
+
+		/* reset the entry's counts */
+		MemSet(&entry->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	if (msg.m_nentries > 0)
+		pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+					msg.m_nentries * sizeof(PgStat_ToastEntry));
+
+	have_toast_stats = false;
+}
+
 
 /* ----------
  * pgstat_vacuum_stat() -
@@ -2151,6 +2229,75 @@ pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu, bool finalize)
 	have_function_stats = true;
 }
 
+/*
+ * Report TOAST activity
+ * Called by toast_helper functions.
+ */
+void
+pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							instr_time start_time)
+{
+	PgStat_BackendAttrIdentifier toastattr = { relid, attr };
+	PgStat_BackendToastEntry *htabent;
+	instr_time	time_spent;
+	bool		found;
+
+	if (pgStatSock == PGINVALID_SOCKET || !pgstat_track_toast)
+		return;
+
+	INSTR_TIME_SET_CURRENT(time_spent);
+	INSTR_TIME_SUBTRACT(time_spent, start_time);
+
+	if (!pgStatToastActions)
+	{
+		/* First time through - initialize toast stat table */
+		HASHCTL		hash_ctl;
+
+		hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+		hash_ctl.entrysize = sizeof(PgStat_BackendToastEntry);
+		pgStatToastActions = hash_create("TOAST stat entries",
+									  PGSTAT_TOAST_HASH_SIZE,
+									  &hash_ctl,
+									  HASH_ELEM | HASH_BLOBS);
+	}
+
+	/* Get the stats entry for this TOAST attribute, create if necessary */
+	htabent = hash_search(pgStatToastActions, &toastattr,
+						  HASH_ENTER, &found);
+	if (!found)
+	{
+		MemSet(&htabent->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	/* update counters */
+	if (externalized)
+	{
+		htabent->t_counts.t_numexternalized++;
+	}
+	if (compressed)
+	{
+		htabent->t_counts.t_numcompressed++;
+		if (new_size)
+		{
+			htabent->t_counts.t_size_orig+=old_size;
+			if (new_size)
+			{
+				htabent->t_counts.t_numcompressionsuccess++;
+				htabent->t_counts.t_size_compressed+=new_size;
+			}
+		}
+	}
+	/* record time spent */
+	INSTR_TIME_ADD(htabent->t_counts.t_comp_time, time_spent);
+
+	/* indicate that we have something to send */
+	have_toast_stats = true;
+}
+
 
 /* ----------
  * pgstat_initstats() -
@@ -3028,6 +3175,35 @@ pgstat_fetch_stat_subworker_entry(Oid subid, Oid subrelid)
 	return wentry;
 }
 
+/* ----------
+ * pgstat_fetch_stat_toastentry() -
+ *
+ *	Support function for the SQL-callable pgstat* functions. Returns
+ *	the collected statistics for one TOAST attribute or NULL.
+ * ----------
+ */
+PgStat_StatToastEntry *
+pgstat_fetch_stat_toastentry(Oid rel_id, int attr)
+{
+	PgStat_StatDBEntry *dbentry;
+	PgStat_BackendAttrIdentifier toast_id = { rel_id, attr };
+	PgStat_StatToastEntry *toastentry = NULL;
+
+	/* load the stats file if needed */
+	backend_read_statsfile();
+
+	/* Lookup our database, then find the requested TOAST activity stats.  */
+	dbentry = pgstat_fetch_stat_dbentry(MyDatabaseId);
+	if (dbentry != NULL && dbentry->toastactivity != NULL)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &toast_id,
+														 HASH_FIND, NULL);
+	}
+
+	return toastentry;
+}
+
 /*
  * ---------
  * pgstat_fetch_stat_archiver() -
@@ -3708,6 +3884,10 @@ PgstatCollectorMain(int argc, char *argv[])
 					pgstat_recv_funcpurge(&msg.msg_funcpurge, len);
 					break;
 
+				case PGSTAT_MTYPE_TOASTSTAT:
+					pgstat_recv_toaststat(&msg.msg_toaststat, len);
+					break;
+
 				case PGSTAT_MTYPE_RECOVERYCONFLICT:
 					pgstat_recv_recoveryconflict(&msg.msg_recoveryconflict,
 												 len);
@@ -3852,6 +4032,14 @@ reset_dbentry_counters(PgStat_StatDBEntry *dbentry)
 									  PGSTAT_SUBWORKER_HASH_SIZE,
 									  &hash_ctl,
 									  HASH_ELEM | HASH_BLOBS);
+
+	hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+	hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+	dbentry->toastactivity = hash_create("Per-database TOAST",
+									 PGSTAT_TOAST_HASH_SIZE,
+									 &hash_ctl,
+									 HASH_ELEM | HASH_BLOBS);
+
 }
 
 /*
@@ -4059,8 +4247,8 @@ pgstat_write_statsfiles(bool permanent, bool allDbs)
 	while ((dbentry = (PgStat_StatDBEntry *) hash_seq_search(&hstat)) != NULL)
 	{
 		/*
-		 * Write out the table, function, and subscription-worker stats for
-		 * this DB into the appropriate per-DB stat file, if required.
+		 * Write out the table, function, TOAST and subscription-worker stats for this DB into the
+		 * appropriate per-DB stat file, if required.
 		 */
 		if (allDbs || pgstat_db_requested(dbentry->databaseid))
 		{
@@ -4175,9 +4363,11 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 	HASH_SEQ_STATUS tstat;
 	HASH_SEQ_STATUS fstat;
 	HASH_SEQ_STATUS sstat;
+	HASH_SEQ_STATUS ostat;
 	PgStat_StatTabEntry *tabentry;
 	PgStat_StatFuncEntry *funcentry;
 	PgStat_StatSubWorkerEntry *subwentry;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpout;
 	int32		format_id;
 	Oid			dbid = dbentry->databaseid;
@@ -4243,6 +4433,17 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 		(void) rc;				/* we'll check for error with ferror */
 	}
 
+	/*
+	 * Walk through the database's TOAST stats table.
+	 */
+	hash_seq_init(&ostat, dbentry->toastactivity);
+	while ((toastentry = (PgStat_StatToastEntry *) hash_seq_search(&ostat)) != NULL)
+	{
+		fputc('O', fpout);
+		rc = fwrite(toastentry, sizeof(PgStat_StatToastEntry), 1, fpout);
+		(void) rc;				/* we'll check for error with ferror */
+	}
+
 	/*
 	 * No more output to be done. Close the temp file and replace the old
 	 * pgstat.stat with it.  The ferror() check replaces testing for error
@@ -4483,6 +4684,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 				dbentry->tables = NULL;
 				dbentry->functions = NULL;
 				dbentry->subworkers = NULL;
+				dbentry->toastactivity = NULL;
 
 				/*
 				 * In the collector, disregard the timestamp we read from the
@@ -4528,6 +4730,14 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 												  &hash_ctl,
 												  HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
 
+				hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+				hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+				hash_ctl.hcxt = pgStatLocalContext;
+				dbentry->toastactivity = hash_create("Per-database toast information",
+												 PGSTAT_TOAST_HASH_SIZE,
+												 &hash_ctl,
+												 HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
+
 				/*
 				 * If requested, read the data from the database-specific
 				 * file.  Otherwise we just leave the hashtables empty.
@@ -4536,6 +4746,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 					pgstat_read_db_statsfile(dbentry->databaseid,
 											 dbentry->tables,
 											 dbentry->functions,
+											 dbentry->toastactivity,
 											 dbentry->subworkers,
 											 permanent);
 
@@ -4620,7 +4831,7 @@ done:
  * ----------
  */
 static void
-pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 						 HTAB *subworkerhash, bool permanent)
 {
 	PgStat_StatTabEntry *tabentry;
@@ -4629,6 +4840,8 @@ pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
 	PgStat_StatFuncEntry *funcentry;
 	PgStat_StatSubWorkerEntry subwbuf;
 	PgStat_StatSubWorkerEntry *subwentry;
+	PgStat_StatToastEntry toastbuf;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpin;
 	int32		format_id;
 	bool		found;
@@ -4777,6 +4990,32 @@ pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
 				memcpy(subwentry, &subwbuf, sizeof(subwbuf));
 				break;
 
+
+				/*
+				 * 'O'	A PgStat_StatToastEntry follows (tOast)
+				 */
+			case 'O':
+				if (fread(&toastbuf, 1, sizeof(PgStat_StatToastEntry),
+						  fpin) != sizeof(PgStat_StatToastEntry))
+				{
+					ereport(pgStatRunningInCollector ? LOG : WARNING,
+							(errmsg("corrupted statistics file \"%s\"",
+									statfile)));
+					goto done;
+				}
+
+				/*
+				 * Skip if TOAST data not wanted.
+				 */
+				if (toasthash == NULL)
+					break;
+
+				toastentry = (PgStat_StatToastEntry *) hash_search(toasthash,
+																 (void *) &toastbuf.t_id,
+																 HASH_ENTER, &found);
+				memcpy(toastentry, &toastbuf, sizeof(toastbuf));
+				break;
+
 				/*
 				 * 'E'	The EOF marker of a complete stats file.
 				 */
@@ -5452,6 +5691,8 @@ pgstat_recv_dropdb(PgStat_MsgDropdb *msg, int len)
 			hash_destroy(dbentry->functions);
 		if (dbentry->subworkers != NULL)
 			hash_destroy(dbentry->subworkers);
+		if (dbentry->toastactivity != NULL)
+			hash_destroy(dbentry->toastactivity);
 
 		if (hash_search(pgStatDBHash,
 						(void *) &dbid,
@@ -5491,10 +5732,12 @@ pgstat_recv_resetcounter(PgStat_MsgResetcounter *msg, int len)
 		hash_destroy(dbentry->functions);
 	if (dbentry->subworkers != NULL)
 		hash_destroy(dbentry->subworkers);
-
+	if (dbentry->toastactivity != NULL)
+		hash_destroy(dbentry->toastactivity);
 	dbentry->tables = NULL;
 	dbentry->functions = NULL;
 	dbentry->subworkers = NULL;
+	dbentry->toastactivity = NULL;
 
 	/*
 	 * Reset database-level stats, too.  This creates empty hash tables for
@@ -6152,6 +6395,60 @@ pgstat_recv_subscription_purge(PgStat_MsgSubscriptionPurge *msg, int len)
 	}
 }
 
+/* ----------
+ * pgstat_recv_toaststat() -
+ *
+ *	Count what the backend has done.
+ * ----------
+ */
+static void
+pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len)
+{
+	PgStat_ToastEntry *toastmsg = &(msg->m_entry[0]);
+	PgStat_StatDBEntry *dbentry;
+	PgStat_StatToastEntry *toastentry;
+	int			i;
+	bool		found;
+
+	dbentry = pgstat_get_db_entry(msg->m_databaseid, true);
+
+	/*
+	 * Process all TOAST entries in the message.
+	 */
+	for (i = 0; i < msg->m_nentries; i++, toastmsg++)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &(toastmsg->attr),
+														 HASH_ENTER, &found);
+
+		if (!found)
+		{
+			/*
+			 * If it's a new entry, initialize counters to the values
+			 * we just got.
+			 */
+			toastentry->t_numexternalized = toastmsg->t_numexternalized;
+			toastentry->t_numcompressed = toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess = toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_orig = toastmsg->t_size_orig;
+			toastentry->t_size_compressed = toastmsg->t_size_compressed;
+			toastentry->t_comp_time = toastmsg->t_comp_time;
+		}
+		else
+		{
+			/*
+			 * Otherwise add the values to the existing entry.
+			 */
+			toastentry->t_numexternalized += toastmsg->t_numexternalized;
+			toastentry->t_numcompressed += toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess += toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_orig += toastmsg->t_size_orig;
+			toastentry->t_size_compressed += toastmsg->t_size_compressed;
+			toastentry->t_comp_time += toastmsg->t_comp_time;
+		}
+	}
+}
+
 /* ----------
  * pgstat_recv_subworker_error() -
  *
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index f529c1561a..8b40c43626 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -410,6 +410,78 @@ pg_stat_get_function_self_time(PG_FUNCTION_ARGS)
 	PG_RETURN_FLOAT8(((double) funcentry->f_self_time) / 1000.0);
 }
 
+Datum
+pg_stat_get_toast_externalizations(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numexternalized);
+}
+
+Datum
+pg_stat_get_toast_compressions(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressed);
+}
+
+Datum
+pg_stat_get_toast_compressionsuccesses(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressionsuccess);
+}
+
+Datum
+pg_stat_get_toast_originalsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_orig);
+}
+
+Datum
+pg_stat_get_toast_compressedsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_compressed);
+}
+
+Datum
+pg_stat_get_toast_total_time(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_comp_time);
+}
+
 Datum
 pg_stat_get_backend_idset(PG_FUNCTION_ARGS)
 {
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index f9504d3aec..f7ff934d4e 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -1538,6 +1538,15 @@ static struct config_bool ConfigureNamesBool[] =
 		true,
 		NULL, NULL, NULL
 	},
+	{
+		{"track_toast", PGC_SUSET, STATS_COLLECTOR,
+			gettext_noop("Collects statistics on TOAST activity."),
+			NULL
+		},
+		&pgstat_track_toast,
+		false,
+		NULL, NULL, NULL
+	},
 	{
 		{"track_io_timing", PGC_SUSET, STATS_COLLECTOR,
 			gettext_noop("Collects timing statistics for database I/O activity."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index a1acd46b61..12f4bb1a38 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -607,6 +607,7 @@
 #track_io_timing = off
 #track_wal_io_timing = off
 #track_functions = none			# none, pl, all
+#track_toast = off
 #stats_temp_directory = 'pg_stat_tmp'
 
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 4d992dc224..22c34b96a6 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5668,6 +5668,31 @@
   proparallel => 'r', prorettype => 'float8', proargtypes => 'oid',
   prosrc => 'pg_stat_get_function_self_time' },
 
+{ oid => '9700', descr => 'statistics: number of TOAST externalizations',
+  proname => 'pg_stat_get_toast_externalizations', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_externalizations' },
+{ oid => '9701', descr => 'statistics: number of TOAST compressions',
+  proname => 'pg_stat_get_toast_compressions', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressions' },
+  { oid => '9702', descr => 'statistics: number of successful TOAST compressions',
+  proname => 'pg_stat_get_toast_compressionsuccesses', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressionsuccesses' },
+{ oid => '9703', descr => 'statistics: total original size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_originalsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_originalsizesum' },
+{ oid => '9704', descr => 'statistics: total compressed size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_compressedsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressedsizesum' },
+{ oid => '9705', descr => 'statistics: total time spend TOASTing data',
+  proname => 'pg_stat_get_toast_total_time', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_total_time' },
+
 { oid => '3037',
   descr => 'statistics: number of scans done for table/index in current transaction',
   proname => 'pg_stat_get_xact_numscans', provolatile => 'v',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5b51b58e5a..ff26aec404 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -82,10 +82,12 @@ typedef enum StatMsgType
 	PGSTAT_MTYPE_DEADLOCK,
 	PGSTAT_MTYPE_CHECKSUMFAILURE,
 	PGSTAT_MTYPE_REPLSLOT,
+	PGSTAT_MTYPE_CONNECTION,
 	PGSTAT_MTYPE_CONNECT,
 	PGSTAT_MTYPE_DISCONNECT,
 	PGSTAT_MTYPE_SUBSCRIPTIONPURGE,
 	PGSTAT_MTYPE_SUBWORKERERROR,
+	PGSTAT_MTYPE_TOASTSTAT,
 } StatMsgType;
 
 /* ----------
@@ -733,6 +735,80 @@ typedef struct PgStat_MsgDisconnect
 	SessionEndType m_cause;
 } PgStat_MsgDisconnect;
 
+/* ----------
+ * PgStat_BackendAttrIdentifier	Identifier for a single attribute/column (OID + attr)
+ * Used as a hashable identifier for (e.g.) TOAST columns
+ * ----------
+ */
+typedef struct PgStat_BackendAttrIdentifier
+{
+	Oid			relid;
+	int			attr;
+} PgStat_BackendAttrIdentifier;
+
+/* ----------
+ * PgStat_ToastCounts	The actual per-TOAST counts kept by a backend
+ *
+ * This struct should contain only actual event counters, because we memcmp
+ * it against zeroes to detect whether there are any counts to transmit.
+ *
+ * Note that the time counters are in instr_time format here.  We convert to
+ * microseconds in PgStat_Counter format when transmitting to the collector.
+ * ----------
+ */
+typedef struct PgStat_ToastCounts
+{
+	PgStat_Counter	t_numexternalized;
+	PgStat_Counter	t_numcompressed;
+	PgStat_Counter	t_numcompressionsuccess;
+	uint64		t_size_orig;
+	uint64		t_size_compressed;
+	instr_time	t_comp_time;
+} PgStat_ToastCounts;
+
+/* ----------
+ * PgStat_BackendToastEntry	Entry in backend's per-toast-attr hash table
+ * ----------
+ */
+typedef struct PgStat_BackendToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_ToastCounts 		t_counts;
+} PgStat_BackendToastEntry;
+
+/* ----------
+ * PgStat_ToastEntry			Per-TOAST-column info in a MsgFuncstat
+ * ----------
+ */
+typedef struct PgStat_ToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_Counter 			t_numexternalized;
+	PgStat_Counter 			t_numcompressed;
+	PgStat_Counter 			t_numcompressionsuccess;
+	uint64		   		t_size_orig;
+	uint64		   		t_size_compressed;
+	PgStat_Counter			t_comp_time;	/* time in microseconds */
+} PgStat_ToastEntry;
+
+/* ----------
+ * PgStat_MsgToaststat			Sent by the backend to report function
+ *								usage statistics.
+ * ----------
+ */
+#define PGSTAT_NUM_TOASTENTRIES	\
+	((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - sizeof(int))  \
+	 / sizeof(PgStat_ToastEntry))
+
+typedef struct PgStat_MsgToaststat
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+	int			m_nentries;
+	PgStat_ToastEntry m_entry[PGSTAT_NUM_TOASTENTRIES];
+} PgStat_MsgToaststat;
+
+
 /* ----------
  * PgStat_Msg					Union over all possible messages.
  * ----------
@@ -760,6 +836,7 @@ typedef union PgStat_Msg
 	PgStat_MsgSLRU msg_slru;
 	PgStat_MsgFuncstat msg_funcstat;
 	PgStat_MsgFuncpurge msg_funcpurge;
+	PgStat_MsgToaststat msg_toaststat;
 	PgStat_MsgRecoveryConflict msg_recoveryconflict;
 	PgStat_MsgDeadlock msg_deadlock;
 	PgStat_MsgTempFile msg_tempfile;
@@ -833,6 +910,7 @@ typedef struct PgStat_StatDBEntry
 	HTAB	   *tables;
 	HTAB	   *functions;
 	HTAB	   *subworkers;
+	HTAB	   *toastactivity;
 } PgStat_StatDBEntry;
 
 
@@ -1022,6 +1100,22 @@ typedef struct PgStat_StatSubWorkerEntry
 	char		last_error_message[PGSTAT_SUBWORKERERROR_MSGLEN];
 } PgStat_StatSubWorkerEntry;
 
+/* ----------
+ * PgStat_StatToastEntry			The collector's data per TOAST attribute
+ * ----------
+ */
+typedef struct PgStat_StatToastEntry
+{
+	PgStat_BackendAttrIdentifier t_id;
+	PgStat_Counter t_numexternalized;
+	PgStat_Counter t_numcompressed;
+	PgStat_Counter t_numcompressionsuccess;
+	uint64		   t_size_orig;
+	uint64		   t_size_compressed;
+	PgStat_Counter t_comp_time;	/* time in microseconds */
+} PgStat_StatToastEntry;
+
+
 /*
  * Working state needed to accumulate per-function-call timing statistics.
  */
@@ -1045,6 +1139,7 @@ typedef struct PgStat_FunctionCallUsage
  */
 extern PGDLLIMPORT bool pgstat_track_counts;
 extern PGDLLIMPORT int pgstat_track_functions;
+extern PGDLLIMPORT bool pgstat_track_toast;
 extern char *pgstat_stat_directory;
 extern char *pgstat_stat_tmpname;
 extern char *pgstat_stat_filename;
@@ -1196,12 +1291,22 @@ extern void pgstat_count_heap_delete(Relation rel);
 extern void pgstat_count_truncate(Relation rel);
 extern void pgstat_update_heap_dead_tuples(Relation rel, int delta);
 
+extern void pgstat_count_toast_insert(Relation rel, PgStat_Counter n);
+
 struct FunctionCallInfoBaseData;
 extern void pgstat_init_function_usage(struct FunctionCallInfoBaseData *fcinfo,
 									   PgStat_FunctionCallUsage *fcu);
 extern void pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu,
 									  bool finalize);
 
+extern void
+pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							instr_time start_time);
+
 extern void AtEOXact_PgStat(bool isCommit, bool parallel);
 extern void AtEOSubXact_PgStat(bool isCommit, int nestDepth);
 
@@ -1228,9 +1333,12 @@ extern PgStat_StatTabEntry *pgstat_fetch_stat_tabentry(Oid relid);
 extern PgStat_StatFuncEntry *pgstat_fetch_stat_funcentry(Oid funcid);
 extern PgStat_StatSubWorkerEntry *pgstat_fetch_stat_subworker_entry(Oid subid,
 																	Oid subrelid);
+extern PgStat_StatToastEntry *pgstat_fetch_stat_toastentry(Oid rel_id, int attr);
+extern PgStat_ArchiverStats *pgstat_fetch_stat_archiver(void);
 extern PgStat_ArchiverStats *pgstat_fetch_stat_archiver(void);
 extern PgStat_BgWriterStats *pgstat_fetch_stat_bgwriter(void);
 extern PgStat_CheckpointerStats *pgstat_fetch_stat_checkpointer(void);
+
 extern PgStat_GlobalStats *pgstat_fetch_global(void);
 extern PgStat_WalStats *pgstat_fetch_stat_wal(void);
 extern PgStat_SLRUStats *pgstat_fetch_slru(void);
diff --git a/src/test/modules/Makefile b/src/test/modules/Makefile
index dffc79b2d9..5ccc82b4b5 100644
--- a/src/test/modules/Makefile
+++ b/src/test/modules/Makefile
@@ -27,6 +27,7 @@ SUBDIRS = \
 		  test_regex \
 		  test_rls_hooks \
 		  test_shm_mq \
+		  track_toast \
 		  unsafe_tests \
 		  worker_spi
 
diff --git a/src/test/modules/track_toast/Makefile b/src/test/modules/track_toast/Makefile
new file mode 100644
index 0000000000..26089b3deb
--- /dev/null
+++ b/src/test/modules/track_toast/Makefile
@@ -0,0 +1,18 @@
+# src/test/modules/track_toast/Makefile
+
+REGRESS = track_toast
+REGRESS_OPTS = --temp-config=$(top_srcdir)/src/test/modules/track_toast/track_toast.conf
+# Disabled because these tests require "track_toast = on",
+# which typical installcheck users do not have (e.g. buildfarm clients).
+NO_INSTALLCHECK = 1
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = src/test/modules/track_toast
+top_builddir = ../../../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
diff --git a/src/test/modules/track_toast/expected/track_toast.out b/src/test/modules/track_toast/expected/track_toast.out
new file mode 100644
index 0000000000..2887d580ab
--- /dev/null
+++ b/src/test/modules/track_toast/expected/track_toast.out
@@ -0,0 +1,55 @@
+SHOW track_toast;
+ track_toast 
+-------------
+ on
+(1 row)
+
+TABLE pg_stat_toast; -- view exists
+ schemaname | reloid | attnum | relname | attname | storagemethod | externalized | compressmethod | compressattempts | compresssuccesses | compressedsize | originalsize | total_time 
+------------+--------+--------+---------+---------+---------------+--------------+----------------+------------------+-------------------+----------------+--------------+------------
+(0 rows)
+
+CREATE TABLE toast_test (cola TEXT, colb TEXT COMPRESSION lz4, colc TEXT , cold TEXT, cole TEXT);
+ALTER TABLE toast_test ALTER colc SET STORAGE EXTERNAL;
+ALTER TABLE toast_test ALTER cold SET STORAGE MAIN;
+ALTER TABLE toast_test ALTER cole SET STORAGE PLAIN;
+INSERT INTO toast_test VALUES (repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100) );
+SELECT pg_sleep(1); -- give the stats collector some time to send the stats upstream
+ pg_sleep 
+----------
+ 
+(1 row)
+
+SELECT attname
+	,storagemethod
+	,externalized
+	,compressmethod
+	,compressattempts
+	,compresssuccesses
+	,compressedsize < originalsize AS compression_works
+	, total_time > 0 AS takes_time 
+FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY attname;
+ attname | storagemethod | externalized | compressmethod | compressattempts | compresssuccesses | compression_works | takes_time 
+---------+---------------+--------------+----------------+------------------+-------------------+-------------------+------------
+ cola    | x             |            1 |                |                1 |                 1 | t                 | t
+ colb    | x             |            1 | l              |                1 |                 1 | t                 | t
+ colc    | e             |            1 |                |                0 |                 0 | f                 | t
+ cold    | m             |            0 |                |                1 |                 1 | t                 | t
+(4 rows)
+
+SELECT storagemethod,compressmethod FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY total_time DESC;
+ storagemethod | compressmethod 
+---------------+----------------
+ e             | 
+ x             | 
+ x             | l
+ m             | 
+(4 rows)
+
+DROP TABLE toast_test;
+SELECT count(*) FROM pg_stat_toast WHERE relname = 'toast_test';
+ count 
+-------
+     0
+(1 row)
+
diff --git a/src/test/modules/track_toast/sql/track_toast.sql b/src/test/modules/track_toast/sql/track_toast.sql
new file mode 100644
index 0000000000..4c3b4b996b
--- /dev/null
+++ b/src/test/modules/track_toast/sql/track_toast.sql
@@ -0,0 +1,20 @@
+SHOW track_toast;
+TABLE pg_stat_toast; -- view exists
+CREATE TABLE toast_test (cola TEXT, colb TEXT COMPRESSION lz4, colc TEXT , cold TEXT, cole TEXT);
+ALTER TABLE toast_test ALTER colc SET STORAGE EXTERNAL;
+ALTER TABLE toast_test ALTER cold SET STORAGE MAIN;
+ALTER TABLE toast_test ALTER cole SET STORAGE PLAIN;
+INSERT INTO toast_test VALUES (repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100) );
+SELECT pg_sleep(1); -- give the stats collector some time to send the stats upstream
+SELECT attname
+	,storagemethod
+	,externalized
+	,compressmethod
+	,compressattempts
+	,compresssuccesses
+	,compressedsize < originalsize AS compression_works
+	, total_time > 0 AS takes_time 
+FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY attname;
+SELECT storagemethod,compressmethod FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY total_time DESC;
+DROP TABLE toast_test;
+SELECT count(*) FROM pg_stat_toast WHERE relname = 'toast_test';
diff --git a/src/test/modules/track_toast/track_toast.conf b/src/test/modules/track_toast/track_toast.conf
new file mode 100644
index 0000000000..191f40a762
--- /dev/null
+++ b/src/test/modules/track_toast/track_toast.conf
@@ -0,0 +1 @@
+track_toast = on
\ No newline at end of file
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index b58b062b10..2b49bebcb8 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -2147,6 +2147,23 @@ pg_stat_sys_tables| SELECT pg_stat_all_tables.relid,
     pg_stat_all_tables.autoanalyze_count
    FROM pg_stat_all_tables
   WHERE ((pg_stat_all_tables.schemaname = ANY (ARRAY['pg_catalog'::name, 'information_schema'::name])) OR (pg_stat_all_tables.schemaname ~ '^pg_toast'::text));
+pg_stat_toast| SELECT n.nspname AS schemaname,
+    a.attrelid AS reloid,
+    a.attnum,
+    c.relname,
+    a.attname,
+    a.attstorage AS storagemethod,
+    pg_stat_get_toast_externalizations(a.attrelid, (a.attnum)::integer) AS externalized,
+    a.attcompression AS compressmethod,
+    pg_stat_get_toast_compressions(a.attrelid, (a.attnum)::integer) AS compressattempts,
+    pg_stat_get_toast_compressionsuccesses(a.attrelid, (a.attnum)::integer) AS compresssuccesses,
+    pg_stat_get_toast_compressedsizesum(a.attrelid, (a.attnum)::integer) AS compressedsize,
+    pg_stat_get_toast_originalsizesum(a.attrelid, (a.attnum)::integer) AS originalsize,
+    pg_stat_get_toast_total_time(a.attrelid, (a.attnum)::integer) AS total_time
+   FROM ((pg_attribute a
+     JOIN pg_class c ON ((c.oid = a.attrelid)))
+     LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace)))
+  WHERE (pg_stat_get_toast_externalizations(a.attrelid, (a.attnum)::integer) IS NOT NULL);
 pg_stat_user_functions| SELECT p.oid AS funcid,
     n.nspname AS schemaname,
     p.proname AS funcname,
-- 
2.32.0

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index afbb6c35e3..fa40befc16 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -7668,6 +7668,32 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv;
       </listitem>
      </varlistentry>
 
+     <varlistentry id="guc-track-toast" xreflabel="track_toast">
+      <term><varname>track_toast</varname> (<type>boolean</type>)
+      <indexterm>
+       <primary><varname>track_toast</varname> configuration parameter</primary>
+      </indexterm>
+      </term>
+      <listitem>
+       <para>
+        Enables tracking of <link linkend="storage-toast">TOAST</link> activities.
+        Compressions and externalizations are tracked.
+        The default is <literal>off</literal>.
+        Only superusers can change this setting.
+       </para>
+
+       <note>
+        <para>
+        Be aware that this feature, depending on the amount of TOASTable columns in
+        your databases, may significantly increase the size of the statistics files
+        and the workload of the statistics collector. It is recommended to only
+        temporarily activate this to assess the right compression and storage method
+        for (a) column(s).
+        </para>
+       </note>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="guc-stats-temp-directory" xreflabel="stats_temp_directory">
       <term><varname>stats_temp_directory</varname> (<type>string</type>)
       <indexterm>
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 62f2a3332b..32d7818096 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -610,6 +610,17 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
       yet included in <structname>pg_stat_user_functions</structname>).</entry>
      </row>
 
+     <row>
+      <entry><structname>pg_stat_toast</structname><indexterm><primary>pg_stat_toast</primary></indexterm></entry>
+      <entry>
+       One row for each column that has ever been TOASTed (compressed and/or externalized).
+       Showing the number of externalizations, compression attempts / successes, compressed and
+       uncompressed sizes etc.
+       <link linkend="monitoring-pg-stat-toast-view">
+       <structname>pg_stat_toast</structname></link> for details.
+      </entry>
+     </row>
+
      <row>
       <entry><structname>pg_stat_slru</structname><indexterm><primary>pg_stat_slru</primary></indexterm></entry>
       <entry>One row per SLRU, showing statistics of operations. See
@@ -4969,6 +4980,158 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
 
  </sect2>
 
+ <sect2 id="monitoring-pg-stat-toast-view">
+  <title><structname>pg_stat_toast</structname></title>
+
+  <indexterm>
+   <primary>pg_stat_toast</primary>
+  </indexterm>
+
+  <para>
+   The <structname>pg_stat_toast</structname> view will contain
+   one row for each column of variable size that has been TOASTed since 
+   the last statistics reset. The <xref linkend="guc-track-toast"/> parameter
+   controls whether TOAST activities are tracked or not.
+  </para>
+
+  <table id="pg-stat-toast-view" xreflabel="pg_stat_toast">
+   <title><structname>pg_stat_toast</structname> View</title>
+   <tgroup cols="1">
+    <thead>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       Column Type
+      </para>
+      <para>
+       Description
+      </para></entry>
+     </row>
+    </thead>
+
+    <tbody>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>schemaname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the schema the relation is in
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>reloid</structfield> <type>oid</type>
+      </para>
+      <para>
+       OID of the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>attnum</structfield> <type>int</type>
+      </para>
+      <para>
+       Attribute (column) number in the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>relname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>attname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the attribute (column)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>storagemethod</structfield> <type>char</type>
+      </para>
+      <para>
+       Storage method of the attribute
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>externalized</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times this attribute was externalized (pushed to TOAST relation)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressmethod</structfield> <type>char</type>
+      </para>
+      <para>
+       Compression method of the attribute (empty means default)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressattempts</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times this attribute was compressed
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compresssuccesses</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times the compression was successful (gained a size reduction)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressedsize</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total size of all compressed datums
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>originalsize</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total size of all compressed datums before compression
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>total_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Total time spent TOASTing this attribute, in microseconds.
+      </para></entry>
+     </row>
+
+    </tbody>
+   </tgroup>
+  </table>
+
+ </sect2>
+
  <sect2 id="monitoring-pg-stat-slru-view">
   <title><structname>pg_stat_slru</structname></title>
 
diff --git a/doc/src/sgml/storage.sgml b/doc/src/sgml/storage.sgml
index 7136bbe7a3..2a47922573 100644
--- a/doc/src/sgml/storage.sgml
+++ b/doc/src/sgml/storage.sgml
@@ -517,6 +517,15 @@ pages). There was no run time difference compared to an un-<acronym>TOAST</acron
 comparison table, in which all the HTML pages were cut down to 7 kB to fit.
 </para>
 
+<para>
+When you enable <xref linkend="guc-track-toast"/>, the system view
+<link linkend="monitoring-pg-stat-toast-view"><structname>pg_stat_toast</structname>
+</link> provides details on the number and effect of compression attempts,
+number of externalizations and some more useful information that enables you
+to decide if a different storage method and/or compression method would suite a
+column better.
+</para>
+
 </sect2>
 
 <sect2 id="storage-toast-inmemory">
@@ -1068,7 +1077,8 @@ data. Empty in ordinary tables.</entry>
   <type>struct varlena</type>, which includes the total length of the stored
   value and some flag bits.  Depending on the flags, the data can be either
   inline or in a <acronym>TOAST</acronym> table;
-  it might be compressed, too (see <xref linkend="storage-toast"/>).
+  it might be compressed, too (see <xref linkend="storage-toast"/> and 
+  <xref linkend="monitoring-pg-stat-toast-view"/>).
 
  </para>
  </sect2>
diff --git a/src/backend/access/table/toast_helper.c b/src/backend/access/table/toast_helper.c
index 013236b73d..f6b06e3329 100644
--- a/src/backend/access/table/toast_helper.c
+++ b/src/backend/access/table/toast_helper.c
@@ -19,6 +19,7 @@
 #include "access/toast_helper.h"
 #include "access/toast_internals.h"
 #include "catalog/pg_type_d.h"
+#include "pgstat.h"
 
 
 /*
@@ -229,7 +230,9 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 	Datum	   *value = &ttc->ttc_values[attribute];
 	Datum		new_value;
 	ToastAttrInfo *attr = &ttc->ttc_attr[attribute];
+	instr_time	start_time;
 
+	INSTR_TIME_SET_CURRENT(start_time);
 	new_value = toast_compress_datum(*value, attr->tai_compression);
 
 	if (DatumGetPointer(new_value) != NULL)
@@ -239,6 +242,12 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 			pfree(DatumGetPointer(*value));
 		*value = new_value;
 		attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
+		pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							attr->tai_size,
+							VARSIZE(DatumGetPointer(*value)),
+							start_time);
 		attr->tai_size = VARSIZE(DatumGetPointer(*value));
 		ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
 	}
@@ -246,6 +255,12 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 	{
 		/* incompressible, ignore on subsequent compression passes */
 		attr->tai_colflags |= TOASTCOL_INCOMPRESSIBLE;
+		pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							0,
+							0,
+							start_time);
 	}
 }
 
@@ -258,6 +273,9 @@ toast_tuple_externalize(ToastTupleContext *ttc, int attribute, int options)
 	Datum	   *value = &ttc->ttc_values[attribute];
 	Datum		old_value = *value;
 	ToastAttrInfo *attr = &ttc->ttc_attr[attribute];
+	instr_time	start_time;
+
+	INSTR_TIME_SET_CURRENT(start_time);
 
 	attr->tai_colflags |= TOASTCOL_IGNORE;
 	*value = toast_save_datum(ttc->ttc_rel, old_value, attr->tai_oldexternal,
@@ -266,6 +284,12 @@ toast_tuple_externalize(ToastTupleContext *ttc, int attribute, int options)
 		pfree(DatumGetPointer(old_value));
 	attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
 	ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
+	pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							true,
+							false,
+							0,
+							0,
+							start_time);
 }
 
 /*
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 61b515cdb8..3de3025488 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -1039,6 +1039,26 @@ CREATE VIEW pg_stat_user_functions AS
     WHERE P.prolang != 12  -- fast check to eliminate built-in functions
           AND pg_stat_get_function_calls(P.oid) IS NOT NULL;
 
+
+CREATE OR REPLACE VIEW pg_stat_toast AS
+ SELECT 
+    n.nspname AS schemaname,
+    a.attrelid AS reloid,
+    a.attnum AS attnum,
+    c.relname AS relname,
+    a.attname AS attname,
+    attstorage AS storagemethod,
+    pg_stat_get_toast_externalizations(a.attrelid,a.attnum) AS externalized,
+    attcompression AS compressmethod,
+    pg_stat_get_toast_compressions(a.attrelid,a.attnum) AS compressattempts,
+    pg_stat_get_toast_compressionsuccesses(a.attrelid,a.attnum) AS compresssuccesses,
+    pg_stat_get_toast_compressedsizesum(a.attrelid,a.attnum) AS compressedsize,
+    pg_stat_get_toast_originalsizesum(a.attrelid,a.attnum) AS originalsize,
+    pg_stat_get_toast_total_time(a.attrelid,a.attnum) AS total_time
+   FROM pg_attribute a
+   JOIN pg_class c ON c.oid = a.attrelid
+   LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
+  WHERE pg_stat_get_toast_externalizations(a.attrelid,a.attnum) IS NOT NULL;
 CREATE VIEW pg_stat_xact_user_functions AS
     SELECT
             P.oid AS funcid,
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 7264d2c727..c4ce619257 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -106,6 +106,7 @@
 #define PGSTAT_DB_HASH_SIZE		16
 #define PGSTAT_TAB_HASH_SIZE	512
 #define PGSTAT_FUNCTION_HASH_SIZE	512
+#define PGSTAT_TOAST_HASH_SIZE	64
 #define PGSTAT_SUBWORKER_HASH_SIZE	32
 #define PGSTAT_REPLSLOT_HASH_SIZE	32
 
@@ -116,6 +117,7 @@
  */
 bool		pgstat_track_counts = false;
 int			pgstat_track_functions = TRACK_FUNC_OFF;
+bool		pgstat_track_toast = false;
 
 /* ----------
  * Built from GUC parameter
@@ -228,6 +230,19 @@ static HTAB *pgStatFunctions = NULL;
  */
 static bool have_function_stats = false;
 
+/*
+ * Backends store per-toast-column info that's waiting to be sent to the collector
+ * in this hash table (indexed by column's PgStat_BackendAttrIdentifier).
+ */
+static HTAB *pgStatToastActions = NULL;
+
+
+/*
+ * Indicates if backend has some toast stats that it hasn't yet
+ * sent to the collector.
+ */
+static bool have_toast_stats = false;
+
 /*
  * Tuple insertion/deletion counts for an open transaction can't be propagated
  * into PgStat_TableStatus counters until we know if it is going to commit
@@ -328,7 +343,7 @@ static PgStat_StatSubWorkerEntry *pgstat_get_subworker_entry(PgStat_StatDBEntry
 static void pgstat_write_statsfiles(bool permanent, bool allDbs);
 static void pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent);
 static HTAB *pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep);
-static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 									 HTAB *subworkerhash, bool permanent);
 static void backend_read_statsfile(void);
 
@@ -340,6 +355,7 @@ static void pgstat_reset_replslot(PgStat_StatReplSlotEntry *slotstats, Timestamp
 
 static void pgstat_send_tabstat(PgStat_MsgTabstat *tsmsg, TimestampTz now);
 static void pgstat_send_funcstats(void);
+static void pgstat_send_toaststats(void);
 static void pgstat_send_slru(void);
 static void pgstat_send_subscription_purge(PgStat_MsgSubscriptionPurge *msg);
 static HTAB *pgstat_collect_oids(Oid catalogid, AttrNumber anum_oid);
@@ -373,6 +389,7 @@ static void pgstat_recv_wal(PgStat_MsgWal *msg, int len);
 static void pgstat_recv_slru(PgStat_MsgSLRU *msg, int len);
 static void pgstat_recv_funcstat(PgStat_MsgFuncstat *msg, int len);
 static void pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len);
+static void pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len);
 static void pgstat_recv_recoveryconflict(PgStat_MsgRecoveryConflict *msg, int len);
 static void pgstat_recv_deadlock(PgStat_MsgDeadlock *msg, int len);
 static void pgstat_recv_checksum_failure(PgStat_MsgChecksumFailure *msg, int len);
@@ -891,7 +908,7 @@ pgstat_report_stat(bool disconnect)
 		pgStatXactCommit == 0 && pgStatXactRollback == 0 &&
 		pgWalUsage.wal_records == prevWalUsage.wal_records &&
 		WalStats.m_wal_write == 0 && WalStats.m_wal_sync == 0 &&
-		!have_function_stats && !disconnect)
+		!have_function_stats && !have_toast_stats && !disconnect)
 		return;
 
 	/*
@@ -983,6 +1000,9 @@ pgstat_report_stat(bool disconnect)
 	/* Now, send function statistics */
 	pgstat_send_funcstats();
 
+	/* Now, send TOAST statistics */
+	pgstat_send_toaststats();
+
 	/* Send WAL statistics */
 	pgstat_send_wal(true);
 
@@ -1116,6 +1136,64 @@ pgstat_send_funcstats(void)
 	have_function_stats = false;
 }
 
+/*
+ * Subroutine for pgstat_report_stat: populate and send a toast stat message
+ */
+static void
+pgstat_send_toaststats(void)
+{
+	/* we assume this inits to all zeroes: */
+	static const PgStat_ToastCounts all_zeroes;
+
+	PgStat_MsgToaststat msg;
+	PgStat_BackendToastEntry *entry;
+	HASH_SEQ_STATUS tstat;
+
+	if (pgStatToastActions == NULL)
+		return;
+
+	pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_TOASTSTAT);
+	msg.m_databaseid = MyDatabaseId;
+	msg.m_nentries = 0;
+
+	hash_seq_init(&tstat, pgStatToastActions);
+	while ((entry = (PgStat_BackendToastEntry *) hash_seq_search(&tstat)) != NULL)
+	{
+		PgStat_ToastEntry *m_ent;
+
+		/* Skip it if no counts accumulated since last time */
+		if (memcmp(&entry->t_counts, &all_zeroes,
+				   sizeof(PgStat_ToastCounts)) == 0)
+			continue;
+
+		/* need to convert format of time accumulators */
+		m_ent = &msg.m_entry[msg.m_nentries];
+		m_ent->attr = entry->attr;
+		m_ent->t_numexternalized = entry->t_counts.t_numexternalized;
+		m_ent->t_numcompressed = entry->t_counts.t_numcompressed;
+		m_ent->t_numcompressionsuccess = entry->t_counts.t_numcompressionsuccess;
+		m_ent->t_size_orig = entry->t_counts.t_size_orig;
+		m_ent->t_size_compressed = entry->t_counts.t_size_compressed;
+		m_ent->t_comp_time = INSTR_TIME_GET_MICROSEC(entry->t_counts.t_comp_time);
+
+		if (++msg.m_nentries >= PGSTAT_NUM_TOASTENTRIES)
+		{
+			pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+						msg.m_nentries * sizeof(PgStat_ToastEntry));
+			msg.m_nentries = 0;
+		}
+
+		/* reset the entry's counts */
+		MemSet(&entry->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	if (msg.m_nentries > 0)
+		pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+					msg.m_nentries * sizeof(PgStat_ToastEntry));
+
+	have_toast_stats = false;
+}
+
 
 /* ----------
  * pgstat_vacuum_stat() -
@@ -2151,6 +2229,75 @@ pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu, bool finalize)
 	have_function_stats = true;
 }
 
+/*
+ * Report TOAST activity
+ * Called by toast_helper functions.
+ */
+void
+pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							instr_time start_time)
+{
+	PgStat_BackendAttrIdentifier toastattr = { relid, attr };
+	PgStat_BackendToastEntry *htabent;
+	instr_time	time_spent;
+	bool		found;
+
+	if (pgStatSock == PGINVALID_SOCKET || !pgstat_track_toast)
+		return;
+
+	INSTR_TIME_SET_CURRENT(time_spent);
+	INSTR_TIME_SUBTRACT(time_spent, start_time);
+
+	if (!pgStatToastActions)
+	{
+		/* First time through - initialize toast stat table */
+		HASHCTL		hash_ctl;
+
+		hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+		hash_ctl.entrysize = sizeof(PgStat_BackendToastEntry);
+		pgStatToastActions = hash_create("TOAST stat entries",
+									  PGSTAT_TOAST_HASH_SIZE,
+									  &hash_ctl,
+									  HASH_ELEM | HASH_BLOBS);
+	}
+
+	/* Get the stats entry for this TOAST attribute, create if necessary */
+	htabent = hash_search(pgStatToastActions, &toastattr,
+						  HASH_ENTER, &found);
+	if (!found)
+	{
+		MemSet(&htabent->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	/* update counters */
+	if (externalized)
+	{
+		htabent->t_counts.t_numexternalized++;
+	}
+	if (compressed)
+	{
+		htabent->t_counts.t_numcompressed++;
+		if (new_size)
+		{
+			htabent->t_counts.t_size_orig+=old_size;
+			if (new_size)
+			{
+				htabent->t_counts.t_numcompressionsuccess++;
+				htabent->t_counts.t_size_compressed+=new_size;
+			}
+		}
+	}
+	/* record time spent */
+	INSTR_TIME_ADD(htabent->t_counts.t_comp_time, time_spent);
+
+	/* indicate that we have something to send */
+	have_toast_stats = true;
+}
+
 
 /* ----------
  * pgstat_initstats() -
@@ -3028,6 +3175,35 @@ pgstat_fetch_stat_subworker_entry(Oid subid, Oid subrelid)
 	return wentry;
 }
 
+/* ----------
+ * pgstat_fetch_stat_toastentry() -
+ *
+ *	Support function for the SQL-callable pgstat* functions. Returns
+ *	the collected statistics for one TOAST attribute or NULL.
+ * ----------
+ */
+PgStat_StatToastEntry *
+pgstat_fetch_stat_toastentry(Oid rel_id, int attr)
+{
+	PgStat_StatDBEntry *dbentry;
+	PgStat_BackendAttrIdentifier toast_id = { rel_id, attr };
+	PgStat_StatToastEntry *toastentry = NULL;
+
+	/* load the stats file if needed */
+	backend_read_statsfile();
+
+	/* Lookup our database, then find the requested TOAST activity stats.  */
+	dbentry = pgstat_fetch_stat_dbentry(MyDatabaseId);
+	if (dbentry != NULL && dbentry->toastactivity != NULL)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &toast_id,
+														 HASH_FIND, NULL);
+	}
+
+	return toastentry;
+}
+
 /*
  * ---------
  * pgstat_fetch_stat_archiver() -
@@ -3708,6 +3884,10 @@ PgstatCollectorMain(int argc, char *argv[])
 					pgstat_recv_funcpurge(&msg.msg_funcpurge, len);
 					break;
 
+				case PGSTAT_MTYPE_TOASTSTAT:
+					pgstat_recv_toaststat(&msg.msg_toaststat, len);
+					break;
+
 				case PGSTAT_MTYPE_RECOVERYCONFLICT:
 					pgstat_recv_recoveryconflict(&msg.msg_recoveryconflict,
 												 len);
@@ -3852,6 +4032,14 @@ reset_dbentry_counters(PgStat_StatDBEntry *dbentry)
 									  PGSTAT_SUBWORKER_HASH_SIZE,
 									  &hash_ctl,
 									  HASH_ELEM | HASH_BLOBS);
+
+	hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+	hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+	dbentry->toastactivity = hash_create("Per-database TOAST",
+									 PGSTAT_TOAST_HASH_SIZE,
+									 &hash_ctl,
+									 HASH_ELEM | HASH_BLOBS);
+
 }
 
 /*
@@ -4059,8 +4247,8 @@ pgstat_write_statsfiles(bool permanent, bool allDbs)
 	while ((dbentry = (PgStat_StatDBEntry *) hash_seq_search(&hstat)) != NULL)
 	{
 		/*
-		 * Write out the table, function, and subscription-worker stats for
-		 * this DB into the appropriate per-DB stat file, if required.
+		 * Write out the table, function, TOAST and subscription-worker stats for this DB into the
+		 * appropriate per-DB stat file, if required.
 		 */
 		if (allDbs || pgstat_db_requested(dbentry->databaseid))
 		{
@@ -4175,9 +4363,11 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 	HASH_SEQ_STATUS tstat;
 	HASH_SEQ_STATUS fstat;
 	HASH_SEQ_STATUS sstat;
+	HASH_SEQ_STATUS ostat;
 	PgStat_StatTabEntry *tabentry;
 	PgStat_StatFuncEntry *funcentry;
 	PgStat_StatSubWorkerEntry *subwentry;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpout;
 	int32		format_id;
 	Oid			dbid = dbentry->databaseid;
@@ -4243,6 +4433,17 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 		(void) rc;				/* we'll check for error with ferror */
 	}
 
+	/*
+	 * Walk through the database's TOAST stats table.
+	 */
+	hash_seq_init(&ostat, dbentry->toastactivity);
+	while ((toastentry = (PgStat_StatToastEntry *) hash_seq_search(&ostat)) != NULL)
+	{
+		fputc('O', fpout);
+		rc = fwrite(toastentry, sizeof(PgStat_StatToastEntry), 1, fpout);
+		(void) rc;				/* we'll check for error with ferror */
+	}
+
 	/*
 	 * No more output to be done. Close the temp file and replace the old
 	 * pgstat.stat with it.  The ferror() check replaces testing for error
@@ -4483,6 +4684,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 				dbentry->tables = NULL;
 				dbentry->functions = NULL;
 				dbentry->subworkers = NULL;
+				dbentry->toastactivity = NULL;
 
 				/*
 				 * In the collector, disregard the timestamp we read from the
@@ -4528,6 +4730,14 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 												  &hash_ctl,
 												  HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
 
+				hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+				hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+				hash_ctl.hcxt = pgStatLocalContext;
+				dbentry->toastactivity = hash_create("Per-database toast information",
+												 PGSTAT_TOAST_HASH_SIZE,
+												 &hash_ctl,
+												 HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
+
 				/*
 				 * If requested, read the data from the database-specific
 				 * file.  Otherwise we just leave the hashtables empty.
@@ -4536,6 +4746,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 					pgstat_read_db_statsfile(dbentry->databaseid,
 											 dbentry->tables,
 											 dbentry->functions,
+											 dbentry->toastactivity,
 											 dbentry->subworkers,
 											 permanent);
 
@@ -4620,7 +4831,7 @@ done:
  * ----------
  */
 static void
-pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 						 HTAB *subworkerhash, bool permanent)
 {
 	PgStat_StatTabEntry *tabentry;
@@ -4629,6 +4840,8 @@ pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
 	PgStat_StatFuncEntry *funcentry;
 	PgStat_StatSubWorkerEntry subwbuf;
 	PgStat_StatSubWorkerEntry *subwentry;
+	PgStat_StatToastEntry toastbuf;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpin;
 	int32		format_id;
 	bool		found;
@@ -4777,6 +4990,32 @@ pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
 				memcpy(subwentry, &subwbuf, sizeof(subwbuf));
 				break;
 
+
+				/*
+				 * 'O'	A PgStat_StatToastEntry follows (tOast)
+				 */
+			case 'O':
+				if (fread(&toastbuf, 1, sizeof(PgStat_StatToastEntry),
+						  fpin) != sizeof(PgStat_StatToastEntry))
+				{
+					ereport(pgStatRunningInCollector ? LOG : WARNING,
+							(errmsg("corrupted statistics file \"%s\"",
+									statfile)));
+					goto done;
+				}
+
+				/*
+				 * Skip if TOAST data not wanted.
+				 */
+				if (toasthash == NULL)
+					break;
+
+				toastentry = (PgStat_StatToastEntry *) hash_search(toasthash,
+																 (void *) &toastbuf.t_id,
+																 HASH_ENTER, &found);
+				memcpy(toastentry, &toastbuf, sizeof(toastbuf));
+				break;
+
 				/*
 				 * 'E'	The EOF marker of a complete stats file.
 				 */
@@ -5452,6 +5691,8 @@ pgstat_recv_dropdb(PgStat_MsgDropdb *msg, int len)
 			hash_destroy(dbentry->functions);
 		if (dbentry->subworkers != NULL)
 			hash_destroy(dbentry->subworkers);
+		if (dbentry->toastactivity != NULL)
+			hash_destroy(dbentry->toastactivity);
 
 		if (hash_search(pgStatDBHash,
 						(void *) &dbid,
@@ -5491,10 +5732,12 @@ pgstat_recv_resetcounter(PgStat_MsgResetcounter *msg, int len)
 		hash_destroy(dbentry->functions);
 	if (dbentry->subworkers != NULL)
 		hash_destroy(dbentry->subworkers);
-
+	if (dbentry->toastactivity != NULL)
+		hash_destroy(dbentry->toastactivity);
 	dbentry->tables = NULL;
 	dbentry->functions = NULL;
 	dbentry->subworkers = NULL;
+	dbentry->toastactivity = NULL;
 
 	/*
 	 * Reset database-level stats, too.  This creates empty hash tables for
@@ -6152,6 +6395,60 @@ pgstat_recv_subscription_purge(PgStat_MsgSubscriptionPurge *msg, int len)
 	}
 }
 
+/* ----------
+ * pgstat_recv_toaststat() -
+ *
+ *	Count what the backend has done.
+ * ----------
+ */
+static void
+pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len)
+{
+	PgStat_ToastEntry *toastmsg = &(msg->m_entry[0]);
+	PgStat_StatDBEntry *dbentry;
+	PgStat_StatToastEntry *toastentry;
+	int			i;
+	bool		found;
+
+	dbentry = pgstat_get_db_entry(msg->m_databaseid, true);
+
+	/*
+	 * Process all TOAST entries in the message.
+	 */
+	for (i = 0; i < msg->m_nentries; i++, toastmsg++)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &(toastmsg->attr),
+														 HASH_ENTER, &found);
+
+		if (!found)
+		{
+			/*
+			 * If it's a new entry, initialize counters to the values
+			 * we just got.
+			 */
+			toastentry->t_numexternalized = toastmsg->t_numexternalized;
+			toastentry->t_numcompressed = toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess = toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_orig = toastmsg->t_size_orig;
+			toastentry->t_size_compressed = toastmsg->t_size_compressed;
+			toastentry->t_comp_time = toastmsg->t_comp_time;
+		}
+		else
+		{
+			/*
+			 * Otherwise add the values to the existing entry.
+			 */
+			toastentry->t_numexternalized += toastmsg->t_numexternalized;
+			toastentry->t_numcompressed += toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess += toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_orig += toastmsg->t_size_orig;
+			toastentry->t_size_compressed += toastmsg->t_size_compressed;
+			toastentry->t_comp_time += toastmsg->t_comp_time;
+		}
+	}
+}
+
 /* ----------
  * pgstat_recv_subworker_error() -
  *
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index f529c1561a..8b40c43626 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -410,6 +410,78 @@ pg_stat_get_function_self_time(PG_FUNCTION_ARGS)
 	PG_RETURN_FLOAT8(((double) funcentry->f_self_time) / 1000.0);
 }
 
+Datum
+pg_stat_get_toast_externalizations(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numexternalized);
+}
+
+Datum
+pg_stat_get_toast_compressions(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressed);
+}
+
+Datum
+pg_stat_get_toast_compressionsuccesses(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressionsuccess);
+}
+
+Datum
+pg_stat_get_toast_originalsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_orig);
+}
+
+Datum
+pg_stat_get_toast_compressedsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_compressed);
+}
+
+Datum
+pg_stat_get_toast_total_time(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_comp_time);
+}
+
 Datum
 pg_stat_get_backend_idset(PG_FUNCTION_ARGS)
 {
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index f9504d3aec..f7ff934d4e 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -1538,6 +1538,15 @@ static struct config_bool ConfigureNamesBool[] =
 		true,
 		NULL, NULL, NULL
 	},
+	{
+		{"track_toast", PGC_SUSET, STATS_COLLECTOR,
+			gettext_noop("Collects statistics on TOAST activity."),
+			NULL
+		},
+		&pgstat_track_toast,
+		false,
+		NULL, NULL, NULL
+	},
 	{
 		{"track_io_timing", PGC_SUSET, STATS_COLLECTOR,
 			gettext_noop("Collects timing statistics for database I/O activity."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index a1acd46b61..12f4bb1a38 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -607,6 +607,7 @@
 #track_io_timing = off
 #track_wal_io_timing = off
 #track_functions = none			# none, pl, all
+#track_toast = off
 #stats_temp_directory = 'pg_stat_tmp'
 
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 4d992dc224..22c34b96a6 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5668,6 +5668,31 @@
   proparallel => 'r', prorettype => 'float8', proargtypes => 'oid',
   prosrc => 'pg_stat_get_function_self_time' },
 
+{ oid => '9700', descr => 'statistics: number of TOAST externalizations',
+  proname => 'pg_stat_get_toast_externalizations', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_externalizations' },
+{ oid => '9701', descr => 'statistics: number of TOAST compressions',
+  proname => 'pg_stat_get_toast_compressions', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressions' },
+  { oid => '9702', descr => 'statistics: number of successful TOAST compressions',
+  proname => 'pg_stat_get_toast_compressionsuccesses', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressionsuccesses' },
+{ oid => '9703', descr => 'statistics: total original size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_originalsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_originalsizesum' },
+{ oid => '9704', descr => 'statistics: total compressed size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_compressedsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressedsizesum' },
+{ oid => '9705', descr => 'statistics: total time spend TOASTing data',
+  proname => 'pg_stat_get_toast_total_time', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_total_time' },
+
 { oid => '3037',
   descr => 'statistics: number of scans done for table/index in current transaction',
   proname => 'pg_stat_get_xact_numscans', provolatile => 'v',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5b51b58e5a..ff26aec404 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -82,10 +82,12 @@ typedef enum StatMsgType
 	PGSTAT_MTYPE_DEADLOCK,
 	PGSTAT_MTYPE_CHECKSUMFAILURE,
 	PGSTAT_MTYPE_REPLSLOT,
+	PGSTAT_MTYPE_CONNECTION,
 	PGSTAT_MTYPE_CONNECT,
 	PGSTAT_MTYPE_DISCONNECT,
 	PGSTAT_MTYPE_SUBSCRIPTIONPURGE,
 	PGSTAT_MTYPE_SUBWORKERERROR,
+	PGSTAT_MTYPE_TOASTSTAT,
 } StatMsgType;
 
 /* ----------
@@ -733,6 +735,80 @@ typedef struct PgStat_MsgDisconnect
 	SessionEndType m_cause;
 } PgStat_MsgDisconnect;
 
+/* ----------
+ * PgStat_BackendAttrIdentifier	Identifier for a single attribute/column (OID + attr)
+ * Used as a hashable identifier for (e.g.) TOAST columns
+ * ----------
+ */
+typedef struct PgStat_BackendAttrIdentifier
+{
+	Oid			relid;
+	int			attr;
+} PgStat_BackendAttrIdentifier;
+
+/* ----------
+ * PgStat_ToastCounts	The actual per-TOAST counts kept by a backend
+ *
+ * This struct should contain only actual event counters, because we memcmp
+ * it against zeroes to detect whether there are any counts to transmit.
+ *
+ * Note that the time counters are in instr_time format here.  We convert to
+ * microseconds in PgStat_Counter format when transmitting to the collector.
+ * ----------
+ */
+typedef struct PgStat_ToastCounts
+{
+	PgStat_Counter	t_numexternalized;
+	PgStat_Counter	t_numcompressed;
+	PgStat_Counter	t_numcompressionsuccess;
+	uint64		t_size_orig;
+	uint64		t_size_compressed;
+	instr_time	t_comp_time;
+} PgStat_ToastCounts;
+
+/* ----------
+ * PgStat_BackendToastEntry	Entry in backend's per-toast-attr hash table
+ * ----------
+ */
+typedef struct PgStat_BackendToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_ToastCounts 		t_counts;
+} PgStat_BackendToastEntry;
+
+/* ----------
+ * PgStat_ToastEntry			Per-TOAST-column info in a MsgFuncstat
+ * ----------
+ */
+typedef struct PgStat_ToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_Counter 			t_numexternalized;
+	PgStat_Counter 			t_numcompressed;
+	PgStat_Counter 			t_numcompressionsuccess;
+	uint64		   		t_size_orig;
+	uint64		   		t_size_compressed;
+	PgStat_Counter			t_comp_time;	/* time in microseconds */
+} PgStat_ToastEntry;
+
+/* ----------
+ * PgStat_MsgToaststat			Sent by the backend to report function
+ *								usage statistics.
+ * ----------
+ */
+#define PGSTAT_NUM_TOASTENTRIES	\
+	((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - sizeof(int))  \
+	 / sizeof(PgStat_ToastEntry))
+
+typedef struct PgStat_MsgToaststat
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+	int			m_nentries;
+	PgStat_ToastEntry m_entry[PGSTAT_NUM_TOASTENTRIES];
+} PgStat_MsgToaststat;
+
+
 /* ----------
  * PgStat_Msg					Union over all possible messages.
  * ----------
@@ -760,6 +836,7 @@ typedef union PgStat_Msg
 	PgStat_MsgSLRU msg_slru;
 	PgStat_MsgFuncstat msg_funcstat;
 	PgStat_MsgFuncpurge msg_funcpurge;
+	PgStat_MsgToaststat msg_toaststat;
 	PgStat_MsgRecoveryConflict msg_recoveryconflict;
 	PgStat_MsgDeadlock msg_deadlock;
 	PgStat_MsgTempFile msg_tempfile;
@@ -833,6 +910,7 @@ typedef struct PgStat_StatDBEntry
 	HTAB	   *tables;
 	HTAB	   *functions;
 	HTAB	   *subworkers;
+	HTAB	   *toastactivity;
 } PgStat_StatDBEntry;
 
 
@@ -1022,6 +1100,22 @@ typedef struct PgStat_StatSubWorkerEntry
 	char		last_error_message[PGSTAT_SUBWORKERERROR_MSGLEN];
 } PgStat_StatSubWorkerEntry;
 
+/* ----------
+ * PgStat_StatToastEntry			The collector's data per TOAST attribute
+ * ----------
+ */
+typedef struct PgStat_StatToastEntry
+{
+	PgStat_BackendAttrIdentifier t_id;
+	PgStat_Counter t_numexternalized;
+	PgStat_Counter t_numcompressed;
+	PgStat_Counter t_numcompressionsuccess;
+	uint64		   t_size_orig;
+	uint64		   t_size_compressed;
+	PgStat_Counter t_comp_time;	/* time in microseconds */
+} PgStat_StatToastEntry;
+
+
 /*
  * Working state needed to accumulate per-function-call timing statistics.
  */
@@ -1045,6 +1139,7 @@ typedef struct PgStat_FunctionCallUsage
  */
 extern PGDLLIMPORT bool pgstat_track_counts;
 extern PGDLLIMPORT int pgstat_track_functions;
+extern PGDLLIMPORT bool pgstat_track_toast;
 extern char *pgstat_stat_directory;
 extern char *pgstat_stat_tmpname;
 extern char *pgstat_stat_filename;
@@ -1196,12 +1291,22 @@ extern void pgstat_count_heap_delete(Relation rel);
 extern void pgstat_count_truncate(Relation rel);
 extern void pgstat_update_heap_dead_tuples(Relation rel, int delta);
 
+extern void pgstat_count_toast_insert(Relation rel, PgStat_Counter n);
+
 struct FunctionCallInfoBaseData;
 extern void pgstat_init_function_usage(struct FunctionCallInfoBaseData *fcinfo,
 									   PgStat_FunctionCallUsage *fcu);
 extern void pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu,
 									  bool finalize);
 
+extern void
+pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							instr_time start_time);
+
 extern void AtEOXact_PgStat(bool isCommit, bool parallel);
 extern void AtEOSubXact_PgStat(bool isCommit, int nestDepth);
 
@@ -1228,9 +1333,12 @@ extern PgStat_StatTabEntry *pgstat_fetch_stat_tabentry(Oid relid);
 extern PgStat_StatFuncEntry *pgstat_fetch_stat_funcentry(Oid funcid);
 extern PgStat_StatSubWorkerEntry *pgstat_fetch_stat_subworker_entry(Oid subid,
 																	Oid subrelid);
+extern PgStat_StatToastEntry *pgstat_fetch_stat_toastentry(Oid rel_id, int attr);
+extern PgStat_ArchiverStats *pgstat_fetch_stat_archiver(void);
 extern PgStat_ArchiverStats *pgstat_fetch_stat_archiver(void);
 extern PgStat_BgWriterStats *pgstat_fetch_stat_bgwriter(void);
 extern PgStat_CheckpointerStats *pgstat_fetch_stat_checkpointer(void);
+
 extern PgStat_GlobalStats *pgstat_fetch_global(void);
 extern PgStat_WalStats *pgstat_fetch_stat_wal(void);
 extern PgStat_SLRUStats *pgstat_fetch_slru(void);
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index b58b062b10..2b49bebcb8 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -2147,6 +2147,23 @@ pg_stat_sys_tables| SELECT pg_stat_all_tables.relid,
     pg_stat_all_tables.autoanalyze_count
    FROM pg_stat_all_tables
   WHERE ((pg_stat_all_tables.schemaname = ANY (ARRAY['pg_catalog'::name, 'information_schema'::name])) OR (pg_stat_all_tables.schemaname ~ '^pg_toast'::text));
+pg_stat_toast| SELECT n.nspname AS schemaname,
+    a.attrelid AS reloid,
+    a.attnum,
+    c.relname,
+    a.attname,
+    a.attstorage AS storagemethod,
+    pg_stat_get_toast_externalizations(a.attrelid, (a.attnum)::integer) AS externalized,
+    a.attcompression AS compressmethod,
+    pg_stat_get_toast_compressions(a.attrelid, (a.attnum)::integer) AS compressattempts,
+    pg_stat_get_toast_compressionsuccesses(a.attrelid, (a.attnum)::integer) AS compresssuccesses,
+    pg_stat_get_toast_compressedsizesum(a.attrelid, (a.attnum)::integer) AS compressedsize,
+    pg_stat_get_toast_originalsizesum(a.attrelid, (a.attnum)::integer) AS originalsize,
+    pg_stat_get_toast_total_time(a.attrelid, (a.attnum)::integer) AS total_time
+   FROM ((pg_attribute a
+     JOIN pg_class c ON ((c.oid = a.attrelid)))
+     LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace)))
+  WHERE (pg_stat_get_toast_externalizations(a.attrelid, (a.attnum)::integer) IS NOT NULL);
 pg_stat_user_functions| SELECT p.oid AS funcid,
     n.nspname AS schemaname,
     p.proname AS funcname,
diff --git a/src/test/regress/expected/track_toast.out b/src/test/regress/expected/track_toast.out
new file mode 100644
index 0000000000..1fb4a59935
--- /dev/null
+++ b/src/test/regress/expected/track_toast.out
@@ -0,0 +1,65 @@
+SHOW track_toast;
+ track_toast 
+-------------
+ off
+(1 row)
+
+SET track_toast TO on;
+SHOW track_toast;
+ track_toast 
+-------------
+ on
+(1 row)
+
+TABLE pg_stat_toast; -- view exists
+ schemaname | reloid | attnum | relname | attname | storagemethod | externalized | compressmethod | compressattempts | compresssuccesses | compressedsize | originalsize | total_time 
+------------+--------+--------+---------+---------+---------------+--------------+----------------+------------------+-------------------+----------------+--------------+------------
+(0 rows)
+
+CREATE TABLE toast_test (cola TEXT, colb TEXT COMPRESSION lz4, colc TEXT , cold TEXT, cole TEXT);
+ALTER TABLE toast_test ALTER colc SET STORAGE EXTERNAL;
+ALTER TABLE toast_test ALTER cold SET STORAGE MAIN;
+ALTER TABLE toast_test ALTER cole SET STORAGE PLAIN;
+INSERT INTO toast_test VALUES (repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100) );
+SELECT pg_sleep(1); -- give the stats collector some time to send the stats upstream
+ pg_sleep 
+----------
+ 
+(1 row)
+
+SELECT attname
+	,storagemethod
+	,externalized
+	,compressmethod
+	,compressattempts
+	,compresssuccesses
+	,compressedsize < originalsize AS compression_works
+	, total_time > 0 AS takes_time 
+FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY attname;
+ attname | storagemethod | externalized | compressmethod | compressattempts | compresssuccesses | compression_works | takes_time 
+---------+---------------+--------------+----------------+------------------+-------------------+-------------------+------------
+ cola    | x             |            1 |                |                1 |                 1 | t                 | t
+ colb    | x             |            1 | l              |                1 |                 1 | t                 | t
+ colc    | e             |            1 |                |                0 |                 0 | f                 | t
+ cold    | m             |            0 |                |                1 |                 1 | t                 | t
+(4 rows)
+
+SELECT compressattempts=0 AS external_doesnt_compress FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'e';
+ external_doesnt_compress 
+--------------------------
+ t
+(1 row)
+
+SELECT externalized=0 AS main_doesnt_externalize FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'm';
+ main_doesnt_externalize 
+-------------------------
+ t
+(1 row)
+
+DROP TABLE toast_test;
+SELECT count(*) FROM pg_stat_toast WHERE relname = 'toast_test';
+ count 
+-------
+     0
+(1 row)
+
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index 5b0c73d7e3..fc89dae4b5 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -107,7 +107,7 @@ test: publication subscription
 # ----------
 # Another group of parallel tests
 # ----------
-test: select_views portals_p2 foreign_key cluster dependency guc bitmapops combocid tsearch tsdicts foreign_data window xmlmap functional_deps advisory_lock indirect_toast equivclass
+test: select_views portals_p2 foreign_key cluster dependency guc bitmapops combocid tsearch tsdicts foreign_data window xmlmap functional_deps advisory_lock indirect_toast equivclass track_toast
 
 # ----------
 # Another group of parallel tests (JSON related)
diff --git a/src/test/regress/sql/track_toast.sql b/src/test/regress/sql/track_toast.sql
new file mode 100644
index 0000000000..5cd78af882
--- /dev/null
+++ b/src/test/regress/sql/track_toast.sql
@@ -0,0 +1,23 @@
+SHOW track_toast;
+SET track_toast TO on;
+SHOW track_toast;
+TABLE pg_stat_toast; -- view exists
+CREATE TABLE toast_test (cola TEXT, colb TEXT COMPRESSION lz4, colc TEXT , cold TEXT, cole TEXT);
+ALTER TABLE toast_test ALTER colc SET STORAGE EXTERNAL;
+ALTER TABLE toast_test ALTER cold SET STORAGE MAIN;
+ALTER TABLE toast_test ALTER cole SET STORAGE PLAIN;
+INSERT INTO toast_test VALUES (repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100) );
+SELECT pg_sleep(1); -- give the stats collector some time to send the stats upstream
+SELECT attname
+	,storagemethod
+	,externalized
+	,compressmethod
+	,compressattempts
+	,compresssuccesses
+	,compressedsize < originalsize AS compression_works
+	, total_time > 0 AS takes_time 
+FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY attname;
+SELECT compressattempts=0 AS external_doesnt_compress FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'e';
+SELECT externalized=0 AS main_doesnt_externalize FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'm';
+DROP TABLE toast_test;
+SELECT count(*) FROM pg_stat_toast WHERE relname = 'toast_test';

From e743587fbd8f6592bbfa15f53733f79c405000e2 Mon Sep 17 00:00:00 2001
From: "Gunnar \"Nick\" Bluth" <gunnar.bluth@pro-open.de>
Date: Mon, 3 Jan 2022 20:35:05 +0100
Subject: [PATCH v6] pg_stat_toast v6

---
 doc/src/sgml/config.sgml                      |  26 ++
 doc/src/sgml/monitoring.sgml                  | 163 +++++++++
 doc/src/sgml/storage.sgml                     |  12 +-
 src/backend/access/table/toast_helper.c       |  24 ++
 src/backend/catalog/system_views.sql          |  20 ++
 src/backend/postmaster/pgstat.c               | 309 +++++++++++++++++-
 src/backend/utils/adt/pgstatfuncs.c           |  72 ++++
 src/backend/utils/misc/guc.c                  |   9 +
 src/backend/utils/misc/postgresql.conf.sample |   1 +
 src/include/catalog/pg_proc.dat               |  25 ++
 src/include/pgstat.h                          | 108 ++++++
 src/test/regress/expected/rules.out           |  17 +
 src/test/regress/expected/track_toast.out     | 102 ++++++
 src/test/regress/parallel_schedule            |   2 +-
 src/test/regress/sql/track_toast.sql          |  64 ++++
 15 files changed, 946 insertions(+), 8 deletions(-)
 create mode 100644 src/test/regress/expected/track_toast.out
 create mode 100644 src/test/regress/sql/track_toast.sql

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index afbb6c35e3..fa40befc16 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -7668,6 +7668,32 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv;
       </listitem>
      </varlistentry>
 
+     <varlistentry id="guc-track-toast" xreflabel="track_toast">
+      <term><varname>track_toast</varname> (<type>boolean</type>)
+      <indexterm>
+       <primary><varname>track_toast</varname> configuration parameter</primary>
+      </indexterm>
+      </term>
+      <listitem>
+       <para>
+        Enables tracking of <link linkend="storage-toast">TOAST</link> activities.
+        Compressions and externalizations are tracked.
+        The default is <literal>off</literal>.
+        Only superusers can change this setting.
+       </para>
+
+       <note>
+        <para>
+        Be aware that this feature, depending on the amount of TOASTable columns in
+        your databases, may significantly increase the size of the statistics files
+        and the workload of the statistics collector. It is recommended to only
+        temporarily activate this to assess the right compression and storage method
+        for (a) column(s).
+        </para>
+       </note>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="guc-stats-temp-directory" xreflabel="stats_temp_directory">
       <term><varname>stats_temp_directory</varname> (<type>string</type>)
       <indexterm>
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 62f2a3332b..32d7818096 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -610,6 +610,17 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
       yet included in <structname>pg_stat_user_functions</structname>).</entry>
      </row>
 
+     <row>
+      <entry><structname>pg_stat_toast</structname><indexterm><primary>pg_stat_toast</primary></indexterm></entry>
+      <entry>
+       One row for each column that has ever been TOASTed (compressed and/or externalized).
+       Showing the number of externalizations, compression attempts / successes, compressed and
+       uncompressed sizes etc.
+       <link linkend="monitoring-pg-stat-toast-view">
+       <structname>pg_stat_toast</structname></link> for details.
+      </entry>
+     </row>
+
      <row>
       <entry><structname>pg_stat_slru</structname><indexterm><primary>pg_stat_slru</primary></indexterm></entry>
       <entry>One row per SLRU, showing statistics of operations. See
@@ -4969,6 +4980,158 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
 
  </sect2>
 
+ <sect2 id="monitoring-pg-stat-toast-view">
+  <title><structname>pg_stat_toast</structname></title>
+
+  <indexterm>
+   <primary>pg_stat_toast</primary>
+  </indexterm>
+
+  <para>
+   The <structname>pg_stat_toast</structname> view will contain
+   one row for each column of variable size that has been TOASTed since 
+   the last statistics reset. The <xref linkend="guc-track-toast"/> parameter
+   controls whether TOAST activities are tracked or not.
+  </para>
+
+  <table id="pg-stat-toast-view" xreflabel="pg_stat_toast">
+   <title><structname>pg_stat_toast</structname> View</title>
+   <tgroup cols="1">
+    <thead>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       Column Type
+      </para>
+      <para>
+       Description
+      </para></entry>
+     </row>
+    </thead>
+
+    <tbody>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>schemaname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the schema the relation is in
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>reloid</structfield> <type>oid</type>
+      </para>
+      <para>
+       OID of the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>attnum</structfield> <type>int</type>
+      </para>
+      <para>
+       Attribute (column) number in the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>relname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>attname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the attribute (column)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>storagemethod</structfield> <type>char</type>
+      </para>
+      <para>
+       Storage method of the attribute
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>externalized</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times this attribute was externalized (pushed to TOAST relation)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressmethod</structfield> <type>char</type>
+      </para>
+      <para>
+       Compression method of the attribute (empty means default)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressattempts</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times this attribute was compressed
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compresssuccesses</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times the compression was successful (gained a size reduction)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressedsize</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total size of all compressed datums
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>originalsize</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total size of all compressed datums before compression
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>total_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Total time spent TOASTing this attribute, in microseconds.
+      </para></entry>
+     </row>
+
+    </tbody>
+   </tgroup>
+  </table>
+
+ </sect2>
+
  <sect2 id="monitoring-pg-stat-slru-view">
   <title><structname>pg_stat_slru</structname></title>
 
diff --git a/doc/src/sgml/storage.sgml b/doc/src/sgml/storage.sgml
index 7136bbe7a3..2a47922573 100644
--- a/doc/src/sgml/storage.sgml
+++ b/doc/src/sgml/storage.sgml
@@ -517,6 +517,15 @@ pages). There was no run time difference compared to an un-<acronym>TOAST</acron
 comparison table, in which all the HTML pages were cut down to 7 kB to fit.
 </para>
 
+<para>
+When you enable <xref linkend="guc-track-toast"/>, the system view
+<link linkend="monitoring-pg-stat-toast-view"><structname>pg_stat_toast</structname>
+</link> provides details on the number and effect of compression attempts,
+number of externalizations and some more useful information that enables you
+to decide if a different storage method and/or compression method would suite a
+column better.
+</para>
+
 </sect2>
 
 <sect2 id="storage-toast-inmemory">
@@ -1068,7 +1077,8 @@ data. Empty in ordinary tables.</entry>
   <type>struct varlena</type>, which includes the total length of the stored
   value and some flag bits.  Depending on the flags, the data can be either
   inline or in a <acronym>TOAST</acronym> table;
-  it might be compressed, too (see <xref linkend="storage-toast"/>).
+  it might be compressed, too (see <xref linkend="storage-toast"/> and 
+  <xref linkend="monitoring-pg-stat-toast-view"/>).
 
  </para>
  </sect2>
diff --git a/src/backend/access/table/toast_helper.c b/src/backend/access/table/toast_helper.c
index 013236b73d..f6b06e3329 100644
--- a/src/backend/access/table/toast_helper.c
+++ b/src/backend/access/table/toast_helper.c
@@ -19,6 +19,7 @@
 #include "access/toast_helper.h"
 #include "access/toast_internals.h"
 #include "catalog/pg_type_d.h"
+#include "pgstat.h"
 
 
 /*
@@ -229,7 +230,9 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 	Datum	   *value = &ttc->ttc_values[attribute];
 	Datum		new_value;
 	ToastAttrInfo *attr = &ttc->ttc_attr[attribute];
+	instr_time	start_time;
 
+	INSTR_TIME_SET_CURRENT(start_time);
 	new_value = toast_compress_datum(*value, attr->tai_compression);
 
 	if (DatumGetPointer(new_value) != NULL)
@@ -239,6 +242,12 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 			pfree(DatumGetPointer(*value));
 		*value = new_value;
 		attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
+		pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							attr->tai_size,
+							VARSIZE(DatumGetPointer(*value)),
+							start_time);
 		attr->tai_size = VARSIZE(DatumGetPointer(*value));
 		ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
 	}
@@ -246,6 +255,12 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 	{
 		/* incompressible, ignore on subsequent compression passes */
 		attr->tai_colflags |= TOASTCOL_INCOMPRESSIBLE;
+		pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							0,
+							0,
+							start_time);
 	}
 }
 
@@ -258,6 +273,9 @@ toast_tuple_externalize(ToastTupleContext *ttc, int attribute, int options)
 	Datum	   *value = &ttc->ttc_values[attribute];
 	Datum		old_value = *value;
 	ToastAttrInfo *attr = &ttc->ttc_attr[attribute];
+	instr_time	start_time;
+
+	INSTR_TIME_SET_CURRENT(start_time);
 
 	attr->tai_colflags |= TOASTCOL_IGNORE;
 	*value = toast_save_datum(ttc->ttc_rel, old_value, attr->tai_oldexternal,
@@ -266,6 +284,12 @@ toast_tuple_externalize(ToastTupleContext *ttc, int attribute, int options)
 		pfree(DatumGetPointer(old_value));
 	attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
 	ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
+	pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							true,
+							false,
+							0,
+							0,
+							start_time);
 }
 
 /*
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 61b515cdb8..3de3025488 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -1039,6 +1039,26 @@ CREATE VIEW pg_stat_user_functions AS
     WHERE P.prolang != 12  -- fast check to eliminate built-in functions
           AND pg_stat_get_function_calls(P.oid) IS NOT NULL;
 
+
+CREATE OR REPLACE VIEW pg_stat_toast AS
+ SELECT 
+    n.nspname AS schemaname,
+    a.attrelid AS reloid,
+    a.attnum AS attnum,
+    c.relname AS relname,
+    a.attname AS attname,
+    attstorage AS storagemethod,
+    pg_stat_get_toast_externalizations(a.attrelid,a.attnum) AS externalized,
+    attcompression AS compressmethod,
+    pg_stat_get_toast_compressions(a.attrelid,a.attnum) AS compressattempts,
+    pg_stat_get_toast_compressionsuccesses(a.attrelid,a.attnum) AS compresssuccesses,
+    pg_stat_get_toast_compressedsizesum(a.attrelid,a.attnum) AS compressedsize,
+    pg_stat_get_toast_originalsizesum(a.attrelid,a.attnum) AS originalsize,
+    pg_stat_get_toast_total_time(a.attrelid,a.attnum) AS total_time
+   FROM pg_attribute a
+   JOIN pg_class c ON c.oid = a.attrelid
+   LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
+  WHERE pg_stat_get_toast_externalizations(a.attrelid,a.attnum) IS NOT NULL;
 CREATE VIEW pg_stat_xact_user_functions AS
     SELECT
             P.oid AS funcid,
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 7264d2c727..c4ce619257 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -106,6 +106,7 @@
 #define PGSTAT_DB_HASH_SIZE		16
 #define PGSTAT_TAB_HASH_SIZE	512
 #define PGSTAT_FUNCTION_HASH_SIZE	512
+#define PGSTAT_TOAST_HASH_SIZE	64
 #define PGSTAT_SUBWORKER_HASH_SIZE	32
 #define PGSTAT_REPLSLOT_HASH_SIZE	32
 
@@ -116,6 +117,7 @@
  */
 bool		pgstat_track_counts = false;
 int			pgstat_track_functions = TRACK_FUNC_OFF;
+bool		pgstat_track_toast = false;
 
 /* ----------
  * Built from GUC parameter
@@ -228,6 +230,19 @@ static HTAB *pgStatFunctions = NULL;
  */
 static bool have_function_stats = false;
 
+/*
+ * Backends store per-toast-column info that's waiting to be sent to the collector
+ * in this hash table (indexed by column's PgStat_BackendAttrIdentifier).
+ */
+static HTAB *pgStatToastActions = NULL;
+
+
+/*
+ * Indicates if backend has some toast stats that it hasn't yet
+ * sent to the collector.
+ */
+static bool have_toast_stats = false;
+
 /*
  * Tuple insertion/deletion counts for an open transaction can't be propagated
  * into PgStat_TableStatus counters until we know if it is going to commit
@@ -328,7 +343,7 @@ static PgStat_StatSubWorkerEntry *pgstat_get_subworker_entry(PgStat_StatDBEntry
 static void pgstat_write_statsfiles(bool permanent, bool allDbs);
 static void pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent);
 static HTAB *pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep);
-static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 									 HTAB *subworkerhash, bool permanent);
 static void backend_read_statsfile(void);
 
@@ -340,6 +355,7 @@ static void pgstat_reset_replslot(PgStat_StatReplSlotEntry *slotstats, Timestamp
 
 static void pgstat_send_tabstat(PgStat_MsgTabstat *tsmsg, TimestampTz now);
 static void pgstat_send_funcstats(void);
+static void pgstat_send_toaststats(void);
 static void pgstat_send_slru(void);
 static void pgstat_send_subscription_purge(PgStat_MsgSubscriptionPurge *msg);
 static HTAB *pgstat_collect_oids(Oid catalogid, AttrNumber anum_oid);
@@ -373,6 +389,7 @@ static void pgstat_recv_wal(PgStat_MsgWal *msg, int len);
 static void pgstat_recv_slru(PgStat_MsgSLRU *msg, int len);
 static void pgstat_recv_funcstat(PgStat_MsgFuncstat *msg, int len);
 static void pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len);
+static void pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len);
 static void pgstat_recv_recoveryconflict(PgStat_MsgRecoveryConflict *msg, int len);
 static void pgstat_recv_deadlock(PgStat_MsgDeadlock *msg, int len);
 static void pgstat_recv_checksum_failure(PgStat_MsgChecksumFailure *msg, int len);
@@ -891,7 +908,7 @@ pgstat_report_stat(bool disconnect)
 		pgStatXactCommit == 0 && pgStatXactRollback == 0 &&
 		pgWalUsage.wal_records == prevWalUsage.wal_records &&
 		WalStats.m_wal_write == 0 && WalStats.m_wal_sync == 0 &&
-		!have_function_stats && !disconnect)
+		!have_function_stats && !have_toast_stats && !disconnect)
 		return;
 
 	/*
@@ -983,6 +1000,9 @@ pgstat_report_stat(bool disconnect)
 	/* Now, send function statistics */
 	pgstat_send_funcstats();
 
+	/* Now, send TOAST statistics */
+	pgstat_send_toaststats();
+
 	/* Send WAL statistics */
 	pgstat_send_wal(true);
 
@@ -1116,6 +1136,64 @@ pgstat_send_funcstats(void)
 	have_function_stats = false;
 }
 
+/*
+ * Subroutine for pgstat_report_stat: populate and send a toast stat message
+ */
+static void
+pgstat_send_toaststats(void)
+{
+	/* we assume this inits to all zeroes: */
+	static const PgStat_ToastCounts all_zeroes;
+
+	PgStat_MsgToaststat msg;
+	PgStat_BackendToastEntry *entry;
+	HASH_SEQ_STATUS tstat;
+
+	if (pgStatToastActions == NULL)
+		return;
+
+	pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_TOASTSTAT);
+	msg.m_databaseid = MyDatabaseId;
+	msg.m_nentries = 0;
+
+	hash_seq_init(&tstat, pgStatToastActions);
+	while ((entry = (PgStat_BackendToastEntry *) hash_seq_search(&tstat)) != NULL)
+	{
+		PgStat_ToastEntry *m_ent;
+
+		/* Skip it if no counts accumulated since last time */
+		if (memcmp(&entry->t_counts, &all_zeroes,
+				   sizeof(PgStat_ToastCounts)) == 0)
+			continue;
+
+		/* need to convert format of time accumulators */
+		m_ent = &msg.m_entry[msg.m_nentries];
+		m_ent->attr = entry->attr;
+		m_ent->t_numexternalized = entry->t_counts.t_numexternalized;
+		m_ent->t_numcompressed = entry->t_counts.t_numcompressed;
+		m_ent->t_numcompressionsuccess = entry->t_counts.t_numcompressionsuccess;
+		m_ent->t_size_orig = entry->t_counts.t_size_orig;
+		m_ent->t_size_compressed = entry->t_counts.t_size_compressed;
+		m_ent->t_comp_time = INSTR_TIME_GET_MICROSEC(entry->t_counts.t_comp_time);
+
+		if (++msg.m_nentries >= PGSTAT_NUM_TOASTENTRIES)
+		{
+			pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+						msg.m_nentries * sizeof(PgStat_ToastEntry));
+			msg.m_nentries = 0;
+		}
+
+		/* reset the entry's counts */
+		MemSet(&entry->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	if (msg.m_nentries > 0)
+		pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+					msg.m_nentries * sizeof(PgStat_ToastEntry));
+
+	have_toast_stats = false;
+}
+
 
 /* ----------
  * pgstat_vacuum_stat() -
@@ -2151,6 +2229,75 @@ pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu, bool finalize)
 	have_function_stats = true;
 }
 
+/*
+ * Report TOAST activity
+ * Called by toast_helper functions.
+ */
+void
+pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							instr_time start_time)
+{
+	PgStat_BackendAttrIdentifier toastattr = { relid, attr };
+	PgStat_BackendToastEntry *htabent;
+	instr_time	time_spent;
+	bool		found;
+
+	if (pgStatSock == PGINVALID_SOCKET || !pgstat_track_toast)
+		return;
+
+	INSTR_TIME_SET_CURRENT(time_spent);
+	INSTR_TIME_SUBTRACT(time_spent, start_time);
+
+	if (!pgStatToastActions)
+	{
+		/* First time through - initialize toast stat table */
+		HASHCTL		hash_ctl;
+
+		hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+		hash_ctl.entrysize = sizeof(PgStat_BackendToastEntry);
+		pgStatToastActions = hash_create("TOAST stat entries",
+									  PGSTAT_TOAST_HASH_SIZE,
+									  &hash_ctl,
+									  HASH_ELEM | HASH_BLOBS);
+	}
+
+	/* Get the stats entry for this TOAST attribute, create if necessary */
+	htabent = hash_search(pgStatToastActions, &toastattr,
+						  HASH_ENTER, &found);
+	if (!found)
+	{
+		MemSet(&htabent->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	/* update counters */
+	if (externalized)
+	{
+		htabent->t_counts.t_numexternalized++;
+	}
+	if (compressed)
+	{
+		htabent->t_counts.t_numcompressed++;
+		if (new_size)
+		{
+			htabent->t_counts.t_size_orig+=old_size;
+			if (new_size)
+			{
+				htabent->t_counts.t_numcompressionsuccess++;
+				htabent->t_counts.t_size_compressed+=new_size;
+			}
+		}
+	}
+	/* record time spent */
+	INSTR_TIME_ADD(htabent->t_counts.t_comp_time, time_spent);
+
+	/* indicate that we have something to send */
+	have_toast_stats = true;
+}
+
 
 /* ----------
  * pgstat_initstats() -
@@ -3028,6 +3175,35 @@ pgstat_fetch_stat_subworker_entry(Oid subid, Oid subrelid)
 	return wentry;
 }
 
+/* ----------
+ * pgstat_fetch_stat_toastentry() -
+ *
+ *	Support function for the SQL-callable pgstat* functions. Returns
+ *	the collected statistics for one TOAST attribute or NULL.
+ * ----------
+ */
+PgStat_StatToastEntry *
+pgstat_fetch_stat_toastentry(Oid rel_id, int attr)
+{
+	PgStat_StatDBEntry *dbentry;
+	PgStat_BackendAttrIdentifier toast_id = { rel_id, attr };
+	PgStat_StatToastEntry *toastentry = NULL;
+
+	/* load the stats file if needed */
+	backend_read_statsfile();
+
+	/* Lookup our database, then find the requested TOAST activity stats.  */
+	dbentry = pgstat_fetch_stat_dbentry(MyDatabaseId);
+	if (dbentry != NULL && dbentry->toastactivity != NULL)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &toast_id,
+														 HASH_FIND, NULL);
+	}
+
+	return toastentry;
+}
+
 /*
  * ---------
  * pgstat_fetch_stat_archiver() -
@@ -3708,6 +3884,10 @@ PgstatCollectorMain(int argc, char *argv[])
 					pgstat_recv_funcpurge(&msg.msg_funcpurge, len);
 					break;
 
+				case PGSTAT_MTYPE_TOASTSTAT:
+					pgstat_recv_toaststat(&msg.msg_toaststat, len);
+					break;
+
 				case PGSTAT_MTYPE_RECOVERYCONFLICT:
 					pgstat_recv_recoveryconflict(&msg.msg_recoveryconflict,
 												 len);
@@ -3852,6 +4032,14 @@ reset_dbentry_counters(PgStat_StatDBEntry *dbentry)
 									  PGSTAT_SUBWORKER_HASH_SIZE,
 									  &hash_ctl,
 									  HASH_ELEM | HASH_BLOBS);
+
+	hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+	hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+	dbentry->toastactivity = hash_create("Per-database TOAST",
+									 PGSTAT_TOAST_HASH_SIZE,
+									 &hash_ctl,
+									 HASH_ELEM | HASH_BLOBS);
+
 }
 
 /*
@@ -4059,8 +4247,8 @@ pgstat_write_statsfiles(bool permanent, bool allDbs)
 	while ((dbentry = (PgStat_StatDBEntry *) hash_seq_search(&hstat)) != NULL)
 	{
 		/*
-		 * Write out the table, function, and subscription-worker stats for
-		 * this DB into the appropriate per-DB stat file, if required.
+		 * Write out the table, function, TOAST and subscription-worker stats for this DB into the
+		 * appropriate per-DB stat file, if required.
 		 */
 		if (allDbs || pgstat_db_requested(dbentry->databaseid))
 		{
@@ -4175,9 +4363,11 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 	HASH_SEQ_STATUS tstat;
 	HASH_SEQ_STATUS fstat;
 	HASH_SEQ_STATUS sstat;
+	HASH_SEQ_STATUS ostat;
 	PgStat_StatTabEntry *tabentry;
 	PgStat_StatFuncEntry *funcentry;
 	PgStat_StatSubWorkerEntry *subwentry;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpout;
 	int32		format_id;
 	Oid			dbid = dbentry->databaseid;
@@ -4243,6 +4433,17 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 		(void) rc;				/* we'll check for error with ferror */
 	}
 
+	/*
+	 * Walk through the database's TOAST stats table.
+	 */
+	hash_seq_init(&ostat, dbentry->toastactivity);
+	while ((toastentry = (PgStat_StatToastEntry *) hash_seq_search(&ostat)) != NULL)
+	{
+		fputc('O', fpout);
+		rc = fwrite(toastentry, sizeof(PgStat_StatToastEntry), 1, fpout);
+		(void) rc;				/* we'll check for error with ferror */
+	}
+
 	/*
 	 * No more output to be done. Close the temp file and replace the old
 	 * pgstat.stat with it.  The ferror() check replaces testing for error
@@ -4483,6 +4684,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 				dbentry->tables = NULL;
 				dbentry->functions = NULL;
 				dbentry->subworkers = NULL;
+				dbentry->toastactivity = NULL;
 
 				/*
 				 * In the collector, disregard the timestamp we read from the
@@ -4528,6 +4730,14 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 												  &hash_ctl,
 												  HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
 
+				hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+				hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+				hash_ctl.hcxt = pgStatLocalContext;
+				dbentry->toastactivity = hash_create("Per-database toast information",
+												 PGSTAT_TOAST_HASH_SIZE,
+												 &hash_ctl,
+												 HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
+
 				/*
 				 * If requested, read the data from the database-specific
 				 * file.  Otherwise we just leave the hashtables empty.
@@ -4536,6 +4746,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 					pgstat_read_db_statsfile(dbentry->databaseid,
 											 dbentry->tables,
 											 dbentry->functions,
+											 dbentry->toastactivity,
 											 dbentry->subworkers,
 											 permanent);
 
@@ -4620,7 +4831,7 @@ done:
  * ----------
  */
 static void
-pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 						 HTAB *subworkerhash, bool permanent)
 {
 	PgStat_StatTabEntry *tabentry;
@@ -4629,6 +4840,8 @@ pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
 	PgStat_StatFuncEntry *funcentry;
 	PgStat_StatSubWorkerEntry subwbuf;
 	PgStat_StatSubWorkerEntry *subwentry;
+	PgStat_StatToastEntry toastbuf;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpin;
 	int32		format_id;
 	bool		found;
@@ -4777,6 +4990,32 @@ pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
 				memcpy(subwentry, &subwbuf, sizeof(subwbuf));
 				break;
 
+
+				/*
+				 * 'O'	A PgStat_StatToastEntry follows (tOast)
+				 */
+			case 'O':
+				if (fread(&toastbuf, 1, sizeof(PgStat_StatToastEntry),
+						  fpin) != sizeof(PgStat_StatToastEntry))
+				{
+					ereport(pgStatRunningInCollector ? LOG : WARNING,
+							(errmsg("corrupted statistics file \"%s\"",
+									statfile)));
+					goto done;
+				}
+
+				/*
+				 * Skip if TOAST data not wanted.
+				 */
+				if (toasthash == NULL)
+					break;
+
+				toastentry = (PgStat_StatToastEntry *) hash_search(toasthash,
+																 (void *) &toastbuf.t_id,
+																 HASH_ENTER, &found);
+				memcpy(toastentry, &toastbuf, sizeof(toastbuf));
+				break;
+
 				/*
 				 * 'E'	The EOF marker of a complete stats file.
 				 */
@@ -5452,6 +5691,8 @@ pgstat_recv_dropdb(PgStat_MsgDropdb *msg, int len)
 			hash_destroy(dbentry->functions);
 		if (dbentry->subworkers != NULL)
 			hash_destroy(dbentry->subworkers);
+		if (dbentry->toastactivity != NULL)
+			hash_destroy(dbentry->toastactivity);
 
 		if (hash_search(pgStatDBHash,
 						(void *) &dbid,
@@ -5491,10 +5732,12 @@ pgstat_recv_resetcounter(PgStat_MsgResetcounter *msg, int len)
 		hash_destroy(dbentry->functions);
 	if (dbentry->subworkers != NULL)
 		hash_destroy(dbentry->subworkers);
-
+	if (dbentry->toastactivity != NULL)
+		hash_destroy(dbentry->toastactivity);
 	dbentry->tables = NULL;
 	dbentry->functions = NULL;
 	dbentry->subworkers = NULL;
+	dbentry->toastactivity = NULL;
 
 	/*
 	 * Reset database-level stats, too.  This creates empty hash tables for
@@ -6152,6 +6395,60 @@ pgstat_recv_subscription_purge(PgStat_MsgSubscriptionPurge *msg, int len)
 	}
 }
 
+/* ----------
+ * pgstat_recv_toaststat() -
+ *
+ *	Count what the backend has done.
+ * ----------
+ */
+static void
+pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len)
+{
+	PgStat_ToastEntry *toastmsg = &(msg->m_entry[0]);
+	PgStat_StatDBEntry *dbentry;
+	PgStat_StatToastEntry *toastentry;
+	int			i;
+	bool		found;
+
+	dbentry = pgstat_get_db_entry(msg->m_databaseid, true);
+
+	/*
+	 * Process all TOAST entries in the message.
+	 */
+	for (i = 0; i < msg->m_nentries; i++, toastmsg++)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &(toastmsg->attr),
+														 HASH_ENTER, &found);
+
+		if (!found)
+		{
+			/*
+			 * If it's a new entry, initialize counters to the values
+			 * we just got.
+			 */
+			toastentry->t_numexternalized = toastmsg->t_numexternalized;
+			toastentry->t_numcompressed = toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess = toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_orig = toastmsg->t_size_orig;
+			toastentry->t_size_compressed = toastmsg->t_size_compressed;
+			toastentry->t_comp_time = toastmsg->t_comp_time;
+		}
+		else
+		{
+			/*
+			 * Otherwise add the values to the existing entry.
+			 */
+			toastentry->t_numexternalized += toastmsg->t_numexternalized;
+			toastentry->t_numcompressed += toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess += toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_orig += toastmsg->t_size_orig;
+			toastentry->t_size_compressed += toastmsg->t_size_compressed;
+			toastentry->t_comp_time += toastmsg->t_comp_time;
+		}
+	}
+}
+
 /* ----------
  * pgstat_recv_subworker_error() -
  *
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index f529c1561a..8b40c43626 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -410,6 +410,78 @@ pg_stat_get_function_self_time(PG_FUNCTION_ARGS)
 	PG_RETURN_FLOAT8(((double) funcentry->f_self_time) / 1000.0);
 }
 
+Datum
+pg_stat_get_toast_externalizations(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numexternalized);
+}
+
+Datum
+pg_stat_get_toast_compressions(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressed);
+}
+
+Datum
+pg_stat_get_toast_compressionsuccesses(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressionsuccess);
+}
+
+Datum
+pg_stat_get_toast_originalsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_orig);
+}
+
+Datum
+pg_stat_get_toast_compressedsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_compressed);
+}
+
+Datum
+pg_stat_get_toast_total_time(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_comp_time);
+}
+
 Datum
 pg_stat_get_backend_idset(PG_FUNCTION_ARGS)
 {
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index f9504d3aec..f7ff934d4e 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -1538,6 +1538,15 @@ static struct config_bool ConfigureNamesBool[] =
 		true,
 		NULL, NULL, NULL
 	},
+	{
+		{"track_toast", PGC_SUSET, STATS_COLLECTOR,
+			gettext_noop("Collects statistics on TOAST activity."),
+			NULL
+		},
+		&pgstat_track_toast,
+		false,
+		NULL, NULL, NULL
+	},
 	{
 		{"track_io_timing", PGC_SUSET, STATS_COLLECTOR,
 			gettext_noop("Collects timing statistics for database I/O activity."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index a1acd46b61..12f4bb1a38 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -607,6 +607,7 @@
 #track_io_timing = off
 #track_wal_io_timing = off
 #track_functions = none			# none, pl, all
+#track_toast = off
 #stats_temp_directory = 'pg_stat_tmp'
 
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 4d992dc224..22c34b96a6 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5668,6 +5668,31 @@
   proparallel => 'r', prorettype => 'float8', proargtypes => 'oid',
   prosrc => 'pg_stat_get_function_self_time' },
 
+{ oid => '9700', descr => 'statistics: number of TOAST externalizations',
+  proname => 'pg_stat_get_toast_externalizations', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_externalizations' },
+{ oid => '9701', descr => 'statistics: number of TOAST compressions',
+  proname => 'pg_stat_get_toast_compressions', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressions' },
+  { oid => '9702', descr => 'statistics: number of successful TOAST compressions',
+  proname => 'pg_stat_get_toast_compressionsuccesses', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressionsuccesses' },
+{ oid => '9703', descr => 'statistics: total original size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_originalsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_originalsizesum' },
+{ oid => '9704', descr => 'statistics: total compressed size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_compressedsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressedsizesum' },
+{ oid => '9705', descr => 'statistics: total time spend TOASTing data',
+  proname => 'pg_stat_get_toast_total_time', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_total_time' },
+
 { oid => '3037',
   descr => 'statistics: number of scans done for table/index in current transaction',
   proname => 'pg_stat_get_xact_numscans', provolatile => 'v',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5b51b58e5a..ff26aec404 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -82,10 +82,12 @@ typedef enum StatMsgType
 	PGSTAT_MTYPE_DEADLOCK,
 	PGSTAT_MTYPE_CHECKSUMFAILURE,
 	PGSTAT_MTYPE_REPLSLOT,
+	PGSTAT_MTYPE_CONNECTION,
 	PGSTAT_MTYPE_CONNECT,
 	PGSTAT_MTYPE_DISCONNECT,
 	PGSTAT_MTYPE_SUBSCRIPTIONPURGE,
 	PGSTAT_MTYPE_SUBWORKERERROR,
+	PGSTAT_MTYPE_TOASTSTAT,
 } StatMsgType;
 
 /* ----------
@@ -733,6 +735,80 @@ typedef struct PgStat_MsgDisconnect
 	SessionEndType m_cause;
 } PgStat_MsgDisconnect;
 
+/* ----------
+ * PgStat_BackendAttrIdentifier	Identifier for a single attribute/column (OID + attr)
+ * Used as a hashable identifier for (e.g.) TOAST columns
+ * ----------
+ */
+typedef struct PgStat_BackendAttrIdentifier
+{
+	Oid			relid;
+	int			attr;
+} PgStat_BackendAttrIdentifier;
+
+/* ----------
+ * PgStat_ToastCounts	The actual per-TOAST counts kept by a backend
+ *
+ * This struct should contain only actual event counters, because we memcmp
+ * it against zeroes to detect whether there are any counts to transmit.
+ *
+ * Note that the time counters are in instr_time format here.  We convert to
+ * microseconds in PgStat_Counter format when transmitting to the collector.
+ * ----------
+ */
+typedef struct PgStat_ToastCounts
+{
+	PgStat_Counter	t_numexternalized;
+	PgStat_Counter	t_numcompressed;
+	PgStat_Counter	t_numcompressionsuccess;
+	uint64		t_size_orig;
+	uint64		t_size_compressed;
+	instr_time	t_comp_time;
+} PgStat_ToastCounts;
+
+/* ----------
+ * PgStat_BackendToastEntry	Entry in backend's per-toast-attr hash table
+ * ----------
+ */
+typedef struct PgStat_BackendToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_ToastCounts 		t_counts;
+} PgStat_BackendToastEntry;
+
+/* ----------
+ * PgStat_ToastEntry			Per-TOAST-column info in a MsgFuncstat
+ * ----------
+ */
+typedef struct PgStat_ToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_Counter 			t_numexternalized;
+	PgStat_Counter 			t_numcompressed;
+	PgStat_Counter 			t_numcompressionsuccess;
+	uint64		   		t_size_orig;
+	uint64		   		t_size_compressed;
+	PgStat_Counter			t_comp_time;	/* time in microseconds */
+} PgStat_ToastEntry;
+
+/* ----------
+ * PgStat_MsgToaststat			Sent by the backend to report function
+ *								usage statistics.
+ * ----------
+ */
+#define PGSTAT_NUM_TOASTENTRIES	\
+	((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - sizeof(int))  \
+	 / sizeof(PgStat_ToastEntry))
+
+typedef struct PgStat_MsgToaststat
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+	int			m_nentries;
+	PgStat_ToastEntry m_entry[PGSTAT_NUM_TOASTENTRIES];
+} PgStat_MsgToaststat;
+
+
 /* ----------
  * PgStat_Msg					Union over all possible messages.
  * ----------
@@ -760,6 +836,7 @@ typedef union PgStat_Msg
 	PgStat_MsgSLRU msg_slru;
 	PgStat_MsgFuncstat msg_funcstat;
 	PgStat_MsgFuncpurge msg_funcpurge;
+	PgStat_MsgToaststat msg_toaststat;
 	PgStat_MsgRecoveryConflict msg_recoveryconflict;
 	PgStat_MsgDeadlock msg_deadlock;
 	PgStat_MsgTempFile msg_tempfile;
@@ -833,6 +910,7 @@ typedef struct PgStat_StatDBEntry
 	HTAB	   *tables;
 	HTAB	   *functions;
 	HTAB	   *subworkers;
+	HTAB	   *toastactivity;
 } PgStat_StatDBEntry;
 
 
@@ -1022,6 +1100,22 @@ typedef struct PgStat_StatSubWorkerEntry
 	char		last_error_message[PGSTAT_SUBWORKERERROR_MSGLEN];
 } PgStat_StatSubWorkerEntry;
 
+/* ----------
+ * PgStat_StatToastEntry			The collector's data per TOAST attribute
+ * ----------
+ */
+typedef struct PgStat_StatToastEntry
+{
+	PgStat_BackendAttrIdentifier t_id;
+	PgStat_Counter t_numexternalized;
+	PgStat_Counter t_numcompressed;
+	PgStat_Counter t_numcompressionsuccess;
+	uint64		   t_size_orig;
+	uint64		   t_size_compressed;
+	PgStat_Counter t_comp_time;	/* time in microseconds */
+} PgStat_StatToastEntry;
+
+
 /*
  * Working state needed to accumulate per-function-call timing statistics.
  */
@@ -1045,6 +1139,7 @@ typedef struct PgStat_FunctionCallUsage
  */
 extern PGDLLIMPORT bool pgstat_track_counts;
 extern PGDLLIMPORT int pgstat_track_functions;
+extern PGDLLIMPORT bool pgstat_track_toast;
 extern char *pgstat_stat_directory;
 extern char *pgstat_stat_tmpname;
 extern char *pgstat_stat_filename;
@@ -1196,12 +1291,22 @@ extern void pgstat_count_heap_delete(Relation rel);
 extern void pgstat_count_truncate(Relation rel);
 extern void pgstat_update_heap_dead_tuples(Relation rel, int delta);
 
+extern void pgstat_count_toast_insert(Relation rel, PgStat_Counter n);
+
 struct FunctionCallInfoBaseData;
 extern void pgstat_init_function_usage(struct FunctionCallInfoBaseData *fcinfo,
 									   PgStat_FunctionCallUsage *fcu);
 extern void pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu,
 									  bool finalize);
 
+extern void
+pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							instr_time start_time);
+
 extern void AtEOXact_PgStat(bool isCommit, bool parallel);
 extern void AtEOSubXact_PgStat(bool isCommit, int nestDepth);
 
@@ -1228,9 +1333,12 @@ extern PgStat_StatTabEntry *pgstat_fetch_stat_tabentry(Oid relid);
 extern PgStat_StatFuncEntry *pgstat_fetch_stat_funcentry(Oid funcid);
 extern PgStat_StatSubWorkerEntry *pgstat_fetch_stat_subworker_entry(Oid subid,
 																	Oid subrelid);
+extern PgStat_StatToastEntry *pgstat_fetch_stat_toastentry(Oid rel_id, int attr);
+extern PgStat_ArchiverStats *pgstat_fetch_stat_archiver(void);
 extern PgStat_ArchiverStats *pgstat_fetch_stat_archiver(void);
 extern PgStat_BgWriterStats *pgstat_fetch_stat_bgwriter(void);
 extern PgStat_CheckpointerStats *pgstat_fetch_stat_checkpointer(void);
+
 extern PgStat_GlobalStats *pgstat_fetch_global(void);
 extern PgStat_WalStats *pgstat_fetch_stat_wal(void);
 extern PgStat_SLRUStats *pgstat_fetch_slru(void);
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index b58b062b10..2b49bebcb8 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -2147,6 +2147,23 @@ pg_stat_sys_tables| SELECT pg_stat_all_tables.relid,
     pg_stat_all_tables.autoanalyze_count
    FROM pg_stat_all_tables
   WHERE ((pg_stat_all_tables.schemaname = ANY (ARRAY['pg_catalog'::name, 'information_schema'::name])) OR (pg_stat_all_tables.schemaname ~ '^pg_toast'::text));
+pg_stat_toast| SELECT n.nspname AS schemaname,
+    a.attrelid AS reloid,
+    a.attnum,
+    c.relname,
+    a.attname,
+    a.attstorage AS storagemethod,
+    pg_stat_get_toast_externalizations(a.attrelid, (a.attnum)::integer) AS externalized,
+    a.attcompression AS compressmethod,
+    pg_stat_get_toast_compressions(a.attrelid, (a.attnum)::integer) AS compressattempts,
+    pg_stat_get_toast_compressionsuccesses(a.attrelid, (a.attnum)::integer) AS compresssuccesses,
+    pg_stat_get_toast_compressedsizesum(a.attrelid, (a.attnum)::integer) AS compressedsize,
+    pg_stat_get_toast_originalsizesum(a.attrelid, (a.attnum)::integer) AS originalsize,
+    pg_stat_get_toast_total_time(a.attrelid, (a.attnum)::integer) AS total_time
+   FROM ((pg_attribute a
+     JOIN pg_class c ON ((c.oid = a.attrelid)))
+     LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace)))
+  WHERE (pg_stat_get_toast_externalizations(a.attrelid, (a.attnum)::integer) IS NOT NULL);
 pg_stat_user_functions| SELECT p.oid AS funcid,
     n.nspname AS schemaname,
     p.proname AS funcname,
diff --git a/src/test/regress/expected/track_toast.out b/src/test/regress/expected/track_toast.out
new file mode 100644
index 0000000000..8e9815fbb8
--- /dev/null
+++ b/src/test/regress/expected/track_toast.out
@@ -0,0 +1,102 @@
+SHOW track_toast;
+ track_toast 
+-------------
+ off
+(1 row)
+
+SET track_toast TO on;
+SHOW track_toast;
+ track_toast 
+-------------
+ on
+(1 row)
+
+TABLE pg_stat_toast; -- view exists
+ schemaname | reloid | attnum | relname | attname | storagemethod | externalized | compressmethod | compressattempts | compresssuccesses | compressedsize | originalsize | total_time 
+------------+--------+--------+---------+---------+---------------+--------------+----------------+------------------+-------------------+----------------+--------------+------------
+(0 rows)
+
+-- function to wait for counters to advance
+create function wait_for_stats() returns void as $$
+declare
+  start_time timestamptz := clock_timestamp();
+  updated1 bool;
+begin
+  -- we don't want to wait forever; loop will exit after 30 seconds
+  for i in 1 .. 300 loop
+
+    -- check to see if seqscan has been sensed
+    SELECT (st.n_tup_ins > 0) INTO updated1
+      FROM pg_stat_user_tables AS st
+     WHERE st.relname='toast_test';
+
+    exit when updated1;
+
+    -- wait a little
+    perform pg_sleep_for('100 milliseconds');
+
+    -- reset stats snapshot so we can test again
+    perform pg_stat_clear_snapshot();
+
+  end loop;
+
+  -- report time waited in postmaster log (where it won't change test output)
+  raise log 'wait_for_stats delayed % seconds',
+    extract(epoch from clock_timestamp() - start_time);
+end
+$$ language plpgsql;
+CREATE TABLE toast_test (cola TEXT, colb TEXT COMPRESSION lz4, colc TEXT , cold TEXT, cole TEXT);
+ALTER TABLE toast_test ALTER colc SET STORAGE EXTERNAL;
+ALTER TABLE toast_test ALTER cold SET STORAGE MAIN;
+ALTER TABLE toast_test ALTER cole SET STORAGE PLAIN;
+INSERT INTO toast_test VALUES (repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100) );
+-- We can't just call wait_for_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_stats();
+ wait_for_stats 
+----------------
+ 
+(1 row)
+
+SELECT attname
+	,storagemethod
+	,externalized
+	,compressmethod
+	,compressattempts
+	,compresssuccesses
+	,compressedsize < originalsize AS compression_works
+	, total_time > 0 AS takes_time 
+FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY attname;
+ attname | storagemethod | externalized | compressmethod | compressattempts | compresssuccesses | compression_works | takes_time 
+---------+---------------+--------------+----------------+------------------+-------------------+-------------------+------------
+ cola    | x             |            1 |                |                1 |                 1 | t                 | t
+ colb    | x             |            1 | l              |                1 |                 1 | t                 | t
+ colc    | e             |            1 |                |                0 |                 0 | f                 | t
+ cold    | m             |            0 |                |                1 |                 1 | t                 | t
+(4 rows)
+
+SELECT compressattempts=0 AS external_doesnt_compress FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'e';
+ external_doesnt_compress 
+--------------------------
+ t
+(1 row)
+
+SELECT externalized=0 AS main_doesnt_externalize FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'm';
+ main_doesnt_externalize 
+-------------------------
+ t
+(1 row)
+
+DROP TABLE toast_test;
+SELECT count(*) FROM pg_stat_toast WHERE relname = 'toast_test';
+ count 
+-------
+     0
+(1 row)
+
+DROP FUNCTION wait_for_stats();
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index 5b0c73d7e3..ec5fa7c562 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -124,7 +124,7 @@ test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion tr
 # ----------
 # Another group of parallel tests
 # ----------
-test: partition_join partition_prune reloptions hash_part indexing partition_aggregate partition_info tuplesort explain compression memoize
+test: partition_join partition_prune reloptions hash_part indexing partition_aggregate partition_info tuplesort explain compression memoize track_toast
 
 # event triggers cannot run concurrently with any test that runs DDL
 # oidjoins is read-only, though, and should run late for best coverage
diff --git a/src/test/regress/sql/track_toast.sql b/src/test/regress/sql/track_toast.sql
new file mode 100644
index 0000000000..7096719ae8
--- /dev/null
+++ b/src/test/regress/sql/track_toast.sql
@@ -0,0 +1,64 @@
+SHOW track_toast;
+SET track_toast TO on;
+SHOW track_toast;
+TABLE pg_stat_toast; -- view exists
+
+-- function to wait for counters to advance
+create function wait_for_stats() returns void as $$
+declare
+  start_time timestamptz := clock_timestamp();
+  updated1 bool;
+begin
+  -- we don't want to wait forever; loop will exit after 30 seconds
+  for i in 1 .. 300 loop
+
+    -- check to see if seqscan has been sensed
+    SELECT (st.n_tup_ins > 0) INTO updated1
+      FROM pg_stat_user_tables AS st
+     WHERE st.relname='toast_test';
+
+    exit when updated1;
+
+    -- wait a little
+    perform pg_sleep_for('100 milliseconds');
+
+    -- reset stats snapshot so we can test again
+    perform pg_stat_clear_snapshot();
+
+  end loop;
+
+  -- report time waited in postmaster log (where it won't change test output)
+  raise log 'wait_for_stats delayed % seconds',
+    extract(epoch from clock_timestamp() - start_time);
+end
+$$ language plpgsql;
+
+CREATE TABLE toast_test (cola TEXT, colb TEXT COMPRESSION lz4, colc TEXT , cold TEXT, cole TEXT);
+ALTER TABLE toast_test ALTER colc SET STORAGE EXTERNAL;
+ALTER TABLE toast_test ALTER cold SET STORAGE MAIN;
+ALTER TABLE toast_test ALTER cole SET STORAGE PLAIN;
+INSERT INTO toast_test VALUES (repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100) );
+
+-- We can't just call wait_for_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_stats();
+
+SELECT attname
+	,storagemethod
+	,externalized
+	,compressmethod
+	,compressattempts
+	,compresssuccesses
+	,compressedsize < originalsize AS compression_works
+	, total_time > 0 AS takes_time 
+FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY attname;
+SELECT compressattempts=0 AS external_doesnt_compress FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'e';
+SELECT externalized=0 AS main_doesnt_externalize FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'm';
+DROP TABLE toast_test;
+SELECT count(*) FROM pg_stat_toast WHERE relname = 'toast_test';
+DROP FUNCTION wait_for_stats();
-- 
2.32.0

From f07213d68c646ba64757e551e3587aab0ff221df Mon Sep 17 00:00:00 2001
From: "Gunnar \"Nick\" Bluth" <gunnar.bluth@pro-open.de>
Date: Tue, 4 Jan 2022 12:08:32 +0100
Subject: [PATCH v7] pg_stat_toast v7

---
 doc/src/sgml/config.sgml                      |  26 ++
 doc/src/sgml/monitoring.sgml                  | 163 ++++++++++
 doc/src/sgml/storage.sgml                     |  12 +-
 src/backend/access/table/toast_helper.c       |  44 ++-
 src/backend/catalog/system_views.sql          |  20 ++
 src/backend/postmaster/pgstat.c               | 305 +++++++++++++++++-
 src/backend/utils/adt/pgstatfuncs.c           |  72 +++++
 src/backend/utils/misc/guc.c                  |   9 +
 src/backend/utils/misc/postgresql.conf.sample |   1 +
 src/include/catalog/pg_proc.dat               |  25 ++
 src/include/pgstat.h                          | 107 ++++++
 src/test/regress/expected/rules.out           |  17 +
 src/test/regress/expected/stats.out           |  62 ++++
 src/test/regress/sql/stats.sql                |  28 ++
 14 files changed, 882 insertions(+), 9 deletions(-)

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index afbb6c35e3..b2617cc941 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -7668,6 +7668,32 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv;
       </listitem>
      </varlistentry>
 
+     <varlistentry id="guc-track-toast" xreflabel="track_toast">
+      <term><varname>track_toast</varname> (<type>boolean</type>)
+      <indexterm>
+       <primary><varname>track_toast</varname> configuration parameter</primary>
+      </indexterm>
+      </term>
+      <listitem>
+       <para>
+        Enables tracking of <link linkend="storage-toast">TOAST</link> activities.
+        Compressions and externalizations are tracked.
+        The default is <literal>off</literal>.
+        Only superusers can change this setting.
+       </para>
+
+       <note>
+        <para>
+        Be aware that this feature, depending on the amount of TOASTable columns in
+        your databases, may significantly increase the size of the statistics files
+        and the workload of the statistics collector. It is recommended to only
+        temporarily activate this to assess the right compression and storage method
+        for a column.
+        </para>
+       </note>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="guc-stats-temp-directory" xreflabel="stats_temp_directory">
       <term><varname>stats_temp_directory</varname> (<type>string</type>)
       <indexterm>
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 62f2a3332b..d2ed4e8e7d 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -610,6 +610,17 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
       yet included in <structname>pg_stat_user_functions</structname>).</entry>
      </row>
 
+     <row>
+      <entry><structname>pg_stat_toast</structname><indexterm><primary>pg_stat_toast</primary></indexterm></entry>
+      <entry>
+       One row for each column that has ever been TOASTed (compressed and/or externalized).
+       Showing the number of externalizations, compression attempts / successes, compressed and
+       uncompressed sizes etc.
+       <link linkend="monitoring-pg-stat-toast-view">
+       <structname>pg_stat_toast</structname></link> for details.
+      </entry>
+     </row>
+
      <row>
       <entry><structname>pg_stat_slru</structname><indexterm><primary>pg_stat_slru</primary></indexterm></entry>
       <entry>One row per SLRU, showing statistics of operations. See
@@ -4969,6 +4980,158 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
 
  </sect2>
 
+ <sect2 id="monitoring-pg-stat-toast-view">
+  <title><structname>pg_stat_toast</structname></title>
+
+  <indexterm>
+   <primary>pg_stat_toast</primary>
+  </indexterm>
+
+  <para>
+   The <structname>pg_stat_toast</structname> view will contain
+   one row for each column of variable size that has been TOASTed since 
+   the last statistics reset. The <xref linkend="guc-track-toast"/> parameter
+   controls whether TOAST activities are tracked or not.
+  </para>
+
+  <table id="pg-stat-toast-view" xreflabel="pg_stat_toast">
+   <title><structname>pg_stat_toast</structname> View</title>
+   <tgroup cols="1">
+    <thead>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       Column Type
+      </para>
+      <para>
+       Description
+      </para></entry>
+     </row>
+    </thead>
+
+    <tbody>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>schemaname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the schema the relation is in
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>reloid</structfield> <type>oid</type>
+      </para>
+      <para>
+       OID of the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>attnum</structfield> <type>int</type>
+      </para>
+      <para>
+       Attribute (column) number in the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>relname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>attname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the attribute (column)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>storagemethod</structfield> <type>char</type>
+      </para>
+      <para>
+       Storage method of the attribute
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>externalized</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times this attribute was externalized (pushed to TOAST relation)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressmethod</structfield> <type>char</type>
+      </para>
+      <para>
+       Current compression method of the attribute (empty means default)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressattempts</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times compression of this attribute was attempted
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compresssuccesses</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times compression of this attribute was successful
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressedsize</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total size of all compressed datums
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>originalsize</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total size of all compressed datums before compression
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>total_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Total time spent TOASTing this attribute, in microseconds.
+      </para></entry>
+     </row>
+
+    </tbody>
+   </tgroup>
+  </table>
+
+ </sect2>
+
  <sect2 id="monitoring-pg-stat-slru-view">
   <title><structname>pg_stat_slru</structname></title>
 
diff --git a/doc/src/sgml/storage.sgml b/doc/src/sgml/storage.sgml
index 7136bbe7a3..2a47922573 100644
--- a/doc/src/sgml/storage.sgml
+++ b/doc/src/sgml/storage.sgml
@@ -517,6 +517,15 @@ pages). There was no run time difference compared to an un-<acronym>TOAST</acron
 comparison table, in which all the HTML pages were cut down to 7 kB to fit.
 </para>
 
+<para>
+When you enable <xref linkend="guc-track-toast"/>, the system view
+<link linkend="monitoring-pg-stat-toast-view"><structname>pg_stat_toast</structname>
+</link> provides details on the number and effect of compression attempts,
+number of externalizations and some more useful information that enables you
+to decide if a different storage method and/or compression method would suite a
+column better.
+</para>
+
 </sect2>
 
 <sect2 id="storage-toast-inmemory">
@@ -1068,7 +1077,8 @@ data. Empty in ordinary tables.</entry>
   <type>struct varlena</type>, which includes the total length of the stored
   value and some flag bits.  Depending on the flags, the data can be either
   inline or in a <acronym>TOAST</acronym> table;
-  it might be compressed, too (see <xref linkend="storage-toast"/>).
+  it might be compressed, too (see <xref linkend="storage-toast"/> and 
+  <xref linkend="monitoring-pg-stat-toast-view"/>).
 
  </para>
  </sect2>
diff --git a/src/backend/access/table/toast_helper.c b/src/backend/access/table/toast_helper.c
index 013236b73d..d0a8ca4a1c 100644
--- a/src/backend/access/table/toast_helper.c
+++ b/src/backend/access/table/toast_helper.c
@@ -19,7 +19,9 @@
 #include "access/toast_helper.h"
 #include "access/toast_internals.h"
 #include "catalog/pg_type_d.h"
+#include "pgstat.h"
 
+extern PGDLLIMPORT bool pgstat_track_toast;
 
 /*
  * Prepare to TOAST a tuple.
@@ -226,10 +228,15 @@ toast_tuple_find_biggest_attribute(ToastTupleContext *ttc,
 void
 toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 {
-	Datum	   *value = &ttc->ttc_values[attribute];
-	Datum		new_value;
+	Datum	*value = &ttc->ttc_values[attribute];
+	Datum	new_value;
 	ToastAttrInfo *attr = &ttc->ttc_attr[attribute];
+	instr_time	start_time;
 
+	if (pgstat_track_toast)
+	{
+		INSTR_TIME_SET_CURRENT(start_time);
+	}
 	new_value = toast_compress_datum(*value, attr->tai_compression);
 
 	if (DatumGetPointer(new_value) != NULL)
@@ -239,6 +246,15 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 			pfree(DatumGetPointer(*value));
 		*value = new_value;
 		attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
+		if (pgstat_track_toast)
+		{
+			pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							attr->tai_size,
+							VARSIZE(DatumGetPointer(*value)),
+							start_time);
+		}
 		attr->tai_size = VARSIZE(DatumGetPointer(*value));
 		ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
 	}
@@ -246,6 +262,15 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 	{
 		/* incompressible, ignore on subsequent compression passes */
 		attr->tai_colflags |= TOASTCOL_INCOMPRESSIBLE;
+		if (pgstat_track_toast)
+		{
+			pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							0,
+							0,
+							start_time);
+		}
 	}
 }
 
@@ -258,6 +283,12 @@ toast_tuple_externalize(ToastTupleContext *ttc, int attribute, int options)
 	Datum	   *value = &ttc->ttc_values[attribute];
 	Datum		old_value = *value;
 	ToastAttrInfo *attr = &ttc->ttc_attr[attribute];
+	instr_time	start_time;
+
+	if (pgstat_track_toast)
+	{
+		INSTR_TIME_SET_CURRENT(start_time);
+	}
 
 	attr->tai_colflags |= TOASTCOL_IGNORE;
 	*value = toast_save_datum(ttc->ttc_rel, old_value, attr->tai_oldexternal,
@@ -266,6 +297,15 @@ toast_tuple_externalize(ToastTupleContext *ttc, int attribute, int options)
 		pfree(DatumGetPointer(old_value));
 	attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
 	ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
+	if (pgstat_track_toast)
+	{
+		pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							true,
+							false,
+							0,
+							0,
+							start_time);
+}
 }
 
 /*
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 61b515cdb8..3de3025488 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -1039,6 +1039,26 @@ CREATE VIEW pg_stat_user_functions AS
     WHERE P.prolang != 12  -- fast check to eliminate built-in functions
           AND pg_stat_get_function_calls(P.oid) IS NOT NULL;
 
+
+CREATE OR REPLACE VIEW pg_stat_toast AS
+ SELECT 
+    n.nspname AS schemaname,
+    a.attrelid AS reloid,
+    a.attnum AS attnum,
+    c.relname AS relname,
+    a.attname AS attname,
+    attstorage AS storagemethod,
+    pg_stat_get_toast_externalizations(a.attrelid,a.attnum) AS externalized,
+    attcompression AS compressmethod,
+    pg_stat_get_toast_compressions(a.attrelid,a.attnum) AS compressattempts,
+    pg_stat_get_toast_compressionsuccesses(a.attrelid,a.attnum) AS compresssuccesses,
+    pg_stat_get_toast_compressedsizesum(a.attrelid,a.attnum) AS compressedsize,
+    pg_stat_get_toast_originalsizesum(a.attrelid,a.attnum) AS originalsize,
+    pg_stat_get_toast_total_time(a.attrelid,a.attnum) AS total_time
+   FROM pg_attribute a
+   JOIN pg_class c ON c.oid = a.attrelid
+   LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
+  WHERE pg_stat_get_toast_externalizations(a.attrelid,a.attnum) IS NOT NULL;
 CREATE VIEW pg_stat_xact_user_functions AS
     SELECT
             P.oid AS funcid,
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 7264d2c727..68aa770d21 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -106,6 +106,7 @@
 #define PGSTAT_DB_HASH_SIZE		16
 #define PGSTAT_TAB_HASH_SIZE	512
 #define PGSTAT_FUNCTION_HASH_SIZE	512
+#define PGSTAT_TOAST_HASH_SIZE	64
 #define PGSTAT_SUBWORKER_HASH_SIZE	32
 #define PGSTAT_REPLSLOT_HASH_SIZE	32
 
@@ -116,6 +117,7 @@
  */
 bool		pgstat_track_counts = false;
 int			pgstat_track_functions = TRACK_FUNC_OFF;
+bool		pgstat_track_toast = false;
 
 /* ----------
  * Built from GUC parameter
@@ -228,6 +230,19 @@ static HTAB *pgStatFunctions = NULL;
  */
 static bool have_function_stats = false;
 
+/*
+ * Backends store per-toast-column info that's waiting to be sent to the collector
+ * in this hash table (indexed by column's PgStat_BackendAttrIdentifier).
+ */
+static HTAB *pgStatToastActions = NULL;
+
+
+/*
+ * Indicates if backend has some toast stats that it hasn't yet
+ * sent to the collector.
+ */
+static bool have_toast_stats = false;
+
 /*
  * Tuple insertion/deletion counts for an open transaction can't be propagated
  * into PgStat_TableStatus counters until we know if it is going to commit
@@ -328,7 +343,7 @@ static PgStat_StatSubWorkerEntry *pgstat_get_subworker_entry(PgStat_StatDBEntry
 static void pgstat_write_statsfiles(bool permanent, bool allDbs);
 static void pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent);
 static HTAB *pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep);
-static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 									 HTAB *subworkerhash, bool permanent);
 static void backend_read_statsfile(void);
 
@@ -340,6 +355,7 @@ static void pgstat_reset_replslot(PgStat_StatReplSlotEntry *slotstats, Timestamp
 
 static void pgstat_send_tabstat(PgStat_MsgTabstat *tsmsg, TimestampTz now);
 static void pgstat_send_funcstats(void);
+static void pgstat_send_toaststats(void);
 static void pgstat_send_slru(void);
 static void pgstat_send_subscription_purge(PgStat_MsgSubscriptionPurge *msg);
 static HTAB *pgstat_collect_oids(Oid catalogid, AttrNumber anum_oid);
@@ -373,6 +389,7 @@ static void pgstat_recv_wal(PgStat_MsgWal *msg, int len);
 static void pgstat_recv_slru(PgStat_MsgSLRU *msg, int len);
 static void pgstat_recv_funcstat(PgStat_MsgFuncstat *msg, int len);
 static void pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len);
+static void pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len);
 static void pgstat_recv_recoveryconflict(PgStat_MsgRecoveryConflict *msg, int len);
 static void pgstat_recv_deadlock(PgStat_MsgDeadlock *msg, int len);
 static void pgstat_recv_checksum_failure(PgStat_MsgChecksumFailure *msg, int len);
@@ -891,7 +908,7 @@ pgstat_report_stat(bool disconnect)
 		pgStatXactCommit == 0 && pgStatXactRollback == 0 &&
 		pgWalUsage.wal_records == prevWalUsage.wal_records &&
 		WalStats.m_wal_write == 0 && WalStats.m_wal_sync == 0 &&
-		!have_function_stats && !disconnect)
+		!have_function_stats && !have_toast_stats && !disconnect)
 		return;
 
 	/*
@@ -983,6 +1000,9 @@ pgstat_report_stat(bool disconnect)
 	/* Now, send function statistics */
 	pgstat_send_funcstats();
 
+	/* Now, send TOAST statistics */
+	pgstat_send_toaststats();
+
 	/* Send WAL statistics */
 	pgstat_send_wal(true);
 
@@ -1116,6 +1136,63 @@ pgstat_send_funcstats(void)
 	have_function_stats = false;
 }
 
+/*
+ * Subroutine for pgstat_report_stat: populate and send a toast stat message
+ */
+static void
+pgstat_send_toaststats(void)
+{
+	static const PgStat_ToastCounts all_zeroes;
+
+	PgStat_MsgToaststat msg;
+	PgStat_BackendToastEntry *entry;
+	HASH_SEQ_STATUS tstat;
+
+	if (pgStatToastActions == NULL)
+		return;
+
+	pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_TOASTSTAT);
+	msg.m_databaseid = MyDatabaseId;
+	msg.m_nentries = 0;
+
+	hash_seq_init(&tstat, pgStatToastActions);
+	while ((entry = (PgStat_BackendToastEntry *) hash_seq_search(&tstat)) != NULL)
+	{
+		PgStat_ToastEntry *m_ent;
+
+		/* Skip it if no counts accumulated since last time */
+		if (memcmp(&entry->t_counts, &all_zeroes,
+				   sizeof(PgStat_ToastCounts)) == 0)
+			continue;
+
+		/* need to convert format of time accumulators */
+		m_ent = &msg.m_entry[msg.m_nentries];
+		m_ent->attr = entry->attr;
+		m_ent->t_numexternalized = entry->t_counts.t_numexternalized;
+		m_ent->t_numcompressed = entry->t_counts.t_numcompressed;
+		m_ent->t_numcompressionsuccess = entry->t_counts.t_numcompressionsuccess;
+		m_ent->t_size_orig = entry->t_counts.t_size_orig;
+		m_ent->t_size_compressed = entry->t_counts.t_size_compressed;
+		m_ent->t_comp_time = INSTR_TIME_GET_MICROSEC(entry->t_counts.t_comp_time);
+
+		if (++msg.m_nentries >= PGSTAT_NUM_TOASTENTRIES)
+		{
+			pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+						msg.m_nentries * sizeof(PgStat_ToastEntry));
+			msg.m_nentries = 0;
+		}
+
+		/* reset the entry's counts */
+		MemSet(&entry->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	if (msg.m_nentries > 0)
+		pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+					msg.m_nentries * sizeof(PgStat_ToastEntry));
+
+	have_toast_stats = false;
+}
+
 
 /* ----------
  * pgstat_vacuum_stat() -
@@ -2151,6 +2228,72 @@ pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu, bool finalize)
 	have_function_stats = true;
 }
 
+/*
+ * Report TOAST activity
+ * Called by toast_helper functions.
+ */
+void
+pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							instr_time start_time)
+{
+	PgStat_BackendAttrIdentifier toastattr = { relid, attr };
+	PgStat_BackendToastEntry *htabent;
+	instr_time	time_spent;
+	bool		found;
+
+	if (pgStatSock == PGINVALID_SOCKET || !pgstat_track_toast)
+		return;
+
+	INSTR_TIME_SET_CURRENT(time_spent);
+	INSTR_TIME_SUBTRACT(time_spent, start_time);
+
+	if (!pgStatToastActions)
+	{
+		/* First time through - initialize toast stat table */
+		HASHCTL		hash_ctl;
+
+		hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+		hash_ctl.entrysize = sizeof(PgStat_BackendToastEntry);
+		pgStatToastActions = hash_create("TOAST stat entries",
+									  PGSTAT_TOAST_HASH_SIZE,
+									  &hash_ctl,
+									  HASH_ELEM | HASH_BLOBS);
+	}
+
+	/* Get the stats entry for this TOAST attribute, create if necessary */
+	htabent = hash_search(pgStatToastActions, &toastattr,
+						  HASH_ENTER, &found);
+	if (!found)
+	{
+		MemSet(&htabent->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	/* update counters */
+	if (externalized)
+	{
+		htabent->t_counts.t_numexternalized++;
+	}
+	if (compressed)
+	{
+		htabent->t_counts.t_numcompressed++;
+		htabent->t_counts.t_size_orig+=old_size;
+		if (new_size)
+		{
+			htabent->t_counts.t_numcompressionsuccess++;
+			htabent->t_counts.t_size_compressed+=new_size;
+		}
+	}
+	/* record time spent */
+	INSTR_TIME_ADD(htabent->t_counts.t_comp_time, time_spent);
+
+	/* indicate that we have something to send */
+	have_toast_stats = true;
+}
+
 
 /* ----------
  * pgstat_initstats() -
@@ -3028,6 +3171,35 @@ pgstat_fetch_stat_subworker_entry(Oid subid, Oid subrelid)
 	return wentry;
 }
 
+/* ----------
+ * pgstat_fetch_stat_toastentry() -
+ *
+ *	Support function for the SQL-callable pgstat* functions. Returns
+ *	the collected statistics for one TOAST attribute or NULL.
+ * ----------
+ */
+PgStat_StatToastEntry *
+pgstat_fetch_stat_toastentry(Oid rel_id, int attr)
+{
+	PgStat_StatDBEntry *dbentry;
+	PgStat_BackendAttrIdentifier toast_id = { rel_id, attr };
+	PgStat_StatToastEntry *toastentry = NULL;
+
+	/* load the stats file if needed */
+	backend_read_statsfile();
+
+	/* Lookup our database, then find the requested TOAST activity stats.  */
+	dbentry = pgstat_fetch_stat_dbentry(MyDatabaseId);
+	if (dbentry != NULL && dbentry->toastactivity != NULL)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &toast_id,
+														 HASH_FIND, NULL);
+	}
+
+	return toastentry;
+}
+
 /*
  * ---------
  * pgstat_fetch_stat_archiver() -
@@ -3708,6 +3880,10 @@ PgstatCollectorMain(int argc, char *argv[])
 					pgstat_recv_funcpurge(&msg.msg_funcpurge, len);
 					break;
 
+				case PGSTAT_MTYPE_TOASTSTAT:
+					pgstat_recv_toaststat(&msg.msg_toaststat, len);
+					break;
+
 				case PGSTAT_MTYPE_RECOVERYCONFLICT:
 					pgstat_recv_recoveryconflict(&msg.msg_recoveryconflict,
 												 len);
@@ -3852,6 +4028,14 @@ reset_dbentry_counters(PgStat_StatDBEntry *dbentry)
 									  PGSTAT_SUBWORKER_HASH_SIZE,
 									  &hash_ctl,
 									  HASH_ELEM | HASH_BLOBS);
+
+	hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+	hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+	dbentry->toastactivity = hash_create("Per-database TOAST",
+									 PGSTAT_TOAST_HASH_SIZE,
+									 &hash_ctl,
+									 HASH_ELEM | HASH_BLOBS);
+
 }
 
 /*
@@ -4059,8 +4243,8 @@ pgstat_write_statsfiles(bool permanent, bool allDbs)
 	while ((dbentry = (PgStat_StatDBEntry *) hash_seq_search(&hstat)) != NULL)
 	{
 		/*
-		 * Write out the table, function, and subscription-worker stats for
-		 * this DB into the appropriate per-DB stat file, if required.
+		 * Write out the table, function, TOAST and subscription-worker stats for this DB into the
+		 * appropriate per-DB stat file, if required.
 		 */
 		if (allDbs || pgstat_db_requested(dbentry->databaseid))
 		{
@@ -4175,9 +4359,11 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 	HASH_SEQ_STATUS tstat;
 	HASH_SEQ_STATUS fstat;
 	HASH_SEQ_STATUS sstat;
+	HASH_SEQ_STATUS ostat;
 	PgStat_StatTabEntry *tabentry;
 	PgStat_StatFuncEntry *funcentry;
 	PgStat_StatSubWorkerEntry *subwentry;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpout;
 	int32		format_id;
 	Oid			dbid = dbentry->databaseid;
@@ -4243,6 +4429,17 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 		(void) rc;				/* we'll check for error with ferror */
 	}
 
+	/*
+	 * Walk through the database's TOAST stats table.
+	 */
+	hash_seq_init(&ostat, dbentry->toastactivity);
+	while ((toastentry = (PgStat_StatToastEntry *) hash_seq_search(&ostat)) != NULL)
+	{
+		fputc('O', fpout);
+		rc = fwrite(toastentry, sizeof(PgStat_StatToastEntry), 1, fpout);
+		(void) rc;				/* we'll check for error with ferror */
+	}
+
 	/*
 	 * No more output to be done. Close the temp file and replace the old
 	 * pgstat.stat with it.  The ferror() check replaces testing for error
@@ -4483,6 +4680,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 				dbentry->tables = NULL;
 				dbentry->functions = NULL;
 				dbentry->subworkers = NULL;
+				dbentry->toastactivity = NULL;
 
 				/*
 				 * In the collector, disregard the timestamp we read from the
@@ -4528,6 +4726,14 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 												  &hash_ctl,
 												  HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
 
+				hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+				hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+				hash_ctl.hcxt = pgStatLocalContext;
+				dbentry->toastactivity = hash_create("Per-database toast information",
+												 PGSTAT_TOAST_HASH_SIZE,
+												 &hash_ctl,
+												 HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
+
 				/*
 				 * If requested, read the data from the database-specific
 				 * file.  Otherwise we just leave the hashtables empty.
@@ -4536,6 +4742,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 					pgstat_read_db_statsfile(dbentry->databaseid,
 											 dbentry->tables,
 											 dbentry->functions,
+											 dbentry->toastactivity,
 											 dbentry->subworkers,
 											 permanent);
 
@@ -4620,7 +4827,7 @@ done:
  * ----------
  */
 static void
-pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 						 HTAB *subworkerhash, bool permanent)
 {
 	PgStat_StatTabEntry *tabentry;
@@ -4629,6 +4836,8 @@ pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
 	PgStat_StatFuncEntry *funcentry;
 	PgStat_StatSubWorkerEntry subwbuf;
 	PgStat_StatSubWorkerEntry *subwentry;
+	PgStat_StatToastEntry toastbuf;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpin;
 	int32		format_id;
 	bool		found;
@@ -4777,6 +4986,32 @@ pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
 				memcpy(subwentry, &subwbuf, sizeof(subwbuf));
 				break;
 
+
+				/*
+				 * 'O'	A PgStat_StatToastEntry follows (tOast)
+				 */
+			case 'O':
+				if (fread(&toastbuf, 1, sizeof(PgStat_StatToastEntry),
+						  fpin) != sizeof(PgStat_StatToastEntry))
+				{
+					ereport(pgStatRunningInCollector ? LOG : WARNING,
+							(errmsg("corrupted statistics file \"%s\"",
+									statfile)));
+					goto done;
+				}
+
+				/*
+				 * Skip if TOAST data not wanted.
+				 */
+				if (toasthash == NULL)
+					break;
+
+				toastentry = (PgStat_StatToastEntry *) hash_search(toasthash,
+																 (void *) &toastbuf.t_id,
+																 HASH_ENTER, &found);
+				memcpy(toastentry, &toastbuf, sizeof(toastbuf));
+				break;
+
 				/*
 				 * 'E'	The EOF marker of a complete stats file.
 				 */
@@ -5452,6 +5687,8 @@ pgstat_recv_dropdb(PgStat_MsgDropdb *msg, int len)
 			hash_destroy(dbentry->functions);
 		if (dbentry->subworkers != NULL)
 			hash_destroy(dbentry->subworkers);
+		if (dbentry->toastactivity != NULL)
+			hash_destroy(dbentry->toastactivity);
 
 		if (hash_search(pgStatDBHash,
 						(void *) &dbid,
@@ -5491,10 +5728,12 @@ pgstat_recv_resetcounter(PgStat_MsgResetcounter *msg, int len)
 		hash_destroy(dbentry->functions);
 	if (dbentry->subworkers != NULL)
 		hash_destroy(dbentry->subworkers);
-
+	if (dbentry->toastactivity != NULL)
+		hash_destroy(dbentry->toastactivity);
 	dbentry->tables = NULL;
 	dbentry->functions = NULL;
 	dbentry->subworkers = NULL;
+	dbentry->toastactivity = NULL;
 
 	/*
 	 * Reset database-level stats, too.  This creates empty hash tables for
@@ -6152,6 +6391,60 @@ pgstat_recv_subscription_purge(PgStat_MsgSubscriptionPurge *msg, int len)
 	}
 }
 
+/* ----------
+ * pgstat_recv_toaststat() -
+ *
+ *	Count what the backend has done.
+ * ----------
+ */
+static void
+pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len)
+{
+	PgStat_ToastEntry *toastmsg = &(msg->m_entry[0]);
+	PgStat_StatDBEntry *dbentry;
+	PgStat_StatToastEntry *toastentry;
+	int			i;
+	bool		found;
+
+	dbentry = pgstat_get_db_entry(msg->m_databaseid, true);
+
+	/*
+	 * Process all TOAST entries in the message.
+	 */
+	for (i = 0; i < msg->m_nentries; i++, toastmsg++)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &(toastmsg->attr),
+														 HASH_ENTER, &found);
+
+		if (!found)
+		{
+			/*
+			 * If it's a new entry, initialize counters to the values
+			 * we just got.
+			 */
+			toastentry->t_numexternalized = toastmsg->t_numexternalized;
+			toastentry->t_numcompressed = toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess = toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_orig = toastmsg->t_size_orig;
+			toastentry->t_size_compressed = toastmsg->t_size_compressed;
+			toastentry->t_comp_time = toastmsg->t_comp_time;
+		}
+		else
+		{
+			/*
+			 * Otherwise add the values to the existing entry.
+			 */
+			toastentry->t_numexternalized += toastmsg->t_numexternalized;
+			toastentry->t_numcompressed += toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess += toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_orig += toastmsg->t_size_orig;
+			toastentry->t_size_compressed += toastmsg->t_size_compressed;
+			toastentry->t_comp_time += toastmsg->t_comp_time;
+		}
+	}
+}
+
 /* ----------
  * pgstat_recv_subworker_error() -
  *
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index f529c1561a..8b40c43626 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -410,6 +410,78 @@ pg_stat_get_function_self_time(PG_FUNCTION_ARGS)
 	PG_RETURN_FLOAT8(((double) funcentry->f_self_time) / 1000.0);
 }
 
+Datum
+pg_stat_get_toast_externalizations(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numexternalized);
+}
+
+Datum
+pg_stat_get_toast_compressions(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressed);
+}
+
+Datum
+pg_stat_get_toast_compressionsuccesses(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressionsuccess);
+}
+
+Datum
+pg_stat_get_toast_originalsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_orig);
+}
+
+Datum
+pg_stat_get_toast_compressedsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_compressed);
+}
+
+Datum
+pg_stat_get_toast_total_time(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_comp_time);
+}
+
 Datum
 pg_stat_get_backend_idset(PG_FUNCTION_ARGS)
 {
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index f9504d3aec..f7ff934d4e 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -1538,6 +1538,15 @@ static struct config_bool ConfigureNamesBool[] =
 		true,
 		NULL, NULL, NULL
 	},
+	{
+		{"track_toast", PGC_SUSET, STATS_COLLECTOR,
+			gettext_noop("Collects statistics on TOAST activity."),
+			NULL
+		},
+		&pgstat_track_toast,
+		false,
+		NULL, NULL, NULL
+	},
 	{
 		{"track_io_timing", PGC_SUSET, STATS_COLLECTOR,
 			gettext_noop("Collects timing statistics for database I/O activity."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index a1acd46b61..12f4bb1a38 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -607,6 +607,7 @@
 #track_io_timing = off
 #track_wal_io_timing = off
 #track_functions = none			# none, pl, all
+#track_toast = off
 #stats_temp_directory = 'pg_stat_tmp'
 
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 4d992dc224..22c34b96a6 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5668,6 +5668,31 @@
   proparallel => 'r', prorettype => 'float8', proargtypes => 'oid',
   prosrc => 'pg_stat_get_function_self_time' },
 
+{ oid => '9700', descr => 'statistics: number of TOAST externalizations',
+  proname => 'pg_stat_get_toast_externalizations', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_externalizations' },
+{ oid => '9701', descr => 'statistics: number of TOAST compressions',
+  proname => 'pg_stat_get_toast_compressions', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressions' },
+  { oid => '9702', descr => 'statistics: number of successful TOAST compressions',
+  proname => 'pg_stat_get_toast_compressionsuccesses', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressionsuccesses' },
+{ oid => '9703', descr => 'statistics: total original size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_originalsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_originalsizesum' },
+{ oid => '9704', descr => 'statistics: total compressed size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_compressedsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressedsizesum' },
+{ oid => '9705', descr => 'statistics: total time spend TOASTing data',
+  proname => 'pg_stat_get_toast_total_time', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_total_time' },
+
 { oid => '3037',
   descr => 'statistics: number of scans done for table/index in current transaction',
   proname => 'pg_stat_get_xact_numscans', provolatile => 'v',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 5b51b58e5a..b65f08de40 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -86,6 +86,7 @@ typedef enum StatMsgType
 	PGSTAT_MTYPE_DISCONNECT,
 	PGSTAT_MTYPE_SUBSCRIPTIONPURGE,
 	PGSTAT_MTYPE_SUBWORKERERROR,
+	PGSTAT_MTYPE_TOASTSTAT,
 } StatMsgType;
 
 /* ----------
@@ -733,6 +734,80 @@ typedef struct PgStat_MsgDisconnect
 	SessionEndType m_cause;
 } PgStat_MsgDisconnect;
 
+/* ----------
+ * PgStat_BackendAttrIdentifier	Identifier for a single attribute/column (OID + attr)
+ * Used as a hashable identifier for (e.g.) TOAST columns
+ * ----------
+ */
+typedef struct PgStat_BackendAttrIdentifier
+{
+	Oid			relid;
+	int			attr;
+} PgStat_BackendAttrIdentifier;
+
+/* ----------
+ * PgStat_ToastCounts	The actual per-TOAST counts kept by a backend
+ *
+ * This struct should contain only actual event counters, because we memcmp
+ * it against zeroes to detect whether there are any counts to transmit.
+ *
+ * Note that the time counters are in instr_time format here.  We convert to
+ * microseconds in PgStat_Counter format when transmitting to the collector.
+ * ----------
+ */
+typedef struct PgStat_ToastCounts
+{
+	PgStat_Counter	t_numexternalized;
+	PgStat_Counter	t_numcompressed;
+	PgStat_Counter	t_numcompressionsuccess;
+	uint64		t_size_orig;
+	uint64		t_size_compressed;
+	instr_time	t_comp_time;
+} PgStat_ToastCounts;
+
+/* ----------
+ * PgStat_BackendToastEntry	Entry in backend's per-toast-attr hash table
+ * ----------
+ */
+typedef struct PgStat_BackendToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_ToastCounts 		t_counts;
+} PgStat_BackendToastEntry;
+
+/* ----------
+ * PgStat_ToastEntry			Per-TOAST-column info in a MsgToaststat
+ * ----------
+ */
+typedef struct PgStat_ToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_Counter 			t_numexternalized;
+	PgStat_Counter 			t_numcompressed;
+	PgStat_Counter 			t_numcompressionsuccess;
+	uint64		   		t_size_orig;
+	uint64		   		t_size_compressed;
+	PgStat_Counter			t_comp_time;	/* time in microseconds */
+} PgStat_ToastEntry;
+
+/* ----------
+ * PgStat_MsgToaststat			Sent by the backend to report function
+ *								usage statistics.
+ * ----------
+ */
+#define PGSTAT_NUM_TOASTENTRIES	\
+	((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - sizeof(int))  \
+	 / sizeof(PgStat_ToastEntry))
+
+typedef struct PgStat_MsgToaststat
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+	int			m_nentries;
+	PgStat_ToastEntry m_entry[PGSTAT_NUM_TOASTENTRIES];
+} PgStat_MsgToaststat;
+
+
 /* ----------
  * PgStat_Msg					Union over all possible messages.
  * ----------
@@ -760,6 +835,7 @@ typedef union PgStat_Msg
 	PgStat_MsgSLRU msg_slru;
 	PgStat_MsgFuncstat msg_funcstat;
 	PgStat_MsgFuncpurge msg_funcpurge;
+	PgStat_MsgToaststat msg_toaststat;
 	PgStat_MsgRecoveryConflict msg_recoveryconflict;
 	PgStat_MsgDeadlock msg_deadlock;
 	PgStat_MsgTempFile msg_tempfile;
@@ -833,6 +909,7 @@ typedef struct PgStat_StatDBEntry
 	HTAB	   *tables;
 	HTAB	   *functions;
 	HTAB	   *subworkers;
+	HTAB	   *toastactivity;
 } PgStat_StatDBEntry;
 
 
@@ -1022,6 +1099,22 @@ typedef struct PgStat_StatSubWorkerEntry
 	char		last_error_message[PGSTAT_SUBWORKERERROR_MSGLEN];
 } PgStat_StatSubWorkerEntry;
 
+/* ----------
+ * PgStat_StatToastEntry			The collector's data per TOAST attribute
+ * ----------
+ */
+typedef struct PgStat_StatToastEntry
+{
+	PgStat_BackendAttrIdentifier t_id;
+	PgStat_Counter t_numexternalized;
+	PgStat_Counter t_numcompressed;
+	PgStat_Counter t_numcompressionsuccess;
+	uint64		   t_size_orig;
+	uint64		   t_size_compressed;
+	PgStat_Counter t_comp_time;	/* time in microseconds */
+} PgStat_StatToastEntry;
+
+
 /*
  * Working state needed to accumulate per-function-call timing statistics.
  */
@@ -1045,6 +1138,7 @@ typedef struct PgStat_FunctionCallUsage
  */
 extern PGDLLIMPORT bool pgstat_track_counts;
 extern PGDLLIMPORT int pgstat_track_functions;
+extern PGDLLIMPORT bool pgstat_track_toast;
 extern char *pgstat_stat_directory;
 extern char *pgstat_stat_tmpname;
 extern char *pgstat_stat_filename;
@@ -1196,12 +1290,22 @@ extern void pgstat_count_heap_delete(Relation rel);
 extern void pgstat_count_truncate(Relation rel);
 extern void pgstat_update_heap_dead_tuples(Relation rel, int delta);
 
+extern void pgstat_count_toast_insert(Relation rel, PgStat_Counter n);
+
 struct FunctionCallInfoBaseData;
 extern void pgstat_init_function_usage(struct FunctionCallInfoBaseData *fcinfo,
 									   PgStat_FunctionCallUsage *fcu);
 extern void pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu,
 									  bool finalize);
 
+extern void
+pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							instr_time start_time);
+
 extern void AtEOXact_PgStat(bool isCommit, bool parallel);
 extern void AtEOSubXact_PgStat(bool isCommit, int nestDepth);
 
@@ -1228,9 +1332,12 @@ extern PgStat_StatTabEntry *pgstat_fetch_stat_tabentry(Oid relid);
 extern PgStat_StatFuncEntry *pgstat_fetch_stat_funcentry(Oid funcid);
 extern PgStat_StatSubWorkerEntry *pgstat_fetch_stat_subworker_entry(Oid subid,
 																	Oid subrelid);
+extern PgStat_StatToastEntry *pgstat_fetch_stat_toastentry(Oid rel_id, int attr);
+extern PgStat_ArchiverStats *pgstat_fetch_stat_archiver(void);
 extern PgStat_ArchiverStats *pgstat_fetch_stat_archiver(void);
 extern PgStat_BgWriterStats *pgstat_fetch_stat_bgwriter(void);
 extern PgStat_CheckpointerStats *pgstat_fetch_stat_checkpointer(void);
+
 extern PgStat_GlobalStats *pgstat_fetch_global(void);
 extern PgStat_WalStats *pgstat_fetch_stat_wal(void);
 extern PgStat_SLRUStats *pgstat_fetch_slru(void);
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index b58b062b10..2b49bebcb8 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -2147,6 +2147,23 @@ pg_stat_sys_tables| SELECT pg_stat_all_tables.relid,
     pg_stat_all_tables.autoanalyze_count
    FROM pg_stat_all_tables
   WHERE ((pg_stat_all_tables.schemaname = ANY (ARRAY['pg_catalog'::name, 'information_schema'::name])) OR (pg_stat_all_tables.schemaname ~ '^pg_toast'::text));
+pg_stat_toast| SELECT n.nspname AS schemaname,
+    a.attrelid AS reloid,
+    a.attnum,
+    c.relname,
+    a.attname,
+    a.attstorage AS storagemethod,
+    pg_stat_get_toast_externalizations(a.attrelid, (a.attnum)::integer) AS externalized,
+    a.attcompression AS compressmethod,
+    pg_stat_get_toast_compressions(a.attrelid, (a.attnum)::integer) AS compressattempts,
+    pg_stat_get_toast_compressionsuccesses(a.attrelid, (a.attnum)::integer) AS compresssuccesses,
+    pg_stat_get_toast_compressedsizesum(a.attrelid, (a.attnum)::integer) AS compressedsize,
+    pg_stat_get_toast_originalsizesum(a.attrelid, (a.attnum)::integer) AS originalsize,
+    pg_stat_get_toast_total_time(a.attrelid, (a.attnum)::integer) AS total_time
+   FROM ((pg_attribute a
+     JOIN pg_class c ON ((c.oid = a.attrelid)))
+     LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace)))
+  WHERE (pg_stat_get_toast_externalizations(a.attrelid, (a.attnum)::integer) IS NOT NULL);
 pg_stat_user_functions| SELECT p.oid AS funcid,
     n.nspname AS schemaname,
     p.proname AS funcname,
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 3e9ab0915f..880380aafa 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -11,6 +11,32 @@ SHOW track_counts;  -- must be on
  on
 (1 row)
 
+-- prepare and fill the pg_stat_toast table now:
+SHOW track_toast;
+ track_toast 
+-------------
+ off
+(1 row)
+
+SET track_toast TO on;
+SHOW track_toast;
+ track_toast 
+-------------
+ on
+(1 row)
+
+TABLE pg_stat_toast; -- view exists
+ schemaname | reloid | attnum | relname | attname | storagemethod | externalized | compressmethod | compressattempts | compresssuccesses | compressedsize | originalsize | total_time 
+------------+--------+--------+---------+---------+---------------+--------------+----------------+------------------+-------------------+----------------+--------------+------------
+(0 rows)
+
+CREATE TABLE toast_test (cola TEXT, colb TEXT, colc TEXT , cold TEXT);
+ALTER TABLE toast_test ALTER colb SET STORAGE EXTERNAL;
+ALTER TABLE toast_test ALTER colc SET STORAGE MAIN;
+ALTER TABLE toast_test ALTER cold SET STORAGE PLAIN;
+INSERT INTO toast_test VALUES (repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100) );
+-- make sure we don't interfere with the other tests:
+SET track_toast TO off;
 -- ensure that both seqscan and indexscan plans are allowed
 SET enable_seqscan TO on;
 SET enable_indexscan TO on;
@@ -252,4 +278,40 @@ SELECT pg_stat_get_tuples_hot_updated('brin_hot'::regclass::oid);
 
 DROP TABLE brin_hot;
 DROP FUNCTION wait_for_hot_stats();
+-- now check that the track_toast stuff worked:
+SELECT attname
+	,storagemethod
+	,externalized
+	,compressmethod
+	,compressattempts
+	,compresssuccesses
+	,compressedsize < originalsize AS compression_works
+	, total_time > 0 AS takes_time 
+FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY attname;
+ attname | storagemethod | externalized | compressmethod | compressattempts | compresssuccesses | compression_works | takes_time 
+---------+---------------+--------------+----------------+------------------+-------------------+-------------------+------------
+ cola    | x             |            1 |                |                1 |                 1 | t                 | t
+ colb    | e             |            1 |                |                0 |                 0 | f                 | t
+ colc    | m             |            0 |                |                1 |                 1 | t                 | t
+(3 rows)
+
+SELECT compressattempts=0 AS external_doesnt_compress FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'e';
+ external_doesnt_compress 
+--------------------------
+ t
+(1 row)
+
+SELECT externalized=0 AS main_doesnt_externalize FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'm';
+ main_doesnt_externalize 
+-------------------------
+ t
+(1 row)
+
+DROP TABLE toast_test;
+SELECT count(*) FROM pg_stat_toast WHERE relname = 'toast_test';
+ count 
+-------
+     0
+(1 row)
+
 -- End of Stats Test
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index 82e6f24c39..ba462537f6 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -8,6 +8,20 @@
 -- conditio sine qua non
 SHOW track_counts;  -- must be on
 
+-- prepare and fill the pg_stat_toast table now:
+SHOW track_toast;
+SET track_toast TO on;
+SHOW track_toast;
+TABLE pg_stat_toast; -- view exists
+
+CREATE TABLE toast_test (cola TEXT, colb TEXT, colc TEXT , cold TEXT);
+ALTER TABLE toast_test ALTER colb SET STORAGE EXTERNAL;
+ALTER TABLE toast_test ALTER colc SET STORAGE MAIN;
+ALTER TABLE toast_test ALTER cold SET STORAGE PLAIN;
+INSERT INTO toast_test VALUES (repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100) );
+-- make sure we don't interfere with the other tests:
+SET track_toast TO off;
+
 -- ensure that both seqscan and indexscan plans are allowed
 SET enable_seqscan TO on;
 SET enable_indexscan TO on;
@@ -225,5 +239,19 @@ SELECT pg_stat_get_tuples_hot_updated('brin_hot'::regclass::oid);
 DROP TABLE brin_hot;
 DROP FUNCTION wait_for_hot_stats();
 
+-- now check that the track_toast stuff worked:
+SELECT attname
+	,storagemethod
+	,externalized
+	,compressmethod
+	,compressattempts
+	,compresssuccesses
+	,compressedsize < originalsize AS compression_works
+	, total_time > 0 AS takes_time 
+FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY attname;
+SELECT compressattempts=0 AS external_doesnt_compress FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'e';
+SELECT externalized=0 AS main_doesnt_externalize FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'm';
+DROP TABLE toast_test;
+SELECT count(*) FROM pg_stat_toast WHERE relname = 'toast_test';
 
 -- End of Stats Test
-- 
2.32.0

 doc/src/sgml/config.sgml                      |  26 +++
 doc/src/sgml/monitoring.sgml                  | 163 ++++++++++++++
 doc/src/sgml/storage.sgml                     |  12 +-
 src/backend/access/table/toast_helper.c       |  40 ++++
 src/backend/catalog/system_views.sql          |  20 ++
 src/backend/postmaster/pgstat.c               | 302 +++++++++++++++++++++++++-
 src/backend/utils/adt/pgstatfuncs.c           |  72 ++++++
 src/backend/utils/misc/guc.c                  |   9 +
 src/backend/utils/misc/postgresql.conf.sample |   1 +
 src/include/catalog/pg_proc.dat               |  25 +++
 src/include/pgstat.h                          | 107 ++++++++-
 src/test/regress/expected/rules.out           |  17 ++
 src/test/regress/expected/stats.out           |  62 ++++++
 src/test/regress/sql/stats.sql                |  28 +++
 14 files changed, 877 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 7ed8c82a9d..adbd516373 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -7889,6 +7889,32 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv;
       </listitem>
      </varlistentry>
 
+     <varlistentry id="guc-track-toast" xreflabel="track_toast">
+      <term><varname>track_toast</varname> (<type>boolean</type>)
+      <indexterm>
+       <primary><varname>track_toast</varname> configuration parameter</primary>
+      </indexterm>
+      </term>
+      <listitem>
+       <para>
+        Enables tracking of <link linkend="storage-toast">TOAST</link> activities.
+        Compressions and externalizations are tracked.
+        The default is <literal>off</literal>.
+        Only superusers can change this setting.
+       </para>
+
+       <note>
+        <para>
+        Be aware that this feature, depending on the amount of TOASTable columns in
+        your databases, may significantly increase the size of the statistics files
+        and the workload of the statistics collector. It is recommended to only
+        temporarily activate this to assess the right compression and storage method
+        for a column.
+        </para>
+       </note>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="guc-stats-temp-directory" xreflabel="stats_temp_directory">
       <term><varname>stats_temp_directory</varname> (<type>string</type>)
       <indexterm>
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 9fb62fec8e..06258e777a 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -610,6 +610,17 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
       yet included in <structname>pg_stat_user_functions</structname>).</entry>
      </row>
 
+     <row>
+      <entry><structname>pg_stat_toast</structname><indexterm><primary>pg_stat_toast</primary></indexterm></entry>
+      <entry>
+       One row for each column that has ever been TOASTed (compressed and/or externalized).
+       Showing the number of externalizations, compression attempts / successes, compressed and
+       uncompressed sizes etc.
+       <link linkend="monitoring-pg-stat-toast-view">
+       <structname>pg_stat_toast</structname></link> for details.
+      </entry>
+     </row>
+
      <row>
       <entry><structname>pg_stat_slru</structname><indexterm><primary>pg_stat_slru</primary></indexterm></entry>
       <entry>One row per SLRU, showing statistics of operations. See
@@ -4933,6 +4944,158 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
 
  </sect2>
 
+ <sect2 id="monitoring-pg-stat-toast-view">
+  <title><structname>pg_stat_toast</structname></title>
+
+  <indexterm>
+   <primary>pg_stat_toast</primary>
+  </indexterm>
+
+  <para>
+   The <structname>pg_stat_toast</structname> view will contain
+   one row for each column of variable size that has been TOASTed since 
+   the last statistics reset. The <xref linkend="guc-track-toast"/> parameter
+   controls whether TOAST activities are tracked or not.
+  </para>
+
+  <table id="pg-stat-toast-view" xreflabel="pg_stat_toast">
+   <title><structname>pg_stat_toast</structname> View</title>
+   <tgroup cols="1">
+    <thead>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       Column Type
+      </para>
+      <para>
+       Description
+      </para></entry>
+     </row>
+    </thead>
+
+    <tbody>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>schemaname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the schema the relation is in
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>reloid</structfield> <type>oid</type>
+      </para>
+      <para>
+       OID of the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>attnum</structfield> <type>int</type>
+      </para>
+      <para>
+       Attribute (column) number in the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>relname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>attname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the attribute (column)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>storagemethod</structfield> <type>char</type>
+      </para>
+      <para>
+       Storage method of the attribute
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>externalized</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times this attribute was externalized (pushed to TOAST relation)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressmethod</structfield> <type>char</type>
+      </para>
+      <para>
+       Current compression method of the attribute (empty means default)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressattempts</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times compression of this attribute was attempted
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compresssuccesses</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times compression of this attribute was successful
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressedsize</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total size of all compressed datums
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>originalsize</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total size of all compressed datums before compression
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>total_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Total time spent TOASTing this attribute, in microseconds.
+      </para></entry>
+     </row>
+
+    </tbody>
+   </tgroup>
+  </table>
+
+ </sect2>
+
  <sect2 id="monitoring-pg-stat-slru-view">
   <title><structname>pg_stat_slru</structname></title>
 
diff --git a/doc/src/sgml/storage.sgml b/doc/src/sgml/storage.sgml
index 7136bbe7a3..2a47922573 100644
--- a/doc/src/sgml/storage.sgml
+++ b/doc/src/sgml/storage.sgml
@@ -517,6 +517,15 @@ pages). There was no run time difference compared to an un-<acronym>TOAST</acron
 comparison table, in which all the HTML pages were cut down to 7 kB to fit.
 </para>
 
+<para>
+When you enable <xref linkend="guc-track-toast"/>, the system view
+<link linkend="monitoring-pg-stat-toast-view"><structname>pg_stat_toast</structname>
+</link> provides details on the number and effect of compression attempts,
+number of externalizations and some more useful information that enables you
+to decide if a different storage method and/or compression method would suite a
+column better.
+</para>
+
 </sect2>
 
 <sect2 id="storage-toast-inmemory">
@@ -1068,7 +1077,8 @@ data. Empty in ordinary tables.</entry>
   <type>struct varlena</type>, which includes the total length of the stored
   value and some flag bits.  Depending on the flags, the data can be either
   inline or in a <acronym>TOAST</acronym> table;
-  it might be compressed, too (see <xref linkend="storage-toast"/>).
+  it might be compressed, too (see <xref linkend="storage-toast"/> and 
+  <xref linkend="monitoring-pg-stat-toast-view"/>).
 
  </para>
  </sect2>
diff --git a/src/backend/access/table/toast_helper.c b/src/backend/access/table/toast_helper.c
index 0cc5a30f9b..43154f2be0 100644
--- a/src/backend/access/table/toast_helper.c
+++ b/src/backend/access/table/toast_helper.c
@@ -19,7 +19,9 @@
 #include "access/toast_helper.h"
 #include "access/toast_internals.h"
 #include "catalog/pg_type_d.h"
+#include "pgstat.h"
 
+extern PGDLLIMPORT bool pgstat_track_toast;
 
 /*
  * Prepare to TOAST a tuple.
@@ -229,7 +231,12 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 	Datum	   *value = &ttc->ttc_values[attribute];
 	Datum		new_value;
 	ToastAttrInfo *attr = &ttc->ttc_attr[attribute];
+	instr_time	start_time;
 
+	if (pgstat_track_toast)
+	{
+		INSTR_TIME_SET_CURRENT(start_time);
+	}
 	new_value = toast_compress_datum(*value, attr->tai_compression);
 
 	if (DatumGetPointer(new_value) != NULL)
@@ -239,6 +246,15 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 			pfree(DatumGetPointer(*value));
 		*value = new_value;
 		attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
+		if (pgstat_track_toast)
+		{
+			pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							attr->tai_size,
+							VARSIZE(DatumGetPointer(*value)),
+							start_time);
+		}
 		attr->tai_size = VARSIZE(DatumGetPointer(*value));
 		ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
 	}
@@ -246,6 +262,15 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 	{
 		/* incompressible, ignore on subsequent compression passes */
 		attr->tai_colflags |= TOASTCOL_INCOMPRESSIBLE;
+		if (pgstat_track_toast)
+		{
+			pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							0,
+							0,
+							start_time);
+		}
 	}
 }
 
@@ -258,6 +283,12 @@ toast_tuple_externalize(ToastTupleContext *ttc, int attribute, int options)
 	Datum	   *value = &ttc->ttc_values[attribute];
 	Datum		old_value = *value;
 	ToastAttrInfo *attr = &ttc->ttc_attr[attribute];
+	instr_time	start_time;
+
+	if (pgstat_track_toast)
+	{
+		INSTR_TIME_SET_CURRENT(start_time);
+	}
 
 	attr->tai_colflags |= TOASTCOL_IGNORE;
 	*value = toast_save_datum(ttc->ttc_rel, old_value, attr->tai_oldexternal,
@@ -266,6 +297,15 @@ toast_tuple_externalize(ToastTupleContext *ttc, int attribute, int options)
 		pfree(DatumGetPointer(old_value));
 	attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
 	ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
+	if (pgstat_track_toast)
+	{
+		pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							true,
+							false,
+							0,
+							0,
+							start_time);
+}
 }
 
 /*
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 40b7bca5a9..c78ab0947d 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -1041,6 +1041,26 @@ CREATE VIEW pg_stat_user_functions AS
     WHERE P.prolang != 12  -- fast check to eliminate built-in functions
           AND pg_stat_get_function_calls(P.oid) IS NOT NULL;
 
+
+CREATE OR REPLACE VIEW pg_stat_toast AS
+ SELECT
+    n.nspname AS schemaname,
+    a.attrelid AS reloid,
+    a.attnum AS attnum,
+    c.relname AS relname,
+    a.attname AS attname,
+    attstorage AS storagemethod,
+    pg_stat_get_toast_externalizations(a.attrelid,a.attnum) AS externalized,
+    attcompression AS compressmethod,
+    pg_stat_get_toast_compressions(a.attrelid,a.attnum) AS compressattempts,
+    pg_stat_get_toast_compressionsuccesses(a.attrelid,a.attnum) AS compresssuccesses,
+    pg_stat_get_toast_compressedsizesum(a.attrelid,a.attnum) AS compressedsize,
+    pg_stat_get_toast_originalsizesum(a.attrelid,a.attnum) AS originalsize,
+    pg_stat_get_toast_total_time(a.attrelid,a.attnum) AS total_time
+   FROM pg_attribute a
+   JOIN pg_class c ON c.oid = a.attrelid
+   LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
+  WHERE pg_stat_get_toast_externalizations(a.attrelid,a.attnum) IS NOT NULL;
 CREATE VIEW pg_stat_xact_user_functions AS
     SELECT
             P.oid AS funcid,
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 53ddd930e6..37290d9a9e 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -106,6 +106,7 @@
 #define PGSTAT_DB_HASH_SIZE		16
 #define PGSTAT_TAB_HASH_SIZE	512
 #define PGSTAT_FUNCTION_HASH_SIZE	512
+#define PGSTAT_TOAST_HASH_SIZE	64
 #define PGSTAT_SUBSCRIPTION_HASH_SIZE	32
 #define PGSTAT_REPLSLOT_HASH_SIZE	32
 
@@ -116,6 +117,7 @@
  */
 bool		pgstat_track_counts = false;
 int			pgstat_track_functions = TRACK_FUNC_OFF;
+bool		pgstat_track_toast = false;
 
 /* ----------
  * Built from GUC parameter
@@ -228,6 +230,19 @@ static HTAB *pgStatFunctions = NULL;
  */
 static bool have_function_stats = false;
 
+/*
+ * Backends store per-toast-column info that's waiting to be sent to the collector
+ * in this hash table (indexed by column's PgStat_BackendAttrIdentifier).
+ */
+static HTAB *pgStatToastActions = NULL;
+
+
+/*
+ * Indicates if backend has some toast stats that it hasn't yet
+ * sent to the collector.
+ */
+static bool have_toast_stats = false;
+
 /*
  * Tuple insertion/deletion counts for an open transaction can't be propagated
  * into PgStat_TableStatus counters until we know if it is going to commit
@@ -328,7 +343,7 @@ static void pgstat_reset_subscription(PgStat_StatSubEntry *subentry, TimestampTz
 static void pgstat_write_statsfiles(bool permanent, bool allDbs);
 static void pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent);
 static HTAB *pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep);
-static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 									 bool permanent);
 static void backend_read_statsfile(void);
 
@@ -340,6 +355,7 @@ static void pgstat_reset_replslot(PgStat_StatReplSlotEntry *slotstats, Timestamp
 
 static void pgstat_send_tabstat(PgStat_MsgTabstat *tsmsg, TimestampTz now);
 static void pgstat_send_funcstats(void);
+static void pgstat_send_toaststats(void);
 static void pgstat_send_slru(void);
 static HTAB *pgstat_collect_oids(Oid catalogid, AttrNumber anum_oid);
 static bool pgstat_should_report_connstat(void);
@@ -373,6 +389,7 @@ static void pgstat_recv_wal(PgStat_MsgWal *msg, int len);
 static void pgstat_recv_slru(PgStat_MsgSLRU *msg, int len);
 static void pgstat_recv_funcstat(PgStat_MsgFuncstat *msg, int len);
 static void pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len);
+static void pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len);
 static void pgstat_recv_recoveryconflict(PgStat_MsgRecoveryConflict *msg, int len);
 static void pgstat_recv_deadlock(PgStat_MsgDeadlock *msg, int len);
 static void pgstat_recv_checksum_failure(PgStat_MsgChecksumFailure *msg, int len);
@@ -891,7 +908,7 @@ pgstat_report_stat(bool disconnect)
 		pgStatXactCommit == 0 && pgStatXactRollback == 0 &&
 		pgWalUsage.wal_records == prevWalUsage.wal_records &&
 		WalStats.m_wal_write == 0 && WalStats.m_wal_sync == 0 &&
-		!have_function_stats && !disconnect)
+		!have_function_stats && !have_toast_stats && !disconnect)
 		return;
 
 	/*
@@ -983,6 +1000,9 @@ pgstat_report_stat(bool disconnect)
 	/* Now, send function statistics */
 	pgstat_send_funcstats();
 
+	/* Now, send TOAST statistics */
+	pgstat_send_toaststats();
+
 	/* Send WAL statistics */
 	pgstat_send_wal(true);
 
@@ -1116,6 +1136,63 @@ pgstat_send_funcstats(void)
 	have_function_stats = false;
 }
 
+/*
+ * Subroutine for pgstat_report_stat: populate and send a toast stat message
+ */
+static void
+pgstat_send_toaststats(void)
+{
+	static const PgStat_ToastCounts all_zeroes;
+
+	PgStat_MsgToaststat msg;
+	PgStat_BackendToastEntry *entry;
+	HASH_SEQ_STATUS tstat;
+
+	if (pgStatToastActions == NULL)
+		return;
+
+	pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_TOASTSTAT);
+	msg.m_databaseid = MyDatabaseId;
+	msg.m_nentries = 0;
+
+	hash_seq_init(&tstat, pgStatToastActions);
+	while ((entry = (PgStat_BackendToastEntry *) hash_seq_search(&tstat)) != NULL)
+	{
+		PgStat_ToastEntry *m_ent;
+
+		/* Skip it if no counts accumulated since last time */
+		if (memcmp(&entry->t_counts, &all_zeroes,
+				   sizeof(PgStat_ToastCounts)) == 0)
+			continue;
+
+		/* need to convert format of time accumulators */
+		m_ent = &msg.m_entry[msg.m_nentries];
+		m_ent->attr = entry->attr;
+		m_ent->t_numexternalized = entry->t_counts.t_numexternalized;
+		m_ent->t_numcompressed = entry->t_counts.t_numcompressed;
+		m_ent->t_numcompressionsuccess = entry->t_counts.t_numcompressionsuccess;
+		m_ent->t_size_orig = entry->t_counts.t_size_orig;
+		m_ent->t_size_compressed = entry->t_counts.t_size_compressed;
+		m_ent->t_comp_time = INSTR_TIME_GET_MICROSEC(entry->t_counts.t_comp_time);
+
+		if (++msg.m_nentries >= PGSTAT_NUM_TOASTENTRIES)
+		{
+			pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+						msg.m_nentries * sizeof(PgStat_ToastEntry));
+			msg.m_nentries = 0;
+		}
+
+		/* reset the entry's counts */
+		MemSet(&entry->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	if (msg.m_nentries > 0)
+		pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+					msg.m_nentries * sizeof(PgStat_ToastEntry));
+
+	have_toast_stats = false;
+}
+
 
 /* ----------
  * pgstat_vacuum_stat() -
@@ -2119,6 +2196,72 @@ pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu, bool finalize)
 	have_function_stats = true;
 }
 
+/*
+ * Report TOAST activity
+ * Called by toast_helper functions.
+ */
+void
+pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							instr_time start_time)
+{
+	PgStat_BackendAttrIdentifier toastattr = { relid, attr };
+	PgStat_BackendToastEntry *htabent;
+	instr_time	time_spent;
+	bool		found;
+
+	if (pgStatSock == PGINVALID_SOCKET || !pgstat_track_toast)
+		return;
+
+	INSTR_TIME_SET_CURRENT(time_spent);
+	INSTR_TIME_SUBTRACT(time_spent, start_time);
+
+	if (!pgStatToastActions)
+	{
+		/* First time through - initialize toast stat table */
+		HASHCTL		hash_ctl;
+
+		hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+		hash_ctl.entrysize = sizeof(PgStat_BackendToastEntry);
+		pgStatToastActions = hash_create("TOAST stat entries",
+									  PGSTAT_TOAST_HASH_SIZE,
+									  &hash_ctl,
+									  HASH_ELEM | HASH_BLOBS);
+	}
+
+	/* Get the stats entry for this TOAST attribute, create if necessary */
+	htabent = hash_search(pgStatToastActions, &toastattr,
+						  HASH_ENTER, &found);
+	if (!found)
+	{
+		MemSet(&htabent->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	/* update counters */
+	if (externalized)
+	{
+		htabent->t_counts.t_numexternalized++;
+	}
+	if (compressed)
+	{
+		htabent->t_counts.t_numcompressed++;
+		htabent->t_counts.t_size_orig+=old_size;
+		if (new_size)
+		{
+			htabent->t_counts.t_numcompressionsuccess++;
+			htabent->t_counts.t_size_compressed+=new_size;
+		}
+	}
+	/* record time spent */
+	INSTR_TIME_ADD(htabent->t_counts.t_comp_time, time_spent);
+
+	/* indicate that we have something to send */
+	have_toast_stats = true;
+}
+
 
 /* ----------
  * pgstat_initstats() -
@@ -2966,6 +3109,35 @@ pgstat_fetch_stat_funcentry(Oid func_id)
 	return funcentry;
 }
 
+/* ----------
+ * pgstat_fetch_stat_toastentry() -
+ *
+ *	Support function for the SQL-callable pgstat* functions. Returns
+ *	the collected statistics for one TOAST attribute or NULL.
+ * ----------
+ */
+PgStat_StatToastEntry *
+pgstat_fetch_stat_toastentry(Oid rel_id, int attr)
+{
+	PgStat_StatDBEntry *dbentry;
+	PgStat_BackendAttrIdentifier toast_id = { rel_id, attr };
+	PgStat_StatToastEntry *toastentry = NULL;
+
+	/* load the stats file if needed */
+	backend_read_statsfile();
+
+	/* Lookup our database, then find the requested TOAST activity stats.  */
+	dbentry = pgstat_fetch_stat_dbentry(MyDatabaseId);
+	if (dbentry != NULL && dbentry->toastactivity != NULL)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &toast_id,
+														 HASH_FIND, NULL);
+	}
+
+	return toastentry;
+}
+
 /*
  * ---------
  * pgstat_fetch_stat_archiver() -
@@ -3649,6 +3821,10 @@ PgstatCollectorMain(int argc, char *argv[])
 					pgstat_recv_funcpurge(&msg.msg_funcpurge, len);
 					break;
 
+				case PGSTAT_MTYPE_TOASTSTAT:
+					pgstat_recv_toaststat(&msg.msg_toaststat, len);
+					break;
+
 				case PGSTAT_MTYPE_RECOVERYCONFLICT:
 					pgstat_recv_recoveryconflict(&msg.msg_recoveryconflict,
 												 len);
@@ -3785,6 +3961,13 @@ reset_dbentry_counters(PgStat_StatDBEntry *dbentry)
 									 PGSTAT_FUNCTION_HASH_SIZE,
 									 &hash_ctl,
 									 HASH_ELEM | HASH_BLOBS);
+
+	hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+	hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+	dbentry->toastactivity = hash_create("Per-database TOAST",
+									 PGSTAT_TOAST_HASH_SIZE,
+									 &hash_ctl,
+									 HASH_ELEM | HASH_BLOBS);
 }
 
 /*
@@ -3950,7 +4133,7 @@ pgstat_write_statsfiles(bool permanent, bool allDbs)
 	while ((dbentry = (PgStat_StatDBEntry *) hash_seq_search(&hstat)) != NULL)
 	{
 		/*
-		 * Write out the table and function stats for this DB into the
+		 * Write out the table, function and TOAST stats for this DB into the
 		 * appropriate per-DB stat file, if required.
 		 */
 		if (allDbs || pgstat_db_requested(dbentry->databaseid))
@@ -4081,8 +4264,10 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 {
 	HASH_SEQ_STATUS tstat;
 	HASH_SEQ_STATUS fstat;
+	HASH_SEQ_STATUS ostat;
 	PgStat_StatTabEntry *tabentry;
 	PgStat_StatFuncEntry *funcentry;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpout;
 	int32		format_id;
 	Oid			dbid = dbentry->databaseid;
@@ -4137,6 +4322,17 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 		(void) rc;				/* we'll check for error with ferror */
 	}
 
+	/*
+	 * Walk through the database's TOAST stats table.
+	 */
+	hash_seq_init(&ostat, dbentry->toastactivity);
+	while ((toastentry = (PgStat_StatToastEntry *) hash_seq_search(&ostat)) != NULL)
+	{
+		fputc('O', fpout);
+		rc = fwrite(toastentry, sizeof(PgStat_StatToastEntry), 1, fpout);
+		(void) rc;				/* we'll check for error with ferror */
+	}
+
 	/*
 	 * No more output to be done. Close the temp file and replace the old
 	 * pgstat.stat with it.  The ferror() check replaces testing for error
@@ -4375,6 +4571,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 				memcpy(dbentry, &dbbuf, sizeof(PgStat_StatDBEntry));
 				dbentry->tables = NULL;
 				dbentry->functions = NULL;
+				dbentry->toastactivity = NULL;
 
 				/*
 				 * In the collector, disregard the timestamp we read from the
@@ -4412,6 +4609,14 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 												 &hash_ctl,
 												 HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
 
+				hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+				hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+				hash_ctl.hcxt = pgStatLocalContext;
+				dbentry->toastactivity = hash_create("Per-database toast information",
+												 PGSTAT_TOAST_HASH_SIZE,
+												 &hash_ctl,
+												 HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
+
 				/*
 				 * If requested, read the data from the database-specific
 				 * file.  Otherwise we just leave the hashtables empty.
@@ -4420,6 +4625,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 					pgstat_read_db_statsfile(dbentry->databaseid,
 											 dbentry->tables,
 											 dbentry->functions,
+											 dbentry->toastactivity,
 											 permanent);
 
 				break;
@@ -4542,13 +4748,15 @@ done:
  * ----------
  */
 static void
-pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 						 bool permanent)
 {
 	PgStat_StatTabEntry *tabentry;
 	PgStat_StatTabEntry tabbuf;
 	PgStat_StatFuncEntry funcbuf;
 	PgStat_StatFuncEntry *funcentry;
+	PgStat_StatToastEntry toastbuf;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpin;
 	int32		format_id;
 	bool		found;
@@ -4662,6 +4870,32 @@ pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
 				memcpy(funcentry, &funcbuf, sizeof(funcbuf));
 				break;
 
+
+				/*
+				 * 'O'	A PgStat_StatToastEntry follows (tOast)
+				 */
+			case 'O':
+				if (fread(&toastbuf, 1, sizeof(PgStat_StatToastEntry),
+						  fpin) != sizeof(PgStat_StatToastEntry))
+				{
+					ereport(pgStatRunningInCollector ? LOG : WARNING,
+							(errmsg("corrupted statistics file \"%s\"",
+									statfile)));
+					goto done;
+				}
+
+				/*
+				 * Skip if TOAST data not wanted.
+				 */
+				if (toasthash == NULL)
+					break;
+
+				toastentry = (PgStat_StatToastEntry *) hash_search(toasthash,
+																 (void *) &toastbuf.t_id,
+																 HASH_ENTER, &found);
+				memcpy(toastentry, &toastbuf, sizeof(toastbuf));
+				break;
+
 				/*
 				 * 'E'	The EOF marker of a complete stats file.
 				 */
@@ -5353,6 +5587,8 @@ pgstat_recv_dropdb(PgStat_MsgDropdb *msg, int len)
 			hash_destroy(dbentry->tables);
 		if (dbentry->functions != NULL)
 			hash_destroy(dbentry->functions);
+		if (dbentry->toastactivity != NULL)
+			hash_destroy(dbentry->toastactivity);
 
 		if (hash_search(pgStatDBHash,
 						(void *) &dbid,
@@ -5390,9 +5626,11 @@ pgstat_recv_resetcounter(PgStat_MsgResetcounter *msg, int len)
 		hash_destroy(dbentry->tables);
 	if (dbentry->functions != NULL)
 		hash_destroy(dbentry->functions);
-
+	if (dbentry->toastactivity != NULL)
+		hash_destroy(dbentry->toastactivity);
 	dbentry->tables = NULL;
 	dbentry->functions = NULL;
+	dbentry->toastactivity = NULL;
 
 	/*
 	 * Reset database-level stats, too.  This creates empty hash tables for
@@ -6052,6 +6290,60 @@ pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len)
 	}
 }
 
+/* ----------
+ * pgstat_recv_toaststat() -
+ *
+ *	Count what the backend has done.
+ * ----------
+ */
+static void
+pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len)
+{
+	PgStat_ToastEntry *toastmsg = &(msg->m_entry[0]);
+	PgStat_StatDBEntry *dbentry;
+	PgStat_StatToastEntry *toastentry;
+	int			i;
+	bool		found;
+
+	dbentry = pgstat_get_db_entry(msg->m_databaseid, true);
+
+	/*
+	 * Process all TOAST entries in the message.
+	 */
+	for (i = 0; i < msg->m_nentries; i++, toastmsg++)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &(toastmsg->attr),
+														 HASH_ENTER, &found);
+
+		if (!found)
+		{
+			/*
+			 * If it's a new entry, initialize counters to the values
+			 * we just got.
+			 */
+			toastentry->t_numexternalized = toastmsg->t_numexternalized;
+			toastentry->t_numcompressed = toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess = toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_orig = toastmsg->t_size_orig;
+			toastentry->t_size_compressed = toastmsg->t_size_compressed;
+			toastentry->t_comp_time = toastmsg->t_comp_time;
+		}
+		else
+		{
+			/*
+			 * Otherwise add the values to the existing entry.
+			 */
+			toastentry->t_numexternalized += toastmsg->t_numexternalized;
+			toastentry->t_numcompressed += toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess += toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_orig += toastmsg->t_size_orig;
+			toastentry->t_size_compressed += toastmsg->t_size_compressed;
+			toastentry->t_comp_time += toastmsg->t_comp_time;
+		}
+	}
+}
+
 /* ----------
  * pgstat_recv_subscription_drop() -
  *
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index eff45b16f2..203c279795 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -410,6 +410,78 @@ pg_stat_get_function_self_time(PG_FUNCTION_ARGS)
 	PG_RETURN_FLOAT8(((double) funcentry->f_self_time) / 1000.0);
 }
 
+Datum
+pg_stat_get_toast_externalizations(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numexternalized);
+}
+
+Datum
+pg_stat_get_toast_compressions(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressed);
+}
+
+Datum
+pg_stat_get_toast_compressionsuccesses(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressionsuccess);
+}
+
+Datum
+pg_stat_get_toast_originalsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_orig);
+}
+
+Datum
+pg_stat_get_toast_compressedsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_compressed);
+}
+
+Datum
+pg_stat_get_toast_total_time(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_comp_time);
+}
+
 Datum
 pg_stat_get_backend_idset(PG_FUNCTION_ARGS)
 {
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 6d11f9c71b..7728f8165d 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -1543,6 +1543,15 @@ static struct config_bool ConfigureNamesBool[] =
 		true,
 		NULL, NULL, NULL
 	},
+	{
+		{"track_toast", PGC_SUSET, STATS_COLLECTOR,
+			gettext_noop("Collects statistics on TOAST activity."),
+			NULL
+		},
+		&pgstat_track_toast,
+		false,
+		NULL, NULL, NULL
+	},
 	{
 		{"track_io_timing", PGC_SUSET, STATS_COLLECTOR,
 			gettext_noop("Collects timing statistics for database I/O activity."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 4a094bb38b..64d559c804 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -611,6 +611,7 @@
 #track_io_timing = off
 #track_wal_io_timing = off
 #track_functions = none			# none, pl, all
+#track_toast = off
 #stats_temp_directory = 'pg_stat_tmp'
 
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index d8e8715ed1..5ce9667b0b 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5673,6 +5673,31 @@
   proparallel => 'r', prorettype => 'float8', proargtypes => 'oid',
   prosrc => 'pg_stat_get_function_self_time' },
 
+{ oid => '9700', descr => 'statistics: number of TOAST externalizations',
+  proname => 'pg_stat_get_toast_externalizations', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_externalizations' },
+{ oid => '9701', descr => 'statistics: number of TOAST compressions',
+  proname => 'pg_stat_get_toast_compressions', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressions' },
+  { oid => '9702', descr => 'statistics: number of successful TOAST compressions',
+  proname => 'pg_stat_get_toast_compressionsuccesses', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressionsuccesses' },
+{ oid => '9703', descr => 'statistics: total original size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_originalsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_originalsizesum' },
+{ oid => '9704', descr => 'statistics: total compressed size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_compressedsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressedsizesum' },
+{ oid => '9705', descr => 'statistics: total time spend TOASTing data',
+  proname => 'pg_stat_get_toast_total_time', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_total_time' },
+
 { oid => '3037',
   descr => 'statistics: number of scans done for table/index in current transaction',
   proname => 'pg_stat_get_xact_numscans', provolatile => 'v',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index be2f7e2bcc..e17ed5e09b 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -87,6 +87,7 @@ typedef enum StatMsgType
 	PGSTAT_MTYPE_DISCONNECT,
 	PGSTAT_MTYPE_SUBSCRIPTIONDROP,
 	PGSTAT_MTYPE_SUBSCRIPTIONERROR,
+	PGSTAT_MTYPE_TOASTSTAT,
 } StatMsgType;
 
 /* ----------
@@ -720,6 +721,80 @@ typedef struct PgStat_MsgDisconnect
 	SessionEndType m_cause;
 } PgStat_MsgDisconnect;
 
+/* ----------
+ * PgStat_BackendAttrIdentifier	Identifier for a single attribute/column (OID + attr)
+ * Used as a hashable identifier for (e.g.) TOAST columns
+ * ----------
+ */
+typedef struct PgStat_BackendAttrIdentifier
+{
+	Oid			relid;
+	int			attr;
+} PgStat_BackendAttrIdentifier;
+
+/* ----------
+ * PgStat_ToastCounts	The actual per-TOAST counts kept by a backend
+ *
+ * This struct should contain only actual event counters, because we memcmp
+ * it against zeroes to detect whether there are any counts to transmit.
+ *
+ * Note that the time counters are in instr_time format here.  We convert to
+ * microseconds in PgStat_Counter format when transmitting to the collector.
+ * ----------
+ */
+typedef struct PgStat_ToastCounts
+{
+	PgStat_Counter	t_numexternalized;
+	PgStat_Counter	t_numcompressed;
+	PgStat_Counter	t_numcompressionsuccess;
+	uint64		t_size_orig;
+	uint64		t_size_compressed;
+	instr_time	t_comp_time;
+} PgStat_ToastCounts;
+
+/* ----------
+ * PgStat_BackendToastEntry	Entry in backend's per-toast-attr hash table
+ * ----------
+ */
+typedef struct PgStat_BackendToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_ToastCounts 		t_counts;
+} PgStat_BackendToastEntry;
+
+/* ----------
+ * PgStat_ToastEntry			Per-TOAST-column info in a MsgToaststat
+ * ----------
+ */
+typedef struct PgStat_ToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_Counter 			t_numexternalized;
+	PgStat_Counter 			t_numcompressed;
+	PgStat_Counter 			t_numcompressionsuccess;
+	uint64		   		t_size_orig;
+	uint64		   		t_size_compressed;
+	PgStat_Counter			t_comp_time;	/* time in microseconds */
+} PgStat_ToastEntry;
+
+/* ----------
+ * PgStat_MsgToaststat			Sent by the backend to report function
+ *								usage statistics.
+ * ----------
+ */
+#define PGSTAT_NUM_TOASTENTRIES	\
+	((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - sizeof(int))  \
+	 / sizeof(PgStat_ToastEntry))
+
+typedef struct PgStat_MsgToaststat
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+	int			m_nentries;
+	PgStat_ToastEntry m_entry[PGSTAT_NUM_TOASTENTRIES];
+} PgStat_MsgToaststat;
+
+
 /* ----------
  * PgStat_Msg					Union over all possible messages.
  * ----------
@@ -748,6 +823,7 @@ typedef union PgStat_Msg
 	PgStat_MsgSLRU msg_slru;
 	PgStat_MsgFuncstat msg_funcstat;
 	PgStat_MsgFuncpurge msg_funcpurge;
+	PgStat_MsgToaststat msg_toaststat;
 	PgStat_MsgRecoveryConflict msg_recoveryconflict;
 	PgStat_MsgDeadlock msg_deadlock;
 	PgStat_MsgTempFile msg_tempfile;
@@ -768,7 +844,7 @@ typedef union PgStat_Msg
  * ------------------------------------------------------------
  */
 
-#define PGSTAT_FILE_FORMAT_ID	0x01A5BCA6
+#define PGSTAT_FILE_FORMAT_ID	0x01A5BCA7
 
 /* ----------
  * PgStat_StatDBEntry			The collector's data per database
@@ -816,6 +892,7 @@ typedef struct PgStat_StatDBEntry
 	 */
 	HTAB	   *tables;
 	HTAB	   *functions;
+	HTAB	   *toastactivity;
 } PgStat_StatDBEntry;
 
 
@@ -984,6 +1061,22 @@ typedef struct PgStat_StatSubEntry
 	TimestampTz stat_reset_timestamp;
 } PgStat_StatSubEntry;
 
+/* ----------
+ * PgStat_StatToastEntry			The collector's data per TOAST attribute
+ * ----------
+ */
+typedef struct PgStat_StatToastEntry
+{
+	PgStat_BackendAttrIdentifier t_id;
+	PgStat_Counter t_numexternalized;
+	PgStat_Counter t_numcompressed;
+	PgStat_Counter t_numcompressionsuccess;
+	uint64		   t_size_orig;
+	uint64		   t_size_compressed;
+	PgStat_Counter t_comp_time;	/* time in microseconds */
+} PgStat_StatToastEntry;
+
+
 /*
  * Working state needed to accumulate per-function-call timing statistics.
  */
@@ -1007,6 +1100,7 @@ typedef struct PgStat_FunctionCallUsage
  */
 extern PGDLLIMPORT bool pgstat_track_counts;
 extern PGDLLIMPORT int pgstat_track_functions;
+extern PGDLLIMPORT bool pgstat_track_toast;
 extern char *pgstat_stat_directory;
 extern char *pgstat_stat_tmpname;
 extern char *pgstat_stat_filename;
@@ -1156,12 +1250,22 @@ extern void pgstat_count_heap_delete(Relation rel);
 extern void pgstat_count_truncate(Relation rel);
 extern void pgstat_update_heap_dead_tuples(Relation rel, int delta);
 
+extern void pgstat_count_toast_insert(Relation rel, PgStat_Counter n);
+
 struct FunctionCallInfoBaseData;
 extern void pgstat_init_function_usage(struct FunctionCallInfoBaseData *fcinfo,
 									   PgStat_FunctionCallUsage *fcu);
 extern void pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu,
 									  bool finalize);
 
+extern void
+pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							instr_time start_time);
+
 extern void AtEOXact_PgStat(bool isCommit, bool parallel);
 extern void AtEOSubXact_PgStat(bool isCommit, int nestDepth);
 
@@ -1186,6 +1290,7 @@ extern void pgstat_send_wal(bool force);
 extern PgStat_StatDBEntry *pgstat_fetch_stat_dbentry(Oid dbid);
 extern PgStat_StatTabEntry *pgstat_fetch_stat_tabentry(Oid relid);
 extern PgStat_StatFuncEntry *pgstat_fetch_stat_funcentry(Oid funcid);
+extern PgStat_StatToastEntry *pgstat_fetch_stat_toastentry(Oid rel_id, int attr);
 extern PgStat_StatSubEntry *pgstat_fetch_stat_subscription(Oid subid);
 extern PgStat_ArchiverStats *pgstat_fetch_stat_archiver(void);
 extern PgStat_BgWriterStats *pgstat_fetch_stat_bgwriter(void);
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index ac468568a1..f40d7bb208 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -2114,6 +2114,23 @@ pg_stat_sys_tables| SELECT pg_stat_all_tables.relid,
     pg_stat_all_tables.autoanalyze_count
    FROM pg_stat_all_tables
   WHERE ((pg_stat_all_tables.schemaname = ANY (ARRAY['pg_catalog'::name, 'information_schema'::name])) OR (pg_stat_all_tables.schemaname ~ '^pg_toast'::text));
+pg_stat_toast| SELECT n.nspname AS schemaname,
+    a.attrelid AS reloid,
+    a.attnum,
+    c.relname,
+    a.attname,
+    a.attstorage AS storagemethod,
+    pg_stat_get_toast_externalizations(a.attrelid, (a.attnum)::integer) AS externalized,
+    a.attcompression AS compressmethod,
+    pg_stat_get_toast_compressions(a.attrelid, (a.attnum)::integer) AS compressattempts,
+    pg_stat_get_toast_compressionsuccesses(a.attrelid, (a.attnum)::integer) AS compresssuccesses,
+    pg_stat_get_toast_compressedsizesum(a.attrelid, (a.attnum)::integer) AS compressedsize,
+    pg_stat_get_toast_originalsizesum(a.attrelid, (a.attnum)::integer) AS originalsize,
+    pg_stat_get_toast_total_time(a.attrelid, (a.attnum)::integer) AS total_time
+   FROM ((pg_attribute a
+     JOIN pg_class c ON ((c.oid = a.attrelid)))
+     LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace)))
+  WHERE (pg_stat_get_toast_externalizations(a.attrelid, (a.attnum)::integer) IS NOT NULL);
 pg_stat_user_functions| SELECT p.oid AS funcid,
     n.nspname AS schemaname,
     p.proname AS funcname,
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index b7416c8f8f..da8631f7b1 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -11,6 +11,32 @@ SHOW track_counts;  -- must be on
  on
 (1 row)
 
+-- prepare and fill the pg_stat_toast table now:
+SHOW track_toast;
+ track_toast 
+-------------
+ off
+(1 row)
+
+SET track_toast TO on;
+SHOW track_toast;
+ track_toast 
+-------------
+ on
+(1 row)
+
+TABLE pg_stat_toast; -- view exists
+ schemaname | reloid | attnum | relname | attname | storagemethod | externalized | compressmethod | compressattempts | compresssuccesses | compressedsize | originalsize | total_time 
+------------+--------+--------+---------+---------+---------------+--------------+----------------+------------------+-------------------+----------------+--------------+------------
+(0 rows)
+
+CREATE TABLE toast_test (cola TEXT, colb TEXT, colc TEXT , cold TEXT);
+ALTER TABLE toast_test ALTER colb SET STORAGE EXTERNAL;
+ALTER TABLE toast_test ALTER colc SET STORAGE MAIN;
+ALTER TABLE toast_test ALTER cold SET STORAGE PLAIN;
+INSERT INTO toast_test VALUES (repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100) );
+-- make sure we don't interfere with the other tests:
+SET track_toast TO off;
 -- ensure that both seqscan and indexscan plans are allowed
 SET enable_seqscan TO on;
 SET enable_indexscan TO on;
@@ -255,4 +281,40 @@ SELECT pg_stat_get_tuples_hot_updated('brin_hot'::regclass::oid);
 
 DROP TABLE brin_hot;
 DROP FUNCTION wait_for_hot_stats();
+-- now check that the track_toast stuff worked:
+SELECT attname
+	,storagemethod
+	,externalized
+	,compressmethod
+	,compressattempts
+	,compresssuccesses
+	,compressedsize < originalsize AS compression_works
+	, total_time > 0 AS takes_time
+FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY attname;
+ attname | storagemethod | externalized | compressmethod | compressattempts | compresssuccesses | compression_works | takes_time 
+---------+---------------+--------------+----------------+------------------+-------------------+-------------------+------------
+ cola    | x             |            1 |                |                1 |                 1 | t                 | t
+ colb    | e             |            1 |                |                0 |                 0 | f                 | t
+ colc    | m             |            0 |                |                1 |                 1 | t                 | t
+(3 rows)
+
+SELECT compressattempts=0 AS external_doesnt_compress FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'e';
+ external_doesnt_compress 
+--------------------------
+ t
+(1 row)
+
+SELECT externalized=0 AS main_doesnt_externalize FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'm';
+ main_doesnt_externalize 
+-------------------------
+ t
+(1 row)
+
+DROP TABLE toast_test;
+SELECT count(*) FROM pg_stat_toast WHERE relname = 'toast_test';
+ count 
+-------
+     0
+(1 row)
+
 -- End of Stats Test
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index dbc2dd28b6..81890d1238 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -8,6 +8,20 @@
 -- conditio sine qua non
 SHOW track_counts;  -- must be on
 
+-- prepare and fill the pg_stat_toast table now:
+SHOW track_toast;
+SET track_toast TO on;
+SHOW track_toast;
+TABLE pg_stat_toast; -- view exists
+
+CREATE TABLE toast_test (cola TEXT, colb TEXT, colc TEXT , cold TEXT);
+ALTER TABLE toast_test ALTER colb SET STORAGE EXTERNAL;
+ALTER TABLE toast_test ALTER colc SET STORAGE MAIN;
+ALTER TABLE toast_test ALTER cold SET STORAGE PLAIN;
+INSERT INTO toast_test VALUES (repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100) );
+-- make sure we don't interfere with the other tests:
+SET track_toast TO off;
+
 -- ensure that both seqscan and indexscan plans are allowed
 SET enable_seqscan TO on;
 SET enable_indexscan TO on;
@@ -228,5 +242,19 @@ SELECT pg_stat_get_tuples_hot_updated('brin_hot'::regclass::oid);
 DROP TABLE brin_hot;
 DROP FUNCTION wait_for_hot_stats();
 
+-- now check that the track_toast stuff worked:
+SELECT attname
+	,storagemethod
+	,externalized
+	,compressmethod
+	,compressattempts
+	,compresssuccesses
+	,compressedsize < originalsize AS compression_works
+	, total_time > 0 AS takes_time
+FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY attname;
+SELECT compressattempts=0 AS external_doesnt_compress FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'e';
+SELECT externalized=0 AS main_doesnt_externalize FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'm';
+DROP TABLE toast_test;
+SELECT count(*) FROM pg_stat_toast WHERE relname = 'toast_test';
 
 -- End of Stats Test

 doc/src/sgml/config.sgml                      |  26 ++++
 doc/src/sgml/monitoring.sgml                  | 163 ++++++++++++++++++++++++++
 doc/src/sgml/storage.sgml                     |  12 +-
 src/backend/access/table/toast_helper.c       |  40 +++++++
 src/backend/catalog/system_views.sql          |  20 ++++
 src/backend/postmaster/pgstat.c               | 161 ++++++++++++++++++++++++-
 src/backend/utils/activity/Makefile           |   1 +
 src/backend/utils/activity/pgstat_toast.c     | 157 +++++++++++++++++++++++++
 src/backend/utils/adt/pgstatfuncs.c           |  72 ++++++++++++
 src/backend/utils/misc/guc.c                  |   9 ++
 src/backend/utils/misc/postgresql.conf.sample |   1 +
 src/include/catalog/pg_proc.dat               |  25 ++++
 src/include/pgstat.h                          | 110 ++++++++++++++++-
 src/include/utils/pgstat_internal.h           |   1 +
 src/test/regress/expected/rules.out           |  17 +++
 src/test/regress/expected/stats.out           |  62 ++++++++++
 src/test/regress/sql/stats.sql                |  28 +++++
 17 files changed, 897 insertions(+), 8 deletions(-)

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 7a48973b3c..64b4219ded 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -7892,6 +7892,32 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv;
       </listitem>
      </varlistentry>
 
+     <varlistentry id="guc-track-toast" xreflabel="track_toast">
+      <term><varname>track_toast</varname> (<type>boolean</type>)
+      <indexterm>
+       <primary><varname>track_toast</varname> configuration parameter</primary>
+      </indexterm>
+      </term>
+      <listitem>
+       <para>
+        Enables tracking of <link linkend="storage-toast">TOAST</link> activities.
+        Compressions and externalizations are tracked.
+        The default is <literal>off</literal>.
+        Only superusers can change this setting.
+       </para>
+
+       <note>
+        <para>
+        Be aware that this feature, depending on the amount of TOASTable columns in
+        your databases, may significantly increase the size of the statistics files
+        and the workload of the statistics collector. It is recommended to only
+        temporarily activate this to assess the right compression and storage method
+        for a column.
+        </para>
+       </note>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="guc-stats-temp-directory" xreflabel="stats_temp_directory">
       <term><varname>stats_temp_directory</varname> (<type>string</type>)
       <indexterm>
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 35b2923c5e..7bbacd67fb 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -610,6 +610,17 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
       yet included in <structname>pg_stat_user_functions</structname>).</entry>
      </row>
 
+     <row>
+      <entry><structname>pg_stat_toast</structname><indexterm><primary>pg_stat_toast</primary></indexterm></entry>
+      <entry>
+       One row for each column that has ever been TOASTed (compressed and/or externalized).
+       Showing the number of externalizations, compression attempts / successes, compressed and
+       uncompressed sizes etc.
+       <link linkend="monitoring-pg-stat-toast-view">
+       <structname>pg_stat_toast</structname></link> for details.
+      </entry>
+     </row>
+
      <row>
       <entry><structname>pg_stat_slru</structname><indexterm><primary>pg_stat_slru</primary></indexterm></entry>
       <entry>One row per SLRU, showing statistics of operations. See
@@ -4942,6 +4953,158 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
 
  </sect2>
 
+ <sect2 id="monitoring-pg-stat-toast-view">
+  <title><structname>pg_stat_toast</structname></title>
+
+  <indexterm>
+   <primary>pg_stat_toast</primary>
+  </indexterm>
+
+  <para>
+   The <structname>pg_stat_toast</structname> view will contain
+   one row for each column of variable size that has been TOASTed since 
+   the last statistics reset. The <xref linkend="guc-track-toast"/> parameter
+   controls whether TOAST activities are tracked or not.
+  </para>
+
+  <table id="pg-stat-toast-view" xreflabel="pg_stat_toast">
+   <title><structname>pg_stat_toast</structname> View</title>
+   <tgroup cols="1">
+    <thead>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       Column Type
+      </para>
+      <para>
+       Description
+      </para></entry>
+     </row>
+    </thead>
+
+    <tbody>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>schemaname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the schema the relation is in
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>reloid</structfield> <type>oid</type>
+      </para>
+      <para>
+       OID of the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>attnum</structfield> <type>int</type>
+      </para>
+      <para>
+       Attribute (column) number in the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>relname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>attname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the attribute (column)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>storagemethod</structfield> <type>char</type>
+      </para>
+      <para>
+       Storage method of the attribute
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>externalized</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times this attribute was externalized (pushed to TOAST relation)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressmethod</structfield> <type>char</type>
+      </para>
+      <para>
+       Current compression method of the attribute (empty means default)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressattempts</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times compression of this attribute was attempted
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compresssuccesses</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times compression of this attribute was successful
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressedsize</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total size of all compressed datums
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>originalsize</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total size of all compressed datums before compression
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>total_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Total time spent TOASTing this attribute, in microseconds.
+      </para></entry>
+     </row>
+
+    </tbody>
+   </tgroup>
+  </table>
+
+ </sect2>
+
  <sect2 id="monitoring-pg-stat-slru-view">
   <title><structname>pg_stat_slru</structname></title>
 
diff --git a/doc/src/sgml/storage.sgml b/doc/src/sgml/storage.sgml
index f4b9f66589..d0e165d5f1 100644
--- a/doc/src/sgml/storage.sgml
+++ b/doc/src/sgml/storage.sgml
@@ -517,6 +517,15 @@ pages). There was no run time difference compared to an un-<acronym>TOAST</acron
 comparison table, in which all the HTML pages were cut down to 7 kB to fit.
 </para>
 
+<para>
+When you enable <xref linkend="guc-track-toast"/>, the system view
+<link linkend="monitoring-pg-stat-toast-view"><structname>pg_stat_toast</structname>
+</link> provides details on the number and effect of compression attempts,
+number of externalizations and some more useful information that enables you
+to decide if a different storage method and/or compression method would suite a
+column better.
+</para>
+
 </sect2>
 
 <sect2 id="storage-toast-inmemory">
@@ -1069,7 +1078,8 @@ data. Empty in ordinary tables.</entry>
   <type>struct varlena</type>, which includes the total length of the stored
   value and some flag bits.  Depending on the flags, the data can be either
   inline or in a <acronym>TOAST</acronym> table;
-  it might be compressed, too (see <xref linkend="storage-toast"/>).
+  it might be compressed, too (see <xref linkend="storage-toast"/> and 
+  <xref linkend="monitoring-pg-stat-toast-view"/>).
 
  </para>
  </sect2>
diff --git a/src/backend/access/table/toast_helper.c b/src/backend/access/table/toast_helper.c
index 0cc5a30f9b..98d10a0670 100644
--- a/src/backend/access/table/toast_helper.c
+++ b/src/backend/access/table/toast_helper.c
@@ -19,7 +19,9 @@
 #include "access/toast_helper.h"
 #include "access/toast_internals.h"
 #include "catalog/pg_type_d.h"
+#include "pgstat.h"
 
+PGDLLIMPORT bool pgstat_track_toast;
 
 /*
  * Prepare to TOAST a tuple.
@@ -229,7 +231,12 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 	Datum	   *value = &ttc->ttc_values[attribute];
 	Datum		new_value;
 	ToastAttrInfo *attr = &ttc->ttc_attr[attribute];
+	instr_time	start_time;
 
+	if (pgstat_track_toast)
+	{
+		INSTR_TIME_SET_CURRENT(start_time);
+	}
 	new_value = toast_compress_datum(*value, attr->tai_compression);
 
 	if (DatumGetPointer(new_value) != NULL)
@@ -239,6 +246,15 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 			pfree(DatumGetPointer(*value));
 		*value = new_value;
 		attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
+		if (pgstat_track_toast)
+		{
+			pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							attr->tai_size,
+							VARSIZE(DatumGetPointer(*value)),
+							start_time);
+		}
 		attr->tai_size = VARSIZE(DatumGetPointer(*value));
 		ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
 	}
@@ -246,6 +262,15 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 	{
 		/* incompressible, ignore on subsequent compression passes */
 		attr->tai_colflags |= TOASTCOL_INCOMPRESSIBLE;
+		if (pgstat_track_toast)
+		{
+			pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							0,
+							0,
+							start_time);
+		}
 	}
 }
 
@@ -258,6 +283,12 @@ toast_tuple_externalize(ToastTupleContext *ttc, int attribute, int options)
 	Datum	   *value = &ttc->ttc_values[attribute];
 	Datum		old_value = *value;
 	ToastAttrInfo *attr = &ttc->ttc_attr[attribute];
+	instr_time	start_time;
+
+	if (pgstat_track_toast)
+	{
+		INSTR_TIME_SET_CURRENT(start_time);
+	}
 
 	attr->tai_colflags |= TOASTCOL_IGNORE;
 	*value = toast_save_datum(ttc->ttc_rel, old_value, attr->tai_oldexternal,
@@ -266,6 +297,15 @@ toast_tuple_externalize(ToastTupleContext *ttc, int attribute, int options)
 		pfree(DatumGetPointer(old_value));
 	attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
 	ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
+	if (pgstat_track_toast)
+	{
+		pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							true,
+							false,
+							0,
+							0,
+							start_time);
+}
 }
 
 /*
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index bd48ee7bd2..000ece6bc3 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -1041,6 +1041,26 @@ CREATE VIEW pg_stat_user_functions AS
     WHERE P.prolang != 12  -- fast check to eliminate built-in functions
           AND pg_stat_get_function_calls(P.oid) IS NOT NULL;
 
+
+CREATE OR REPLACE VIEW pg_stat_toast AS
+ SELECT
+    n.nspname AS schemaname,
+    a.attrelid AS reloid,
+    a.attnum AS attnum,
+    c.relname AS relname,
+    a.attname AS attname,
+    attstorage AS storagemethod,
+    pg_stat_get_toast_externalizations(a.attrelid,a.attnum) AS externalized,
+    attcompression AS compressmethod,
+    pg_stat_get_toast_compressions(a.attrelid,a.attnum) AS compressattempts,
+    pg_stat_get_toast_compressionsuccesses(a.attrelid,a.attnum) AS compresssuccesses,
+    pg_stat_get_toast_compressedsizesum(a.attrelid,a.attnum) AS compressedsize,
+    pg_stat_get_toast_originalsizesum(a.attrelid,a.attnum) AS originalsize,
+    pg_stat_get_toast_total_time(a.attrelid,a.attnum) AS total_time
+   FROM pg_attribute a
+   JOIN pg_class c ON c.oid = a.attrelid
+   LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
+  WHERE pg_stat_get_toast_externalizations(a.attrelid,a.attnum) IS NOT NULL;
 CREATE VIEW pg_stat_xact_user_functions AS
     SELECT
             P.oid AS funcid,
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 1e7adc27b9..935c719946 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -116,7 +116,7 @@ static void pgstat_reset_subscription(PgStat_StatSubEntry *subentry, TimestampTz
 static void pgstat_write_statsfiles(bool permanent, bool allDbs);
 static void pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent);
 static HTAB *pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep);
-static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 									 bool permanent);
 static void backend_read_statsfile(void);
 
@@ -159,6 +159,7 @@ static void pgstat_recv_replslot(PgStat_MsgReplSlot *msg, int len);
 static void pgstat_recv_tempfile(PgStat_MsgTempFile *msg, int len);
 static void pgstat_recv_subscription_drop(PgStat_MsgSubscriptionDrop *msg, int len);
 static void pgstat_recv_subscription_error(PgStat_MsgSubscriptionError *msg, int len);
+static void pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len);
 
 
 /* ----------
@@ -168,7 +169,6 @@ static void pgstat_recv_subscription_error(PgStat_MsgSubscriptionError *msg, int
 
 bool		pgstat_track_counts = false;
 
-
 /* ----------
  * Built from GUC parameter
  * ----------
@@ -972,6 +972,9 @@ pgstat_report_stat(bool disconnect)
 	/* Now, send function statistics */
 	pgstat_send_funcstats();
 
+	/* Now, send TOAST statistics */
+	pgstat_send_toaststats();
+
 	/* Send WAL statistics */
 	pgstat_send_wal(true);
 
@@ -1494,6 +1497,35 @@ pgstat_fetch_stat_funcentry(Oid func_id)
 	return funcentry;
 }
 
+/* ----------
+ * pgstat_fetch_stat_toastentry() -
+ *
+ *	Support function for the SQL-callable pgstat* functions. Returns
+ *	the collected statistics for one TOAST attribute or NULL.
+ * ----------
+ */
+PgStat_StatToastEntry *
+pgstat_fetch_stat_toastentry(Oid rel_id, int attr)
+{
+	PgStat_StatDBEntry *dbentry;
+	PgStat_BackendAttrIdentifier toast_id = { rel_id, attr };
+	PgStat_StatToastEntry *toastentry = NULL;
+
+	/* load the stats file if needed */
+	backend_read_statsfile();
+
+	/* Lookup our database, then find the requested TOAST activity stats.  */
+	dbentry = pgstat_fetch_stat_dbentry(MyDatabaseId);
+	if (dbentry != NULL && dbentry->toastactivity != NULL)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &toast_id,
+														 HASH_FIND, NULL);
+	}
+
+	return toastentry;
+}
+
 /*
  * ---------
  * pgstat_fetch_stat_archiver() -
@@ -1914,6 +1946,10 @@ PgstatCollectorMain(int argc, char *argv[])
 					pgstat_recv_funcpurge(&msg.msg_funcpurge, len);
 					break;
 
+				case PGSTAT_MTYPE_TOASTSTAT:
+					pgstat_recv_toaststat(&msg.msg_toaststat, len);
+					break;
+
 				case PGSTAT_MTYPE_RECOVERYCONFLICT:
 					pgstat_recv_recoveryconflict(&msg.msg_recoveryconflict,
 												 len);
@@ -2050,6 +2086,13 @@ reset_dbentry_counters(PgStat_StatDBEntry *dbentry)
 									 PGSTAT_FUNCTION_HASH_SIZE,
 									 &hash_ctl,
 									 HASH_ELEM | HASH_BLOBS);
+
+	hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+	hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+	dbentry->toastactivity = hash_create("Per-database TOAST",
+									 PGSTAT_TOAST_HASH_SIZE,
+									 &hash_ctl,
+									 HASH_ELEM | HASH_BLOBS);
 }
 
 /*
@@ -2359,7 +2402,7 @@ pgstat_write_statsfiles(bool permanent, bool allDbs)
 	while ((dbentry = (PgStat_StatDBEntry *) hash_seq_search(&hstat)) != NULL)
 	{
 		/*
-		 * Write out the table and function stats for this DB into the
+		 * Write out the table, function and TOAST stats for this DB into the
 		 * appropriate per-DB stat file, if required.
 		 */
 		if (allDbs || pgstat_db_requested(dbentry->databaseid))
@@ -2490,8 +2533,10 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 {
 	HASH_SEQ_STATUS tstat;
 	HASH_SEQ_STATUS fstat;
+	HASH_SEQ_STATUS ostat;
 	PgStat_StatTabEntry *tabentry;
 	PgStat_StatFuncEntry *funcentry;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpout;
 	int32		format_id;
 	Oid			dbid = dbentry->databaseid;
@@ -2546,6 +2591,17 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 		(void) rc;				/* we'll check for error with ferror */
 	}
 
+	/*
+	 * Walk through the database's TOAST stats table.
+	 */
+	hash_seq_init(&ostat, dbentry->toastactivity);
+	while ((toastentry = (PgStat_StatToastEntry *) hash_seq_search(&ostat)) != NULL)
+	{
+		fputc('O', fpout);
+		rc = fwrite(toastentry, sizeof(PgStat_StatToastEntry), 1, fpout);
+		(void) rc;				/* we'll check for error with ferror */
+	}
+
 	/*
 	 * No more output to be done. Close the temp file and replace the old
 	 * pgstat.stat with it.  The ferror() check replaces testing for error
@@ -2784,6 +2840,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 				memcpy(dbentry, &dbbuf, sizeof(PgStat_StatDBEntry));
 				dbentry->tables = NULL;
 				dbentry->functions = NULL;
+				dbentry->toastactivity = NULL;
 
 				/*
 				 * In the collector, disregard the timestamp we read from the
@@ -2821,6 +2878,14 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 												 &hash_ctl,
 												 HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
 
+				hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+				hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+				hash_ctl.hcxt = pgStatLocalContext;
+				dbentry->toastactivity = hash_create("Per-database toast information",
+												 PGSTAT_TOAST_HASH_SIZE,
+												 &hash_ctl,
+												 HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
+
 				/*
 				 * If requested, read the data from the database-specific
 				 * file.  Otherwise we just leave the hashtables empty.
@@ -2829,6 +2894,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 					pgstat_read_db_statsfile(dbentry->databaseid,
 											 dbentry->tables,
 											 dbentry->functions,
+											 dbentry->toastactivity,
 											 permanent);
 
 				break;
@@ -2951,13 +3017,15 @@ done:
  * ----------
  */
 static void
-pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 						 bool permanent)
 {
 	PgStat_StatTabEntry *tabentry;
 	PgStat_StatTabEntry tabbuf;
 	PgStat_StatFuncEntry funcbuf;
 	PgStat_StatFuncEntry *funcentry;
+	PgStat_StatToastEntry toastbuf;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpin;
 	int32		format_id;
 	bool		found;
@@ -3071,6 +3139,32 @@ pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
 				memcpy(funcentry, &funcbuf, sizeof(funcbuf));
 				break;
 
+
+				/*
+				 * 'O'	A PgStat_StatToastEntry follows (tOast)
+				 */
+			case 'O':
+				if (fread(&toastbuf, 1, sizeof(PgStat_StatToastEntry),
+						  fpin) != sizeof(PgStat_StatToastEntry))
+				{
+					ereport(pgStatRunningInCollector ? LOG : WARNING,
+							(errmsg("corrupted statistics file \"%s\"",
+									statfile)));
+					goto done;
+				}
+
+				/*
+				 * Skip if TOAST data not wanted.
+				 */
+				if (toasthash == NULL)
+					break;
+
+				toastentry = (PgStat_StatToastEntry *) hash_search(toasthash,
+																 (void *) &toastbuf.t_id,
+																 HASH_ENTER, &found);
+				memcpy(toastentry, &toastbuf, sizeof(toastbuf));
+				break;
+
 				/*
 				 * 'E'	The EOF marker of a complete stats file.
 				 */
@@ -3745,6 +3839,8 @@ pgstat_recv_dropdb(PgStat_MsgDropdb *msg, int len)
 			hash_destroy(dbentry->tables);
 		if (dbentry->functions != NULL)
 			hash_destroy(dbentry->functions);
+		if (dbentry->toastactivity != NULL)
+			hash_destroy(dbentry->toastactivity);
 
 		if (hash_search(pgStatDBHash,
 						(void *) &dbid,
@@ -3781,7 +3877,8 @@ pgstat_recv_resetcounter(PgStat_MsgResetcounter *msg, int len)
 		hash_destroy(dbentry->tables);
 	if (dbentry->functions != NULL)
 		hash_destroy(dbentry->functions);
-
+	if (dbentry->toastactivity != NULL)
+		hash_destroy(dbentry->toastactivity);
 	dbentry->tables = NULL;
 	dbentry->functions = NULL;
 
@@ -4444,6 +4541,60 @@ pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len)
 	}
 }
 
+/* ----------
+ * pgstat_recv_toaststat() -
+ *
+ *	Count what the backend has done.
+ * ----------
+ */
+static void
+pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len)
+{
+	PgStat_ToastEntry *toastmsg = &(msg->m_entry[0]);
+	PgStat_StatDBEntry *dbentry;
+	PgStat_StatToastEntry *toastentry;
+	int			i;
+	bool		found;
+
+	dbentry = pgstat_get_db_entry(msg->m_databaseid, true);
+
+	/*
+	 * Process all TOAST entries in the message.
+	 */
+	for (i = 0; i < msg->m_nentries; i++, toastmsg++)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &(toastmsg->attr),
+														 HASH_ENTER, &found);
+
+		if (!found)
+		{
+			/*
+			 * If it's a new entry, initialize counters to the values
+			 * we just got.
+			 */
+			toastentry->t_numexternalized = toastmsg->t_numexternalized;
+			toastentry->t_numcompressed = toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess = toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_orig = toastmsg->t_size_orig;
+			toastentry->t_size_compressed = toastmsg->t_size_compressed;
+			toastentry->t_comp_time = toastmsg->t_comp_time;
+		}
+		else
+		{
+			/*
+			 * Otherwise add the values to the existing entry.
+			 */
+			toastentry->t_numexternalized += toastmsg->t_numexternalized;
+			toastentry->t_numcompressed += toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess += toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_orig += toastmsg->t_size_orig;
+			toastentry->t_size_compressed += toastmsg->t_size_compressed;
+			toastentry->t_comp_time += toastmsg->t_comp_time;
+		}
+	}
+}
+
 /* ----------
  * pgstat_recv_subscription_drop() -
  *
diff --git a/src/backend/utils/activity/Makefile b/src/backend/utils/activity/Makefile
index 25a967ab7d..229cdaefd3 100644
--- a/src/backend/utils/activity/Makefile
+++ b/src/backend/utils/activity/Makefile
@@ -26,6 +26,7 @@ OBJS = \
 	pgstat_subscription.o \
 	pgstat_wal.o \
 	pgstat_slru.o \
+	pgstat_toast.o \
 	wait_event.o
 
 include $(top_srcdir)/src/backend/common.mk
diff --git a/src/backend/utils/activity/pgstat_toast.c b/src/backend/utils/activity/pgstat_toast.c
new file mode 100644
index 0000000000..b6ba62c302
--- /dev/null
+++ b/src/backend/utils/activity/pgstat_toast.c
@@ -0,0 +1,157 @@
+/* -------------------------------------------------------------------------
+ *
+ * pgstat_toast.c
+ *	  Implementation of TOAST statistics.
+ *
+ * This file contains the implementation of TOAST statistics. It is kept
+ * separate from pgstat.c to enforce the line between the statistics access /
+ * storage implementation and the details about individual types of
+ * statistics.
+ *
+ * Copyright (c) 2001-2022, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/activity/pgstat_toast.c
+ * -------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "utils/pgstat_internal.h"
+#include "utils/timestamp.h"
+
+/*
+ * Indicates if backend has some function stats that it hasn't yet
+ * sent to the collector.
+ */
+bool		have_toast_stats = false;
+
+/*
+ * Backends store per-toast-column info that's waiting to be sent to the collector
+ * in this hash table (indexed by column's PgStat_BackendAttrIdentifier).
+ */
+static HTAB *pgStatToastActions = NULL;
+
+/*
+ * Report TOAST activity
+ * Called by toast_helper functions.
+ */
+void
+pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							instr_time start_time)
+{
+	PgStat_BackendAttrIdentifier toastattr = { relid, attr };
+	PgStat_BackendToastEntry *htabent;
+	instr_time	time_spent;
+	bool		found;
+
+	if (pgStatSock == PGINVALID_SOCKET || !pgstat_track_toast)
+		return;
+
+	INSTR_TIME_SET_CURRENT(time_spent);
+	INSTR_TIME_SUBTRACT(time_spent, start_time);
+
+	if (!pgStatToastActions)
+	{
+		/* First time through - initialize toast stat table */
+		HASHCTL		hash_ctl;
+
+		hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+		hash_ctl.entrysize = sizeof(PgStat_BackendToastEntry);
+		pgStatToastActions = hash_create("TOAST stat entries",
+									  PGSTAT_TOAST_HASH_SIZE,
+									  &hash_ctl,
+									  HASH_ELEM | HASH_BLOBS);
+	}
+
+	/* Get the stats entry for this TOAST attribute, create if necessary */
+	htabent = hash_search(pgStatToastActions, &toastattr,
+						  HASH_ENTER, &found);
+	if (!found)
+	{
+		MemSet(&htabent->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	/* update counters */
+	if (externalized)
+	{
+		htabent->t_counts.t_numexternalized++;
+	}
+	if (compressed)
+	{
+		htabent->t_counts.t_numcompressed++;
+		htabent->t_counts.t_size_orig+=old_size;
+		if (new_size)
+		{
+			htabent->t_counts.t_numcompressionsuccess++;
+			htabent->t_counts.t_size_compressed+=new_size;
+		}
+	}
+	/* record time spent */
+	INSTR_TIME_ADD(htabent->t_counts.t_comp_time, time_spent);
+
+	/* indicate that we have something to send */
+	have_toast_stats = true;
+}
+
+/*
+ * Subroutine for pgstat_report_stat: populate and send a toast stat message
+ */
+void
+pgstat_send_toaststats(void)
+{
+	static const PgStat_ToastCounts all_zeroes;
+
+	PgStat_MsgToaststat msg;
+	PgStat_BackendToastEntry *entry;
+	HASH_SEQ_STATUS tstat;
+
+	if (pgStatToastActions == NULL)
+		return;
+
+	pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_TOASTSTAT);
+	msg.m_databaseid = MyDatabaseId;
+	msg.m_nentries = 0;
+
+	hash_seq_init(&tstat, pgStatToastActions);
+	while ((entry = (PgStat_BackendToastEntry *) hash_seq_search(&tstat)) != NULL)
+	{
+		PgStat_ToastEntry *m_ent;
+
+		/* Skip it if no counts accumulated since last time */
+		if (memcmp(&entry->t_counts, &all_zeroes,
+				   sizeof(PgStat_ToastCounts)) == 0)
+			continue;
+
+		/* need to convert format of time accumulators */
+		m_ent = &msg.m_entry[msg.m_nentries];
+		m_ent->attr = entry->attr;
+		m_ent->t_numexternalized = entry->t_counts.t_numexternalized;
+		m_ent->t_numcompressed = entry->t_counts.t_numcompressed;
+		m_ent->t_numcompressionsuccess = entry->t_counts.t_numcompressionsuccess;
+		m_ent->t_size_orig = entry->t_counts.t_size_orig;
+		m_ent->t_size_compressed = entry->t_counts.t_size_compressed;
+		m_ent->t_comp_time = INSTR_TIME_GET_MICROSEC(entry->t_counts.t_comp_time);
+
+		if (++msg.m_nentries >= PGSTAT_NUM_TOASTENTRIES)
+		{
+			pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+						msg.m_nentries * sizeof(PgStat_ToastEntry));
+			msg.m_nentries = 0;
+		}
+
+		/* reset the entry's counts */
+		MemSet(&entry->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	if (msg.m_nentries > 0)
+		pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+					msg.m_nentries * sizeof(PgStat_ToastEntry));
+
+	have_toast_stats = false;
+}
+
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index eff45b16f2..203c279795 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -410,6 +410,78 @@ pg_stat_get_function_self_time(PG_FUNCTION_ARGS)
 	PG_RETURN_FLOAT8(((double) funcentry->f_self_time) / 1000.0);
 }
 
+Datum
+pg_stat_get_toast_externalizations(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numexternalized);
+}
+
+Datum
+pg_stat_get_toast_compressions(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressed);
+}
+
+Datum
+pg_stat_get_toast_compressionsuccesses(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressionsuccess);
+}
+
+Datum
+pg_stat_get_toast_originalsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_orig);
+}
+
+Datum
+pg_stat_get_toast_compressedsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_compressed);
+}
+
+Datum
+pg_stat_get_toast_total_time(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_comp_time);
+}
+
 Datum
 pg_stat_get_backend_idset(PG_FUNCTION_ARGS)
 {
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index e7f0a380e6..4b29836656 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -1546,6 +1546,15 @@ static struct config_bool ConfigureNamesBool[] =
 		true,
 		NULL, NULL, NULL
 	},
+	{
+		{"track_toast", PGC_SUSET, STATS_COLLECTOR,
+			gettext_noop("Collects statistics on TOAST activity."),
+			NULL
+		},
+		&pgstat_track_toast,
+		false,
+		NULL, NULL, NULL
+	},
 	{
 		{"track_io_timing", PGC_SUSET, STATS_COLLECTOR,
 			gettext_noop("Collects timing statistics for database I/O activity."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 4cf5b26a36..002569fde6 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -611,6 +611,7 @@
 #track_io_timing = off
 #track_wal_io_timing = off
 #track_functions = none			# none, pl, all
+#track_toast = off
 #stats_temp_directory = 'pg_stat_tmp'
 
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index d8e8715ed1..5ce9667b0b 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5673,6 +5673,31 @@
   proparallel => 'r', prorettype => 'float8', proargtypes => 'oid',
   prosrc => 'pg_stat_get_function_self_time' },
 
+{ oid => '9700', descr => 'statistics: number of TOAST externalizations',
+  proname => 'pg_stat_get_toast_externalizations', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_externalizations' },
+{ oid => '9701', descr => 'statistics: number of TOAST compressions',
+  proname => 'pg_stat_get_toast_compressions', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressions' },
+  { oid => '9702', descr => 'statistics: number of successful TOAST compressions',
+  proname => 'pg_stat_get_toast_compressionsuccesses', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressionsuccesses' },
+{ oid => '9703', descr => 'statistics: total original size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_originalsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_originalsizesum' },
+{ oid => '9704', descr => 'statistics: total compressed size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_compressedsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressedsizesum' },
+{ oid => '9705', descr => 'statistics: total time spend TOASTing data',
+  proname => 'pg_stat_get_toast_total_time', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_total_time' },
+
 { oid => '3037',
   descr => 'statistics: number of scans done for table/index in current transaction',
   proname => 'pg_stat_get_xact_numscans', provolatile => 'v',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 534d595ca0..7c8191aefe 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -33,7 +33,6 @@
 /* Default directory to store temporary statistics data in */
 #define PG_STAT_TMP_DIR		"pg_stat_tmp"
 
-
 /* Values for track_functions GUC variable --- order is significant! */
 typedef enum TrackFunctionsLevel
 {
@@ -252,6 +251,7 @@ typedef enum StatMsgType
 	PGSTAT_MTYPE_DISCONNECT,
 	PGSTAT_MTYPE_SUBSCRIPTIONDROP,
 	PGSTAT_MTYPE_SUBSCRIPTIONERROR,
+	PGSTAT_MTYPE_TOASTSTAT,
 } StatMsgType;
 
 /* ----------
@@ -726,6 +726,80 @@ typedef struct PgStat_MsgDisconnect
 	SessionEndType m_cause;
 } PgStat_MsgDisconnect;
 
+/* ----------
+ * PgStat_BackendAttrIdentifier	Identifier for a single attribute/column (OID + attr)
+ * Used as a hashable identifier for (e.g.) TOAST columns
+ * ----------
+ */
+typedef struct PgStat_BackendAttrIdentifier
+{
+	Oid			relid;
+	int			attr;
+} PgStat_BackendAttrIdentifier;
+
+/* ----------
+ * PgStat_ToastCounts	The actual per-TOAST counts kept by a backend
+ *
+ * This struct should contain only actual event counters, because we memcmp
+ * it against zeroes to detect whether there are any counts to transmit.
+ *
+ * Note that the time counters are in instr_time format here.  We convert to
+ * microseconds in PgStat_Counter format when transmitting to the collector.
+ * ----------
+ */
+typedef struct PgStat_ToastCounts
+{
+	PgStat_Counter	t_numexternalized;
+	PgStat_Counter	t_numcompressed;
+	PgStat_Counter	t_numcompressionsuccess;
+	uint64		t_size_orig;
+	uint64		t_size_compressed;
+	instr_time	t_comp_time;
+} PgStat_ToastCounts;
+
+/* ----------
+ * PgStat_BackendToastEntry	Entry in backend's per-toast-attr hash table
+ * ----------
+ */
+typedef struct PgStat_BackendToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_ToastCounts 		t_counts;
+} PgStat_BackendToastEntry;
+
+/* ----------
+ * PgStat_ToastEntry			Per-TOAST-column info in a MsgToaststat
+ * ----------
+ */
+typedef struct PgStat_ToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_Counter 			t_numexternalized;
+	PgStat_Counter 			t_numcompressed;
+	PgStat_Counter 			t_numcompressionsuccess;
+	uint64		   		t_size_orig;
+	uint64		   		t_size_compressed;
+	PgStat_Counter			t_comp_time;	/* time in microseconds */
+} PgStat_ToastEntry;
+
+/* ----------
+ * PgStat_MsgToaststat			Sent by the backend to report function
+ *								usage statistics.
+ * ----------
+ */
+#define PGSTAT_NUM_TOASTENTRIES	\
+	((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - sizeof(int))  \
+	 / sizeof(PgStat_ToastEntry))
+
+typedef struct PgStat_MsgToaststat
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+	int			m_nentries;
+	PgStat_ToastEntry m_entry[PGSTAT_NUM_TOASTENTRIES];
+} PgStat_MsgToaststat;
+
+
 /* ----------
  * PgStat_Msg					Union over all possible messages.
  * ----------
@@ -754,6 +828,7 @@ typedef union PgStat_Msg
 	PgStat_MsgSLRU msg_slru;
 	PgStat_MsgFuncstat msg_funcstat;
 	PgStat_MsgFuncpurge msg_funcpurge;
+	PgStat_MsgToaststat msg_toaststat;
 	PgStat_MsgRecoveryConflict msg_recoveryconflict;
 	PgStat_MsgDeadlock msg_deadlock;
 	PgStat_MsgTempFile msg_tempfile;
@@ -774,7 +849,7 @@ typedef union PgStat_Msg
  * ------------------------------------------------------------
  */
 
-#define PGSTAT_FILE_FORMAT_ID	0x01A5BCA6
+#define PGSTAT_FILE_FORMAT_ID	0x01A5BCA7
 
 /*
  * Archiver statistics kept in the stats collector
@@ -864,6 +939,7 @@ typedef struct PgStat_StatDBEntry
 	 */
 	HTAB	   *tables;
 	HTAB	   *functions;
+	HTAB	   *toastactivity;
 } PgStat_StatDBEntry;
 
 /* ----------
@@ -936,6 +1012,22 @@ typedef struct PgStat_StatSubEntry
 } PgStat_StatSubEntry;
 
 /* ----------
+ * PgStat_StatToastEntry			The collector's data per TOAST attribute
+ * ----------
+ */
+typedef struct PgStat_StatToastEntry
+{
+	PgStat_BackendAttrIdentifier t_id;
+	PgStat_Counter t_numexternalized;
+	PgStat_Counter t_numcompressed;
+	PgStat_Counter t_numcompressionsuccess;
+	uint64		   t_size_orig;
+	uint64		   t_size_compressed;
+	PgStat_Counter t_comp_time;	/* time in microseconds */
+} PgStat_StatToastEntry;
+
+
+/*
  * PgStat_StatTabEntry			The collector's data per table (or index)
  * ----------
  */
@@ -1027,6 +1119,7 @@ extern PgStat_BgWriterStats *pgstat_fetch_stat_bgwriter(void);
 extern PgStat_CheckpointerStats *pgstat_fetch_stat_checkpointer(void);
 extern PgStat_StatDBEntry *pgstat_fetch_stat_dbentry(Oid dbid);
 extern PgStat_StatFuncEntry *pgstat_fetch_stat_funcentry(Oid funcid);
+extern PgStat_StatToastEntry *pgstat_fetch_stat_toastentry(Oid rel_id, int attr);
 extern PgStat_GlobalStats *pgstat_fetch_global(void);
 extern PgStat_StatReplSlotEntry *pgstat_fetch_replslot(NameData slotname);
 extern PgStat_StatSubEntry *pgstat_fetch_stat_subscription(Oid subid);
@@ -1090,6 +1183,7 @@ extern void pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu,
 extern PgStat_BackendFunctionEntry *find_funcstat_entry(Oid func_id);
 
 
+
 /*
  * Functions in pgstat_relation.c
  */
@@ -1199,6 +1293,17 @@ extern void pgstat_report_subscription_drop(Oid subid);
 
 extern void pgstat_send_wal(bool force);
 
+/*
+ * Functions in pgstat_toast.c
+ */
+
+extern void pgstat_send_toaststats(void);
+extern void pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							instr_time start_time);
 
 /*
  * Variables in pgstat.c
@@ -1207,6 +1312,7 @@ extern void pgstat_send_wal(bool force);
 /* GUC parameters */
 extern PGDLLIMPORT bool pgstat_track_counts;
 extern PGDLLIMPORT int pgstat_track_functions;
+extern PGDLLIMPORT bool pgstat_track_toast;
 extern char *pgstat_stat_directory;
 extern char *pgstat_stat_tmpname;
 extern char *pgstat_stat_filename;
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index abbb4f8d96..44b0aeb7af 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -27,6 +27,7 @@
 #define PGSTAT_DB_HASH_SIZE		16
 #define PGSTAT_TAB_HASH_SIZE	512
 #define PGSTAT_FUNCTION_HASH_SIZE	512
+#define PGSTAT_TOAST_HASH_SIZE	64
 #define PGSTAT_SUBSCRIPTION_HASH_SIZE	32
 #define PGSTAT_REPLSLOT_HASH_SIZE	32
 
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index 6cb6388880..9b663f0645 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -2114,6 +2114,23 @@ pg_stat_sys_tables| SELECT pg_stat_all_tables.relid,
     pg_stat_all_tables.autoanalyze_count
    FROM pg_stat_all_tables
   WHERE ((pg_stat_all_tables.schemaname = ANY (ARRAY['pg_catalog'::name, 'information_schema'::name])) OR (pg_stat_all_tables.schemaname ~ '^pg_toast'::text));
+pg_stat_toast| SELECT n.nspname AS schemaname,
+    a.attrelid AS reloid,
+    a.attnum,
+    c.relname,
+    a.attname,
+    a.attstorage AS storagemethod,
+    pg_stat_get_toast_externalizations(a.attrelid, (a.attnum)::integer) AS externalized,
+    a.attcompression AS compressmethod,
+    pg_stat_get_toast_compressions(a.attrelid, (a.attnum)::integer) AS compressattempts,
+    pg_stat_get_toast_compressionsuccesses(a.attrelid, (a.attnum)::integer) AS compresssuccesses,
+    pg_stat_get_toast_compressedsizesum(a.attrelid, (a.attnum)::integer) AS compressedsize,
+    pg_stat_get_toast_originalsizesum(a.attrelid, (a.attnum)::integer) AS originalsize,
+    pg_stat_get_toast_total_time(a.attrelid, (a.attnum)::integer) AS total_time
+   FROM ((pg_attribute a
+     JOIN pg_class c ON ((c.oid = a.attrelid)))
+     LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace)))
+  WHERE (pg_stat_get_toast_externalizations(a.attrelid, (a.attnum)::integer) IS NOT NULL);
 pg_stat_user_functions| SELECT p.oid AS funcid,
     n.nspname AS schemaname,
     p.proname AS funcname,
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index b7416c8f8f..da8631f7b1 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -11,6 +11,32 @@ SHOW track_counts;  -- must be on
  on
 (1 row)
 
+-- prepare and fill the pg_stat_toast table now:
+SHOW track_toast;
+ track_toast 
+-------------
+ off
+(1 row)
+
+SET track_toast TO on;
+SHOW track_toast;
+ track_toast 
+-------------
+ on
+(1 row)
+
+TABLE pg_stat_toast; -- view exists
+ schemaname | reloid | attnum | relname | attname | storagemethod | externalized | compressmethod | compressattempts | compresssuccesses | compressedsize | originalsize | total_time 
+------------+--------+--------+---------+---------+---------------+--------------+----------------+------------------+-------------------+----------------+--------------+------------
+(0 rows)
+
+CREATE TABLE toast_test (cola TEXT, colb TEXT, colc TEXT , cold TEXT);
+ALTER TABLE toast_test ALTER colb SET STORAGE EXTERNAL;
+ALTER TABLE toast_test ALTER colc SET STORAGE MAIN;
+ALTER TABLE toast_test ALTER cold SET STORAGE PLAIN;
+INSERT INTO toast_test VALUES (repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100) );
+-- make sure we don't interfere with the other tests:
+SET track_toast TO off;
 -- ensure that both seqscan and indexscan plans are allowed
 SET enable_seqscan TO on;
 SET enable_indexscan TO on;
@@ -255,4 +281,40 @@ SELECT pg_stat_get_tuples_hot_updated('brin_hot'::regclass::oid);
 
 DROP TABLE brin_hot;
 DROP FUNCTION wait_for_hot_stats();
+-- now check that the track_toast stuff worked:
+SELECT attname
+	,storagemethod
+	,externalized
+	,compressmethod
+	,compressattempts
+	,compresssuccesses
+	,compressedsize < originalsize AS compression_works
+	, total_time > 0 AS takes_time
+FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY attname;
+ attname | storagemethod | externalized | compressmethod | compressattempts | compresssuccesses | compression_works | takes_time 
+---------+---------------+--------------+----------------+------------------+-------------------+-------------------+------------
+ cola    | x             |            1 |                |                1 |                 1 | t                 | t
+ colb    | e             |            1 |                |                0 |                 0 | f                 | t
+ colc    | m             |            0 |                |                1 |                 1 | t                 | t
+(3 rows)
+
+SELECT compressattempts=0 AS external_doesnt_compress FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'e';
+ external_doesnt_compress 
+--------------------------
+ t
+(1 row)
+
+SELECT externalized=0 AS main_doesnt_externalize FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'm';
+ main_doesnt_externalize 
+-------------------------
+ t
+(1 row)
+
+DROP TABLE toast_test;
+SELECT count(*) FROM pg_stat_toast WHERE relname = 'toast_test';
+ count 
+-------
+     0
+(1 row)
+
 -- End of Stats Test
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index dbc2dd28b6..81890d1238 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -8,6 +8,20 @@
 -- conditio sine qua non
 SHOW track_counts;  -- must be on
 
+-- prepare and fill the pg_stat_toast table now:
+SHOW track_toast;
+SET track_toast TO on;
+SHOW track_toast;
+TABLE pg_stat_toast; -- view exists
+
+CREATE TABLE toast_test (cola TEXT, colb TEXT, colc TEXT , cold TEXT);
+ALTER TABLE toast_test ALTER colb SET STORAGE EXTERNAL;
+ALTER TABLE toast_test ALTER colc SET STORAGE MAIN;
+ALTER TABLE toast_test ALTER cold SET STORAGE PLAIN;
+INSERT INTO toast_test VALUES (repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100) );
+-- make sure we don't interfere with the other tests:
+SET track_toast TO off;
+
 -- ensure that both seqscan and indexscan plans are allowed
 SET enable_seqscan TO on;
 SET enable_indexscan TO on;
@@ -228,5 +242,19 @@ SELECT pg_stat_get_tuples_hot_updated('brin_hot'::regclass::oid);
 DROP TABLE brin_hot;
 DROP FUNCTION wait_for_hot_stats();
 
+-- now check that the track_toast stuff worked:
+SELECT attname
+	,storagemethod
+	,externalized
+	,compressmethod
+	,compressattempts
+	,compresssuccesses
+	,compressedsize < originalsize AS compression_works
+	, total_time > 0 AS takes_time
+FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY attname;
+SELECT compressattempts=0 AS external_doesnt_compress FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'e';
+SELECT externalized=0 AS main_doesnt_externalize FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'm';
+DROP TABLE toast_test;
+SELECT count(*) FROM pg_stat_toast WHERE relname = 'toast_test';
 
 -- End of Stats Test

 doc/src/sgml/config.sgml                      |  26 ++++
 doc/src/sgml/monitoring.sgml                  | 163 ++++++++++++++++++++++++++
 doc/src/sgml/storage.sgml                     |  12 +-
 src/backend/access/table/toast_helper.c       |  40 +++++++
 src/backend/catalog/system_views.sql          |  20 ++++
 src/backend/postmaster/pgstat.c               | 161 ++++++++++++++++++++++++-
 src/backend/utils/activity/Makefile           |   1 +
 src/backend/utils/activity/pgstat_toast.c     | 157 +++++++++++++++++++++++++
 src/backend/utils/adt/pgstatfuncs.c           |  72 ++++++++++++
 src/backend/utils/misc/guc.c                  |   9 ++
 src/backend/utils/misc/postgresql.conf.sample |   1 +
 src/include/catalog/pg_proc.dat               |  25 ++++
 src/include/pgstat.h                          | 110 ++++++++++++++++-
 src/include/utils/pgstat_internal.h           |   1 +
 src/test/regress/expected/rules.out           |  17 +++
 src/test/regress/expected/stats.out           |  62 ++++++++++
 src/test/regress/sql/stats.sql                |  28 +++++
 17 files changed, 897 insertions(+), 8 deletions(-)

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 43e4ade83e..e6f0768472 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -7935,6 +7935,32 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv;
       </listitem>
      </varlistentry>
 
+     <varlistentry id="guc-track-toast" xreflabel="track_toast">
+      <term><varname>track_toast</varname> (<type>boolean</type>)
+      <indexterm>
+       <primary><varname>track_toast</varname> configuration parameter</primary>
+      </indexterm>
+      </term>
+      <listitem>
+       <para>
+        Enables tracking of <link linkend="storage-toast">TOAST</link> activities.
+        Compressions and externalizations are tracked.
+        The default is <literal>off</literal>.
+        Only superusers can change this setting.
+       </para>
+
+       <note>
+        <para>
+        Be aware that this feature, depending on the amount of TOASTable columns in
+        your databases, may significantly increase the size of the statistics files
+        and the workload of the statistics collector. It is recommended to only
+        temporarily activate this to assess the right compression and storage method
+        for a column.
+        </para>
+       </note>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="guc-stats-temp-directory" xreflabel="stats_temp_directory">
       <term><varname>stats_temp_directory</varname> (<type>string</type>)
       <indexterm>
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 3b9172f65b..cd0a5bea35 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -610,6 +610,17 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
       yet included in <structname>pg_stat_user_functions</structname>).</entry>
      </row>
 
+     <row>
+      <entry><structname>pg_stat_toast</structname><indexterm><primary>pg_stat_toast</primary></indexterm></entry>
+      <entry>
+       One row for each column that has ever been TOASTed (compressed and/or externalized).
+       Showing the number of externalizations, compression attempts / successes, compressed and
+       uncompressed sizes etc.
+       <link linkend="monitoring-pg-stat-toast-view">
+       <structname>pg_stat_toast</structname></link> for details.
+      </entry>
+     </row>
+
      <row>
       <entry><structname>pg_stat_slru</structname><indexterm><primary>pg_stat_slru</primary></indexterm></entry>
       <entry>One row per SLRU, showing statistics of operations. See
@@ -4946,6 +4957,158 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
 
  </sect2>
 
+ <sect2 id="monitoring-pg-stat-toast-view">
+  <title><structname>pg_stat_toast</structname></title>
+
+  <indexterm>
+   <primary>pg_stat_toast</primary>
+  </indexterm>
+
+  <para>
+   The <structname>pg_stat_toast</structname> view will contain
+   one row for each column of variable size that has been TOASTed since 
+   the last statistics reset. The <xref linkend="guc-track-toast"/> parameter
+   controls whether TOAST activities are tracked or not.
+  </para>
+
+  <table id="pg-stat-toast-view" xreflabel="pg_stat_toast">
+   <title><structname>pg_stat_toast</structname> View</title>
+   <tgroup cols="1">
+    <thead>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       Column Type
+      </para>
+      <para>
+       Description
+      </para></entry>
+     </row>
+    </thead>
+
+    <tbody>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>schemaname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the schema the relation is in
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>reloid</structfield> <type>oid</type>
+      </para>
+      <para>
+       OID of the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>attnum</structfield> <type>int</type>
+      </para>
+      <para>
+       Attribute (column) number in the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>relname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>attname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the attribute (column)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>storagemethod</structfield> <type>char</type>
+      </para>
+      <para>
+       Storage method of the attribute
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>externalized</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times this attribute was externalized (pushed to TOAST relation)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressmethod</structfield> <type>char</type>
+      </para>
+      <para>
+       Current compression method of the attribute (empty means default)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressattempts</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times compression of this attribute was attempted
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compresssuccesses</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times compression of this attribute was successful
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressedsize</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total size of all compressed datums
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>originalsize</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total size of all compressed datums before compression
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>total_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Total time spent TOASTing this attribute, in microseconds.
+      </para></entry>
+     </row>
+
+    </tbody>
+   </tgroup>
+  </table>
+
+ </sect2>
+
  <sect2 id="monitoring-pg-stat-slru-view">
   <title><structname>pg_stat_slru</structname></title>
 
diff --git a/doc/src/sgml/storage.sgml b/doc/src/sgml/storage.sgml
index f4b9f66589..d0e165d5f1 100644
--- a/doc/src/sgml/storage.sgml
+++ b/doc/src/sgml/storage.sgml
@@ -517,6 +517,15 @@ pages). There was no run time difference compared to an un-<acronym>TOAST</acron
 comparison table, in which all the HTML pages were cut down to 7 kB to fit.
 </para>
 
+<para>
+When you enable <xref linkend="guc-track-toast"/>, the system view
+<link linkend="monitoring-pg-stat-toast-view"><structname>pg_stat_toast</structname>
+</link> provides details on the number and effect of compression attempts,
+number of externalizations and some more useful information that enables you
+to decide if a different storage method and/or compression method would suite a
+column better.
+</para>
+
 </sect2>
 
 <sect2 id="storage-toast-inmemory">
@@ -1069,7 +1078,8 @@ data. Empty in ordinary tables.</entry>
   <type>struct varlena</type>, which includes the total length of the stored
   value and some flag bits.  Depending on the flags, the data can be either
   inline or in a <acronym>TOAST</acronym> table;
-  it might be compressed, too (see <xref linkend="storage-toast"/>).
+  it might be compressed, too (see <xref linkend="storage-toast"/> and 
+  <xref linkend="monitoring-pg-stat-toast-view"/>).
 
  </para>
  </sect2>
diff --git a/src/backend/access/table/toast_helper.c b/src/backend/access/table/toast_helper.c
index 0cc5a30f9b..98d10a0670 100644
--- a/src/backend/access/table/toast_helper.c
+++ b/src/backend/access/table/toast_helper.c
@@ -19,7 +19,9 @@
 #include "access/toast_helper.h"
 #include "access/toast_internals.h"
 #include "catalog/pg_type_d.h"
+#include "pgstat.h"
 
+PGDLLIMPORT bool pgstat_track_toast;
 
 /*
  * Prepare to TOAST a tuple.
@@ -229,7 +231,12 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 	Datum	   *value = &ttc->ttc_values[attribute];
 	Datum		new_value;
 	ToastAttrInfo *attr = &ttc->ttc_attr[attribute];
+	instr_time	start_time;
 
+	if (pgstat_track_toast)
+	{
+		INSTR_TIME_SET_CURRENT(start_time);
+	}
 	new_value = toast_compress_datum(*value, attr->tai_compression);
 
 	if (DatumGetPointer(new_value) != NULL)
@@ -239,6 +246,15 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 			pfree(DatumGetPointer(*value));
 		*value = new_value;
 		attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
+		if (pgstat_track_toast)
+		{
+			pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							attr->tai_size,
+							VARSIZE(DatumGetPointer(*value)),
+							start_time);
+		}
 		attr->tai_size = VARSIZE(DatumGetPointer(*value));
 		ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
 	}
@@ -246,6 +262,15 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 	{
 		/* incompressible, ignore on subsequent compression passes */
 		attr->tai_colflags |= TOASTCOL_INCOMPRESSIBLE;
+		if (pgstat_track_toast)
+		{
+			pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							0,
+							0,
+							start_time);
+		}
 	}
 }
 
@@ -258,6 +283,12 @@ toast_tuple_externalize(ToastTupleContext *ttc, int attribute, int options)
 	Datum	   *value = &ttc->ttc_values[attribute];
 	Datum		old_value = *value;
 	ToastAttrInfo *attr = &ttc->ttc_attr[attribute];
+	instr_time	start_time;
+
+	if (pgstat_track_toast)
+	{
+		INSTR_TIME_SET_CURRENT(start_time);
+	}
 
 	attr->tai_colflags |= TOASTCOL_IGNORE;
 	*value = toast_save_datum(ttc->ttc_rel, old_value, attr->tai_oldexternal,
@@ -266,6 +297,15 @@ toast_tuple_externalize(ToastTupleContext *ttc, int attribute, int options)
 		pfree(DatumGetPointer(old_value));
 	attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
 	ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
+	if (pgstat_track_toast)
+	{
+		pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							true,
+							false,
+							0,
+							0,
+							start_time);
+}
 }
 
 /*
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 9eaa51df29..e9cce5c51a 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -1066,6 +1066,26 @@ CREATE VIEW pg_stat_user_functions AS
     WHERE P.prolang != 12  -- fast check to eliminate built-in functions
           AND pg_stat_get_function_calls(P.oid) IS NOT NULL;
 
+
+CREATE OR REPLACE VIEW pg_stat_toast AS
+ SELECT
+    n.nspname AS schemaname,
+    a.attrelid AS reloid,
+    a.attnum AS attnum,
+    c.relname AS relname,
+    a.attname AS attname,
+    attstorage AS storagemethod,
+    pg_stat_get_toast_externalizations(a.attrelid,a.attnum) AS externalized,
+    attcompression AS compressmethod,
+    pg_stat_get_toast_compressions(a.attrelid,a.attnum) AS compressattempts,
+    pg_stat_get_toast_compressionsuccesses(a.attrelid,a.attnum) AS compresssuccesses,
+    pg_stat_get_toast_compressedsizesum(a.attrelid,a.attnum) AS compressedsize,
+    pg_stat_get_toast_originalsizesum(a.attrelid,a.attnum) AS originalsize,
+    pg_stat_get_toast_total_time(a.attrelid,a.attnum) AS total_time
+   FROM pg_attribute a
+   JOIN pg_class c ON c.oid = a.attrelid
+   LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
+  WHERE pg_stat_get_toast_externalizations(a.attrelid,a.attnum) IS NOT NULL;
 CREATE VIEW pg_stat_xact_user_functions AS
     SELECT
             P.oid AS funcid,
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index c10311e036..c4cf0a33fc 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -116,7 +116,7 @@ static void pgstat_reset_subscription(PgStat_StatSubEntry *subentry, TimestampTz
 static void pgstat_write_statsfiles(bool permanent, bool allDbs);
 static void pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent);
 static HTAB *pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep);
-static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 									 bool permanent);
 static void backend_read_statsfile(void);
 
@@ -159,6 +159,7 @@ static void pgstat_recv_replslot(PgStat_MsgReplSlot *msg, int len);
 static void pgstat_recv_tempfile(PgStat_MsgTempFile *msg, int len);
 static void pgstat_recv_subscription_drop(PgStat_MsgSubscriptionDrop *msg, int len);
 static void pgstat_recv_subscription_error(PgStat_MsgSubscriptionError *msg, int len);
+static void pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len);
 
 
 /* ----------
@@ -168,7 +169,6 @@ static void pgstat_recv_subscription_error(PgStat_MsgSubscriptionError *msg, int
 
 bool		pgstat_track_counts = false;
 
-
 /* ----------
  * Built from GUC parameter
  * ----------
@@ -972,6 +972,9 @@ pgstat_report_stat(bool disconnect)
 	/* Now, send function statistics */
 	pgstat_send_funcstats();
 
+	/* Now, send TOAST statistics */
+	pgstat_send_toaststats();
+
 	/* Send WAL statistics */
 	pgstat_send_wal(true);
 
@@ -1494,6 +1497,35 @@ pgstat_fetch_stat_funcentry(Oid func_id)
 	return funcentry;
 }
 
+/* ----------
+ * pgstat_fetch_stat_toastentry() -
+ *
+ *	Support function for the SQL-callable pgstat* functions. Returns
+ *	the collected statistics for one TOAST attribute or NULL.
+ * ----------
+ */
+PgStat_StatToastEntry *
+pgstat_fetch_stat_toastentry(Oid rel_id, int attr)
+{
+	PgStat_StatDBEntry *dbentry;
+	PgStat_BackendAttrIdentifier toast_id = { rel_id, attr };
+	PgStat_StatToastEntry *toastentry = NULL;
+
+	/* load the stats file if needed */
+	backend_read_statsfile();
+
+	/* Lookup our database, then find the requested TOAST activity stats.  */
+	dbentry = pgstat_fetch_stat_dbentry(MyDatabaseId);
+	if (dbentry != NULL && dbentry->toastactivity != NULL)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &toast_id,
+														 HASH_FIND, NULL);
+	}
+
+	return toastentry;
+}
+
 /*
  * ---------
  * pgstat_fetch_stat_archiver() -
@@ -1914,6 +1946,10 @@ PgstatCollectorMain(int argc, char *argv[])
 					pgstat_recv_funcpurge(&msg.msg_funcpurge, len);
 					break;
 
+				case PGSTAT_MTYPE_TOASTSTAT:
+					pgstat_recv_toaststat(&msg.msg_toaststat, len);
+					break;
+
 				case PGSTAT_MTYPE_RECOVERYCONFLICT:
 					pgstat_recv_recoveryconflict(&msg.msg_recoveryconflict,
 												 len);
@@ -2050,6 +2086,13 @@ reset_dbentry_counters(PgStat_StatDBEntry *dbentry)
 									 PGSTAT_FUNCTION_HASH_SIZE,
 									 &hash_ctl,
 									 HASH_ELEM | HASH_BLOBS);
+
+	hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+	hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+	dbentry->toastactivity = hash_create("Per-database TOAST",
+									 PGSTAT_TOAST_HASH_SIZE,
+									 &hash_ctl,
+									 HASH_ELEM | HASH_BLOBS);
 }
 
 /*
@@ -2359,7 +2402,7 @@ pgstat_write_statsfiles(bool permanent, bool allDbs)
 	while ((dbentry = (PgStat_StatDBEntry *) hash_seq_search(&hstat)) != NULL)
 	{
 		/*
-		 * Write out the table and function stats for this DB into the
+		 * Write out the table, function and TOAST stats for this DB into the
 		 * appropriate per-DB stat file, if required.
 		 */
 		if (allDbs || pgstat_db_requested(dbentry->databaseid))
@@ -2490,8 +2533,10 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 {
 	HASH_SEQ_STATUS tstat;
 	HASH_SEQ_STATUS fstat;
+	HASH_SEQ_STATUS ostat;
 	PgStat_StatTabEntry *tabentry;
 	PgStat_StatFuncEntry *funcentry;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpout;
 	int32		format_id;
 	Oid			dbid = dbentry->databaseid;
@@ -2546,6 +2591,17 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 		(void) rc;				/* we'll check for error with ferror */
 	}
 
+	/*
+	 * Walk through the database's TOAST stats table.
+	 */
+	hash_seq_init(&ostat, dbentry->toastactivity);
+	while ((toastentry = (PgStat_StatToastEntry *) hash_seq_search(&ostat)) != NULL)
+	{
+		fputc('O', fpout);
+		rc = fwrite(toastentry, sizeof(PgStat_StatToastEntry), 1, fpout);
+		(void) rc;				/* we'll check for error with ferror */
+	}
+
 	/*
 	 * No more output to be done. Close the temp file and replace the old
 	 * pgstat.stat with it.  The ferror() check replaces testing for error
@@ -2784,6 +2840,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 				memcpy(dbentry, &dbbuf, sizeof(PgStat_StatDBEntry));
 				dbentry->tables = NULL;
 				dbentry->functions = NULL;
+				dbentry->toastactivity = NULL;
 
 				/*
 				 * In the collector, disregard the timestamp we read from the
@@ -2821,6 +2878,14 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 												 &hash_ctl,
 												 HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
 
+				hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+				hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+				hash_ctl.hcxt = pgStatLocalContext;
+				dbentry->toastactivity = hash_create("Per-database toast information",
+												 PGSTAT_TOAST_HASH_SIZE,
+												 &hash_ctl,
+												 HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
+
 				/*
 				 * If requested, read the data from the database-specific
 				 * file.  Otherwise we just leave the hashtables empty.
@@ -2829,6 +2894,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 					pgstat_read_db_statsfile(dbentry->databaseid,
 											 dbentry->tables,
 											 dbentry->functions,
+											 dbentry->toastactivity,
 											 permanent);
 
 				break;
@@ -2951,13 +3017,15 @@ done:
  * ----------
  */
 static void
-pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 						 bool permanent)
 {
 	PgStat_StatTabEntry *tabentry;
 	PgStat_StatTabEntry tabbuf;
 	PgStat_StatFuncEntry funcbuf;
 	PgStat_StatFuncEntry *funcentry;
+	PgStat_StatToastEntry toastbuf;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpin;
 	int32		format_id;
 	bool		found;
@@ -3071,6 +3139,32 @@ pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
 				memcpy(funcentry, &funcbuf, sizeof(funcbuf));
 				break;
 
+
+				/*
+				 * 'O'	A PgStat_StatToastEntry follows (tOast)
+				 */
+			case 'O':
+				if (fread(&toastbuf, 1, sizeof(PgStat_StatToastEntry),
+						  fpin) != sizeof(PgStat_StatToastEntry))
+				{
+					ereport(pgStatRunningInCollector ? LOG : WARNING,
+							(errmsg("corrupted statistics file \"%s\"",
+									statfile)));
+					goto done;
+				}
+
+				/*
+				 * Skip if TOAST data not wanted.
+				 */
+				if (toasthash == NULL)
+					break;
+
+				toastentry = (PgStat_StatToastEntry *) hash_search(toasthash,
+																 (void *) &toastbuf.t_id,
+																 HASH_ENTER, &found);
+				memcpy(toastentry, &toastbuf, sizeof(toastbuf));
+				break;
+
 				/*
 				 * 'E'	The EOF marker of a complete stats file.
 				 */
@@ -3745,6 +3839,8 @@ pgstat_recv_dropdb(PgStat_MsgDropdb *msg, int len)
 			hash_destroy(dbentry->tables);
 		if (dbentry->functions != NULL)
 			hash_destroy(dbentry->functions);
+		if (dbentry->toastactivity != NULL)
+			hash_destroy(dbentry->toastactivity);
 
 		if (hash_search(pgStatDBHash,
 						(void *) &dbid,
@@ -3781,7 +3877,8 @@ pgstat_recv_resetcounter(PgStat_MsgResetcounter *msg, int len)
 		hash_destroy(dbentry->tables);
 	if (dbentry->functions != NULL)
 		hash_destroy(dbentry->functions);
-
+	if (dbentry->toastactivity != NULL)
+		hash_destroy(dbentry->toastactivity);
 	dbentry->tables = NULL;
 	dbentry->functions = NULL;
 
@@ -4444,6 +4541,60 @@ pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len)
 	}
 }
 
+/* ----------
+ * pgstat_recv_toaststat() -
+ *
+ *	Count what the backend has done.
+ * ----------
+ */
+static void
+pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len)
+{
+	PgStat_ToastEntry *toastmsg = &(msg->m_entry[0]);
+	PgStat_StatDBEntry *dbentry;
+	PgStat_StatToastEntry *toastentry;
+	int			i;
+	bool		found;
+
+	dbentry = pgstat_get_db_entry(msg->m_databaseid, true);
+
+	/*
+	 * Process all TOAST entries in the message.
+	 */
+	for (i = 0; i < msg->m_nentries; i++, toastmsg++)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &(toastmsg->attr),
+														 HASH_ENTER, &found);
+
+		if (!found)
+		{
+			/*
+			 * If it's a new entry, initialize counters to the values
+			 * we just got.
+			 */
+			toastentry->t_numexternalized = toastmsg->t_numexternalized;
+			toastentry->t_numcompressed = toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess = toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_orig = toastmsg->t_size_orig;
+			toastentry->t_size_compressed = toastmsg->t_size_compressed;
+			toastentry->t_comp_time = toastmsg->t_comp_time;
+		}
+		else
+		{
+			/*
+			 * Otherwise add the values to the existing entry.
+			 */
+			toastentry->t_numexternalized += toastmsg->t_numexternalized;
+			toastentry->t_numcompressed += toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess += toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_orig += toastmsg->t_size_orig;
+			toastentry->t_size_compressed += toastmsg->t_size_compressed;
+			toastentry->t_comp_time += toastmsg->t_comp_time;
+		}
+	}
+}
+
 /* ----------
  * pgstat_recv_subscription_drop() -
  *
diff --git a/src/backend/utils/activity/Makefile b/src/backend/utils/activity/Makefile
index 25a967ab7d..229cdaefd3 100644
--- a/src/backend/utils/activity/Makefile
+++ b/src/backend/utils/activity/Makefile
@@ -26,6 +26,7 @@ OBJS = \
 	pgstat_subscription.o \
 	pgstat_wal.o \
 	pgstat_slru.o \
+	pgstat_toast.o \
 	wait_event.o
 
 include $(top_srcdir)/src/backend/common.mk
diff --git a/src/backend/utils/activity/pgstat_toast.c b/src/backend/utils/activity/pgstat_toast.c
new file mode 100644
index 0000000000..b6ba62c302
--- /dev/null
+++ b/src/backend/utils/activity/pgstat_toast.c
@@ -0,0 +1,157 @@
+/* -------------------------------------------------------------------------
+ *
+ * pgstat_toast.c
+ *	  Implementation of TOAST statistics.
+ *
+ * This file contains the implementation of TOAST statistics. It is kept
+ * separate from pgstat.c to enforce the line between the statistics access /
+ * storage implementation and the details about individual types of
+ * statistics.
+ *
+ * Copyright (c) 2001-2022, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/activity/pgstat_toast.c
+ * -------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "utils/pgstat_internal.h"
+#include "utils/timestamp.h"
+
+/*
+ * Indicates if backend has some function stats that it hasn't yet
+ * sent to the collector.
+ */
+bool		have_toast_stats = false;
+
+/*
+ * Backends store per-toast-column info that's waiting to be sent to the collector
+ * in this hash table (indexed by column's PgStat_BackendAttrIdentifier).
+ */
+static HTAB *pgStatToastActions = NULL;
+
+/*
+ * Report TOAST activity
+ * Called by toast_helper functions.
+ */
+void
+pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							instr_time start_time)
+{
+	PgStat_BackendAttrIdentifier toastattr = { relid, attr };
+	PgStat_BackendToastEntry *htabent;
+	instr_time	time_spent;
+	bool		found;
+
+	if (pgStatSock == PGINVALID_SOCKET || !pgstat_track_toast)
+		return;
+
+	INSTR_TIME_SET_CURRENT(time_spent);
+	INSTR_TIME_SUBTRACT(time_spent, start_time);
+
+	if (!pgStatToastActions)
+	{
+		/* First time through - initialize toast stat table */
+		HASHCTL		hash_ctl;
+
+		hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+		hash_ctl.entrysize = sizeof(PgStat_BackendToastEntry);
+		pgStatToastActions = hash_create("TOAST stat entries",
+									  PGSTAT_TOAST_HASH_SIZE,
+									  &hash_ctl,
+									  HASH_ELEM | HASH_BLOBS);
+	}
+
+	/* Get the stats entry for this TOAST attribute, create if necessary */
+	htabent = hash_search(pgStatToastActions, &toastattr,
+						  HASH_ENTER, &found);
+	if (!found)
+	{
+		MemSet(&htabent->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	/* update counters */
+	if (externalized)
+	{
+		htabent->t_counts.t_numexternalized++;
+	}
+	if (compressed)
+	{
+		htabent->t_counts.t_numcompressed++;
+		htabent->t_counts.t_size_orig+=old_size;
+		if (new_size)
+		{
+			htabent->t_counts.t_numcompressionsuccess++;
+			htabent->t_counts.t_size_compressed+=new_size;
+		}
+	}
+	/* record time spent */
+	INSTR_TIME_ADD(htabent->t_counts.t_comp_time, time_spent);
+
+	/* indicate that we have something to send */
+	have_toast_stats = true;
+}
+
+/*
+ * Subroutine for pgstat_report_stat: populate and send a toast stat message
+ */
+void
+pgstat_send_toaststats(void)
+{
+	static const PgStat_ToastCounts all_zeroes;
+
+	PgStat_MsgToaststat msg;
+	PgStat_BackendToastEntry *entry;
+	HASH_SEQ_STATUS tstat;
+
+	if (pgStatToastActions == NULL)
+		return;
+
+	pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_TOASTSTAT);
+	msg.m_databaseid = MyDatabaseId;
+	msg.m_nentries = 0;
+
+	hash_seq_init(&tstat, pgStatToastActions);
+	while ((entry = (PgStat_BackendToastEntry *) hash_seq_search(&tstat)) != NULL)
+	{
+		PgStat_ToastEntry *m_ent;
+
+		/* Skip it if no counts accumulated since last time */
+		if (memcmp(&entry->t_counts, &all_zeroes,
+				   sizeof(PgStat_ToastCounts)) == 0)
+			continue;
+
+		/* need to convert format of time accumulators */
+		m_ent = &msg.m_entry[msg.m_nentries];
+		m_ent->attr = entry->attr;
+		m_ent->t_numexternalized = entry->t_counts.t_numexternalized;
+		m_ent->t_numcompressed = entry->t_counts.t_numcompressed;
+		m_ent->t_numcompressionsuccess = entry->t_counts.t_numcompressionsuccess;
+		m_ent->t_size_orig = entry->t_counts.t_size_orig;
+		m_ent->t_size_compressed = entry->t_counts.t_size_compressed;
+		m_ent->t_comp_time = INSTR_TIME_GET_MICROSEC(entry->t_counts.t_comp_time);
+
+		if (++msg.m_nentries >= PGSTAT_NUM_TOASTENTRIES)
+		{
+			pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+						msg.m_nentries * sizeof(PgStat_ToastEntry));
+			msg.m_nentries = 0;
+		}
+
+		/* reset the entry's counts */
+		MemSet(&entry->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	if (msg.m_nentries > 0)
+		pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+					msg.m_nentries * sizeof(PgStat_ToastEntry));
+
+	have_toast_stats = false;
+}
+
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index ce84525d40..a1f74c74ff 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -410,6 +410,78 @@ pg_stat_get_function_self_time(PG_FUNCTION_ARGS)
 	PG_RETURN_FLOAT8(((double) funcentry->f_self_time) / 1000.0);
 }
 
+Datum
+pg_stat_get_toast_externalizations(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numexternalized);
+}
+
+Datum
+pg_stat_get_toast_compressions(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressed);
+}
+
+Datum
+pg_stat_get_toast_compressionsuccesses(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressionsuccess);
+}
+
+Datum
+pg_stat_get_toast_originalsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_orig);
+}
+
+Datum
+pg_stat_get_toast_compressedsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_compressed);
+}
+
+Datum
+pg_stat_get_toast_total_time(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_comp_time);
+}
+
 Datum
 pg_stat_get_backend_idset(PG_FUNCTION_ARGS)
 {
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 9e8ab1420d..339d2553d4 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -1557,6 +1557,15 @@ static struct config_bool ConfigureNamesBool[] =
 		true,
 		NULL, NULL, NULL
 	},
+	{
+		{"track_toast", PGC_SUSET, STATS_COLLECTOR,
+			gettext_noop("Collects statistics on TOAST activity."),
+			NULL
+		},
+		&pgstat_track_toast,
+		false,
+		NULL, NULL, NULL
+	},
 	{
 		{"track_io_timing", PGC_SUSET, STATS_COLLECTOR,
 			gettext_noop("Collects timing statistics for database I/O activity."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 93d221a37b..4c3b7ae29b 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -613,6 +613,7 @@
 #track_io_timing = off
 #track_wal_io_timing = off
 #track_functions = none			# none, pl, all
+#track_toast = off
 #stats_temp_directory = 'pg_stat_tmp'
 
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 25304430f4..6d7ba55293 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5673,6 +5673,31 @@
   proparallel => 'r', prorettype => 'float8', proargtypes => 'oid',
   prosrc => 'pg_stat_get_function_self_time' },
 
+{ oid => '9700', descr => 'statistics: number of TOAST externalizations',
+  proname => 'pg_stat_get_toast_externalizations', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_externalizations' },
+{ oid => '9701', descr => 'statistics: number of TOAST compressions',
+  proname => 'pg_stat_get_toast_compressions', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressions' },
+  { oid => '9702', descr => 'statistics: number of successful TOAST compressions',
+  proname => 'pg_stat_get_toast_compressionsuccesses', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressionsuccesses' },
+{ oid => '9703', descr => 'statistics: total original size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_originalsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_originalsizesum' },
+{ oid => '9704', descr => 'statistics: total compressed size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_compressedsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressedsizesum' },
+{ oid => '9705', descr => 'statistics: total time spend TOASTing data',
+  proname => 'pg_stat_get_toast_total_time', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_total_time' },
+
 { oid => '3037',
   descr => 'statistics: number of scans done for table/index in current transaction',
   proname => 'pg_stat_get_xact_numscans', provolatile => 'v',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 534d595ca0..7c8191aefe 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -33,7 +33,6 @@
 /* Default directory to store temporary statistics data in */
 #define PG_STAT_TMP_DIR		"pg_stat_tmp"
 
-
 /* Values for track_functions GUC variable --- order is significant! */
 typedef enum TrackFunctionsLevel
 {
@@ -252,6 +251,7 @@ typedef enum StatMsgType
 	PGSTAT_MTYPE_DISCONNECT,
 	PGSTAT_MTYPE_SUBSCRIPTIONDROP,
 	PGSTAT_MTYPE_SUBSCRIPTIONERROR,
+	PGSTAT_MTYPE_TOASTSTAT,
 } StatMsgType;
 
 /* ----------
@@ -726,6 +726,80 @@ typedef struct PgStat_MsgDisconnect
 	SessionEndType m_cause;
 } PgStat_MsgDisconnect;
 
+/* ----------
+ * PgStat_BackendAttrIdentifier	Identifier for a single attribute/column (OID + attr)
+ * Used as a hashable identifier for (e.g.) TOAST columns
+ * ----------
+ */
+typedef struct PgStat_BackendAttrIdentifier
+{
+	Oid			relid;
+	int			attr;
+} PgStat_BackendAttrIdentifier;
+
+/* ----------
+ * PgStat_ToastCounts	The actual per-TOAST counts kept by a backend
+ *
+ * This struct should contain only actual event counters, because we memcmp
+ * it against zeroes to detect whether there are any counts to transmit.
+ *
+ * Note that the time counters are in instr_time format here.  We convert to
+ * microseconds in PgStat_Counter format when transmitting to the collector.
+ * ----------
+ */
+typedef struct PgStat_ToastCounts
+{
+	PgStat_Counter	t_numexternalized;
+	PgStat_Counter	t_numcompressed;
+	PgStat_Counter	t_numcompressionsuccess;
+	uint64		t_size_orig;
+	uint64		t_size_compressed;
+	instr_time	t_comp_time;
+} PgStat_ToastCounts;
+
+/* ----------
+ * PgStat_BackendToastEntry	Entry in backend's per-toast-attr hash table
+ * ----------
+ */
+typedef struct PgStat_BackendToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_ToastCounts 		t_counts;
+} PgStat_BackendToastEntry;
+
+/* ----------
+ * PgStat_ToastEntry			Per-TOAST-column info in a MsgToaststat
+ * ----------
+ */
+typedef struct PgStat_ToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_Counter 			t_numexternalized;
+	PgStat_Counter 			t_numcompressed;
+	PgStat_Counter 			t_numcompressionsuccess;
+	uint64		   		t_size_orig;
+	uint64		   		t_size_compressed;
+	PgStat_Counter			t_comp_time;	/* time in microseconds */
+} PgStat_ToastEntry;
+
+/* ----------
+ * PgStat_MsgToaststat			Sent by the backend to report function
+ *								usage statistics.
+ * ----------
+ */
+#define PGSTAT_NUM_TOASTENTRIES	\
+	((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - sizeof(int))  \
+	 / sizeof(PgStat_ToastEntry))
+
+typedef struct PgStat_MsgToaststat
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+	int			m_nentries;
+	PgStat_ToastEntry m_entry[PGSTAT_NUM_TOASTENTRIES];
+} PgStat_MsgToaststat;
+
+
 /* ----------
  * PgStat_Msg					Union over all possible messages.
  * ----------
@@ -754,6 +828,7 @@ typedef union PgStat_Msg
 	PgStat_MsgSLRU msg_slru;
 	PgStat_MsgFuncstat msg_funcstat;
 	PgStat_MsgFuncpurge msg_funcpurge;
+	PgStat_MsgToaststat msg_toaststat;
 	PgStat_MsgRecoveryConflict msg_recoveryconflict;
 	PgStat_MsgDeadlock msg_deadlock;
 	PgStat_MsgTempFile msg_tempfile;
@@ -774,7 +849,7 @@ typedef union PgStat_Msg
  * ------------------------------------------------------------
  */
 
-#define PGSTAT_FILE_FORMAT_ID	0x01A5BCA6
+#define PGSTAT_FILE_FORMAT_ID	0x01A5BCA7
 
 /*
  * Archiver statistics kept in the stats collector
@@ -864,6 +939,7 @@ typedef struct PgStat_StatDBEntry
 	 */
 	HTAB	   *tables;
 	HTAB	   *functions;
+	HTAB	   *toastactivity;
 } PgStat_StatDBEntry;
 
 /* ----------
@@ -936,6 +1012,22 @@ typedef struct PgStat_StatSubEntry
 } PgStat_StatSubEntry;
 
 /* ----------
+ * PgStat_StatToastEntry			The collector's data per TOAST attribute
+ * ----------
+ */
+typedef struct PgStat_StatToastEntry
+{
+	PgStat_BackendAttrIdentifier t_id;
+	PgStat_Counter t_numexternalized;
+	PgStat_Counter t_numcompressed;
+	PgStat_Counter t_numcompressionsuccess;
+	uint64		   t_size_orig;
+	uint64		   t_size_compressed;
+	PgStat_Counter t_comp_time;	/* time in microseconds */
+} PgStat_StatToastEntry;
+
+
+/*
  * PgStat_StatTabEntry			The collector's data per table (or index)
  * ----------
  */
@@ -1027,6 +1119,7 @@ extern PgStat_BgWriterStats *pgstat_fetch_stat_bgwriter(void);
 extern PgStat_CheckpointerStats *pgstat_fetch_stat_checkpointer(void);
 extern PgStat_StatDBEntry *pgstat_fetch_stat_dbentry(Oid dbid);
 extern PgStat_StatFuncEntry *pgstat_fetch_stat_funcentry(Oid funcid);
+extern PgStat_StatToastEntry *pgstat_fetch_stat_toastentry(Oid rel_id, int attr);
 extern PgStat_GlobalStats *pgstat_fetch_global(void);
 extern PgStat_StatReplSlotEntry *pgstat_fetch_replslot(NameData slotname);
 extern PgStat_StatSubEntry *pgstat_fetch_stat_subscription(Oid subid);
@@ -1090,6 +1183,7 @@ extern void pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu,
 extern PgStat_BackendFunctionEntry *find_funcstat_entry(Oid func_id);
 
 
+
 /*
  * Functions in pgstat_relation.c
  */
@@ -1199,6 +1293,17 @@ extern void pgstat_report_subscription_drop(Oid subid);
 
 extern void pgstat_send_wal(bool force);
 
+/*
+ * Functions in pgstat_toast.c
+ */
+
+extern void pgstat_send_toaststats(void);
+extern void pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							instr_time start_time);
 
 /*
  * Variables in pgstat.c
@@ -1207,6 +1312,7 @@ extern void pgstat_send_wal(bool force);
 /* GUC parameters */
 extern PGDLLIMPORT bool pgstat_track_counts;
 extern PGDLLIMPORT int pgstat_track_functions;
+extern PGDLLIMPORT bool pgstat_track_toast;
 extern char *pgstat_stat_directory;
 extern char *pgstat_stat_tmpname;
 extern char *pgstat_stat_filename;
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index abbb4f8d96..44b0aeb7af 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -27,6 +27,7 @@
 #define PGSTAT_DB_HASH_SIZE		16
 #define PGSTAT_TAB_HASH_SIZE	512
 #define PGSTAT_FUNCTION_HASH_SIZE	512
+#define PGSTAT_TOAST_HASH_SIZE	64
 #define PGSTAT_SUBSCRIPTION_HASH_SIZE	32
 #define PGSTAT_REPLSLOT_HASH_SIZE	32
 
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index 423b9b99fb..91358a5b62 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -2128,6 +2128,23 @@ pg_stat_sys_tables| SELECT pg_stat_all_tables.relid,
     pg_stat_all_tables.autoanalyze_count
    FROM pg_stat_all_tables
   WHERE ((pg_stat_all_tables.schemaname = ANY (ARRAY['pg_catalog'::name, 'information_schema'::name])) OR (pg_stat_all_tables.schemaname ~ '^pg_toast'::text));
+pg_stat_toast| SELECT n.nspname AS schemaname,
+    a.attrelid AS reloid,
+    a.attnum,
+    c.relname,
+    a.attname,
+    a.attstorage AS storagemethod,
+    pg_stat_get_toast_externalizations(a.attrelid, (a.attnum)::integer) AS externalized,
+    a.attcompression AS compressmethod,
+    pg_stat_get_toast_compressions(a.attrelid, (a.attnum)::integer) AS compressattempts,
+    pg_stat_get_toast_compressionsuccesses(a.attrelid, (a.attnum)::integer) AS compresssuccesses,
+    pg_stat_get_toast_compressedsizesum(a.attrelid, (a.attnum)::integer) AS compressedsize,
+    pg_stat_get_toast_originalsizesum(a.attrelid, (a.attnum)::integer) AS originalsize,
+    pg_stat_get_toast_total_time(a.attrelid, (a.attnum)::integer) AS total_time
+   FROM ((pg_attribute a
+     JOIN pg_class c ON ((c.oid = a.attrelid)))
+     LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace)))
+  WHERE (pg_stat_get_toast_externalizations(a.attrelid, (a.attnum)::integer) IS NOT NULL);
 pg_stat_user_functions| SELECT p.oid AS funcid,
     n.nspname AS schemaname,
     p.proname AS funcname,
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 06a1d2f229..b9514e1f34 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -11,6 +11,32 @@ SHOW track_counts;  -- must be on
  on
 (1 row)
 
+-- prepare and fill the pg_stat_toast table now:
+SHOW track_toast;
+ track_toast 
+-------------
+ off
+(1 row)
+
+SET track_toast TO on;
+SHOW track_toast;
+ track_toast 
+-------------
+ on
+(1 row)
+
+TABLE pg_stat_toast; -- view exists
+ schemaname | reloid | attnum | relname | attname | storagemethod | externalized | compressmethod | compressattempts | compresssuccesses | compressedsize | originalsize | total_time 
+------------+--------+--------+---------+---------+---------------+--------------+----------------+------------------+-------------------+----------------+--------------+------------
+(0 rows)
+
+CREATE TABLE toast_test (cola TEXT, colb TEXT, colc TEXT , cold TEXT);
+ALTER TABLE toast_test ALTER colb SET STORAGE EXTERNAL;
+ALTER TABLE toast_test ALTER colc SET STORAGE MAIN;
+ALTER TABLE toast_test ALTER cold SET STORAGE PLAIN;
+INSERT INTO toast_test VALUES (repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100) );
+-- make sure we don't interfere with the other tests:
+SET track_toast TO off;
 -- ensure that both seqscan and indexscan plans are allowed
 SET enable_seqscan TO on;
 SET enable_indexscan TO on;
@@ -255,6 +281,42 @@ SELECT pg_stat_get_tuples_hot_updated('brin_hot'::regclass::oid);
 
 DROP TABLE brin_hot;
 DROP FUNCTION wait_for_hot_stats();
+-- now check that the track_toast stuff worked:
+SELECT attname
+	,storagemethod
+	,externalized
+	,compressmethod
+	,compressattempts
+	,compresssuccesses
+	,compressedsize < originalsize AS compression_works
+	, total_time > 0 AS takes_time
+FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY attname;
+ attname | storagemethod | externalized | compressmethod | compressattempts | compresssuccesses | compression_works | takes_time 
+---------+---------------+--------------+----------------+------------------+-------------------+-------------------+------------
+ cola    | x             |            1 |                |                1 |                 1 | t                 | t
+ colb    | e             |            1 |                |                0 |                 0 | f                 | t
+ colc    | m             |            0 |                |                1 |                 1 | t                 | t
+(3 rows)
+
+SELECT compressattempts=0 AS external_doesnt_compress FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'e';
+ external_doesnt_compress 
+--------------------------
+ t
+(1 row)
+
+SELECT externalized=0 AS main_doesnt_externalize FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'm';
+ main_doesnt_externalize 
+-------------------------
+ t
+(1 row)
+
+DROP TABLE toast_test;
+SELECT count(*) FROM pg_stat_toast WHERE relname = 'toast_test';
+ count 
+-------
+     0
+(1 row)
+
 -- ensure that stats accessors handle NULL input correctly
 SELECT pg_stat_get_replication_slot(NULL);
  pg_stat_get_replication_slot 
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index ae1ec173e3..b30de2fa7a 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -8,6 +8,20 @@
 -- conditio sine qua non
 SHOW track_counts;  -- must be on
 
+-- prepare and fill the pg_stat_toast table now:
+SHOW track_toast;
+SET track_toast TO on;
+SHOW track_toast;
+TABLE pg_stat_toast; -- view exists
+
+CREATE TABLE toast_test (cola TEXT, colb TEXT, colc TEXT , cold TEXT);
+ALTER TABLE toast_test ALTER colb SET STORAGE EXTERNAL;
+ALTER TABLE toast_test ALTER colc SET STORAGE MAIN;
+ALTER TABLE toast_test ALTER cold SET STORAGE PLAIN;
+INSERT INTO toast_test VALUES (repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100) );
+-- make sure we don't interfere with the other tests:
+SET track_toast TO off;
+
 -- ensure that both seqscan and indexscan plans are allowed
 SET enable_seqscan TO on;
 SET enable_indexscan TO on;
@@ -228,6 +242,20 @@ SELECT pg_stat_get_tuples_hot_updated('brin_hot'::regclass::oid);
 DROP TABLE brin_hot;
 DROP FUNCTION wait_for_hot_stats();
 
+-- now check that the track_toast stuff worked:
+SELECT attname
+	,storagemethod
+	,externalized
+	,compressmethod
+	,compressattempts
+	,compresssuccesses
+	,compressedsize < originalsize AS compression_works
+	, total_time > 0 AS takes_time
+FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY attname;
+SELECT compressattempts=0 AS external_doesnt_compress FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'e';
+SELECT externalized=0 AS main_doesnt_externalize FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'm';
+DROP TABLE toast_test;
+SELECT count(*) FROM pg_stat_toast WHERE relname = 'toast_test';
 
 -- ensure that stats accessors handle NULL input correctly
 SELECT pg_stat_get_replication_slot(NULL);

 doc/src/sgml/config.sgml                      |  26 ++++
 doc/src/sgml/monitoring.sgml                  | 163 ++++++++++++++++++++++++++
 doc/src/sgml/storage.sgml                     |  12 +-
 src/backend/access/table/toast_helper.c       |  40 +++++++
 src/backend/catalog/system_views.sql          |  20 ++++
 src/backend/postmaster/pgstat.c               | 161 ++++++++++++++++++++++++-
 src/backend/utils/activity/Makefile           |   1 +
 src/backend/utils/activity/pgstat_toast.c     | 157 +++++++++++++++++++++++++
 src/backend/utils/adt/pgstatfuncs.c           |  72 ++++++++++++
 src/backend/utils/misc/guc.c                  |   9 ++
 src/backend/utils/misc/postgresql.conf.sample |   1 +
 src/include/catalog/pg_proc.dat               |  25 ++++
 src/include/pgstat.h                          | 110 ++++++++++++++++-
 src/include/utils/pgstat_internal.h           |   1 +
 src/test/regress/expected/rules.out           |  17 +++
 src/test/regress/expected/stats.out           |  62 ++++++++++
 src/test/regress/sql/stats.sql                |  28 +++++
 17 files changed, 897 insertions(+), 8 deletions(-)

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 43e4ade83e..e6f0768472 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -7935,6 +7935,32 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv;
       </listitem>
      </varlistentry>
 
+     <varlistentry id="guc-track-toast" xreflabel="track_toast">
+      <term><varname>track_toast</varname> (<type>boolean</type>)
+      <indexterm>
+       <primary><varname>track_toast</varname> configuration parameter</primary>
+      </indexterm>
+      </term>
+      <listitem>
+       <para>
+        Enables tracking of <link linkend="storage-toast">TOAST</link> activities.
+        Compressions and externalizations are tracked.
+        The default is <literal>off</literal>.
+        Only superusers can change this setting.
+       </para>
+
+       <note>
+        <para>
+        Be aware that this feature, depending on the amount of TOASTable columns in
+        your databases, may significantly increase the size of the statistics files
+        and the workload of the statistics collector. It is recommended to only
+        temporarily activate this to assess the right compression and storage method
+        for a column.
+        </para>
+       </note>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="guc-stats-temp-directory" xreflabel="stats_temp_directory">
       <term><varname>stats_temp_directory</varname> (<type>string</type>)
       <indexterm>
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 3b9172f65b..cd0a5bea35 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -610,6 +610,17 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
       yet included in <structname>pg_stat_user_functions</structname>).</entry>
      </row>
 
+     <row>
+      <entry><structname>pg_stat_toast</structname><indexterm><primary>pg_stat_toast</primary></indexterm></entry>
+      <entry>
+       One row for each column that has ever been TOASTed (compressed and/or externalized).
+       Showing the number of externalizations, compression attempts / successes, compressed and
+       uncompressed sizes etc.
+       <link linkend="monitoring-pg-stat-toast-view">
+       <structname>pg_stat_toast</structname></link> for details.
+      </entry>
+     </row>
+
      <row>
       <entry><structname>pg_stat_slru</structname><indexterm><primary>pg_stat_slru</primary></indexterm></entry>
       <entry>One row per SLRU, showing statistics of operations. See
@@ -4946,6 +4957,158 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
 
  </sect2>
 
+ <sect2 id="monitoring-pg-stat-toast-view">
+  <title><structname>pg_stat_toast</structname></title>
+
+  <indexterm>
+   <primary>pg_stat_toast</primary>
+  </indexterm>
+
+  <para>
+   The <structname>pg_stat_toast</structname> view will contain
+   one row for each column of variable size that has been TOASTed since 
+   the last statistics reset. The <xref linkend="guc-track-toast"/> parameter
+   controls whether TOAST activities are tracked or not.
+  </para>
+
+  <table id="pg-stat-toast-view" xreflabel="pg_stat_toast">
+   <title><structname>pg_stat_toast</structname> View</title>
+   <tgroup cols="1">
+    <thead>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       Column Type
+      </para>
+      <para>
+       Description
+      </para></entry>
+     </row>
+    </thead>
+
+    <tbody>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>schemaname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the schema the relation is in
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>reloid</structfield> <type>oid</type>
+      </para>
+      <para>
+       OID of the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>attnum</structfield> <type>int</type>
+      </para>
+      <para>
+       Attribute (column) number in the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>relname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>attname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the attribute (column)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>storagemethod</structfield> <type>char</type>
+      </para>
+      <para>
+       Storage method of the attribute
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>externalized</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times this attribute was externalized (pushed to TOAST relation)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressmethod</structfield> <type>char</type>
+      </para>
+      <para>
+       Current compression method of the attribute (empty means default)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressattempts</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times compression of this attribute was attempted
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compresssuccesses</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times compression of this attribute was successful
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressedsize</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total size of all compressed datums
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>originalsize</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total size of all compressed datums before compression
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>total_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Total time spent TOASTing this attribute, in microseconds.
+      </para></entry>
+     </row>
+
+    </tbody>
+   </tgroup>
+  </table>
+
+ </sect2>
+
  <sect2 id="monitoring-pg-stat-slru-view">
   <title><structname>pg_stat_slru</structname></title>
 
diff --git a/doc/src/sgml/storage.sgml b/doc/src/sgml/storage.sgml
index f4b9f66589..d0e165d5f1 100644
--- a/doc/src/sgml/storage.sgml
+++ b/doc/src/sgml/storage.sgml
@@ -517,6 +517,15 @@ pages). There was no run time difference compared to an un-<acronym>TOAST</acron
 comparison table, in which all the HTML pages were cut down to 7 kB to fit.
 </para>
 
+<para>
+When you enable <xref linkend="guc-track-toast"/>, the system view
+<link linkend="monitoring-pg-stat-toast-view"><structname>pg_stat_toast</structname>
+</link> provides details on the number and effect of compression attempts,
+number of externalizations and some more useful information that enables you
+to decide if a different storage method and/or compression method would suite a
+column better.
+</para>
+
 </sect2>
 
 <sect2 id="storage-toast-inmemory">
@@ -1069,7 +1078,8 @@ data. Empty in ordinary tables.</entry>
   <type>struct varlena</type>, which includes the total length of the stored
   value and some flag bits.  Depending on the flags, the data can be either
   inline or in a <acronym>TOAST</acronym> table;
-  it might be compressed, too (see <xref linkend="storage-toast"/>).
+  it might be compressed, too (see <xref linkend="storage-toast"/> and 
+  <xref linkend="monitoring-pg-stat-toast-view"/>).
 
  </para>
  </sect2>
diff --git a/src/backend/access/table/toast_helper.c b/src/backend/access/table/toast_helper.c
index 0cc5a30f9b..98d10a0670 100644
--- a/src/backend/access/table/toast_helper.c
+++ b/src/backend/access/table/toast_helper.c
@@ -19,7 +19,9 @@
 #include "access/toast_helper.h"
 #include "access/toast_internals.h"
 #include "catalog/pg_type_d.h"
+#include "pgstat.h"
 
+PGDLLIMPORT bool pgstat_track_toast;
 
 /*
  * Prepare to TOAST a tuple.
@@ -229,7 +231,12 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 	Datum	   *value = &ttc->ttc_values[attribute];
 	Datum		new_value;
 	ToastAttrInfo *attr = &ttc->ttc_attr[attribute];
+	instr_time	start_time;
 
+	if (pgstat_track_toast)
+	{
+		INSTR_TIME_SET_CURRENT(start_time);
+	}
 	new_value = toast_compress_datum(*value, attr->tai_compression);
 
 	if (DatumGetPointer(new_value) != NULL)
@@ -239,6 +246,15 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 			pfree(DatumGetPointer(*value));
 		*value = new_value;
 		attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
+		if (pgstat_track_toast)
+		{
+			pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							attr->tai_size,
+							VARSIZE(DatumGetPointer(*value)),
+							start_time);
+		}
 		attr->tai_size = VARSIZE(DatumGetPointer(*value));
 		ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
 	}
@@ -246,6 +262,15 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 	{
 		/* incompressible, ignore on subsequent compression passes */
 		attr->tai_colflags |= TOASTCOL_INCOMPRESSIBLE;
+		if (pgstat_track_toast)
+		{
+			pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							0,
+							0,
+							start_time);
+		}
 	}
 }
 
@@ -258,6 +283,12 @@ toast_tuple_externalize(ToastTupleContext *ttc, int attribute, int options)
 	Datum	   *value = &ttc->ttc_values[attribute];
 	Datum		old_value = *value;
 	ToastAttrInfo *attr = &ttc->ttc_attr[attribute];
+	instr_time	start_time;
+
+	if (pgstat_track_toast)
+	{
+		INSTR_TIME_SET_CURRENT(start_time);
+	}
 
 	attr->tai_colflags |= TOASTCOL_IGNORE;
 	*value = toast_save_datum(ttc->ttc_rel, old_value, attr->tai_oldexternal,
@@ -266,6 +297,15 @@ toast_tuple_externalize(ToastTupleContext *ttc, int attribute, int options)
 		pfree(DatumGetPointer(old_value));
 	attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
 	ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
+	if (pgstat_track_toast)
+	{
+		pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							true,
+							false,
+							0,
+							0,
+							start_time);
+}
 }
 
 /*
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 9eaa51df29..e9cce5c51a 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -1066,6 +1066,26 @@ CREATE VIEW pg_stat_user_functions AS
     WHERE P.prolang != 12  -- fast check to eliminate built-in functions
           AND pg_stat_get_function_calls(P.oid) IS NOT NULL;
 
+
+CREATE OR REPLACE VIEW pg_stat_toast AS
+ SELECT
+    n.nspname AS schemaname,
+    a.attrelid AS reloid,
+    a.attnum AS attnum,
+    c.relname AS relname,
+    a.attname AS attname,
+    attstorage AS storagemethod,
+    pg_stat_get_toast_externalizations(a.attrelid,a.attnum) AS externalized,
+    attcompression AS compressmethod,
+    pg_stat_get_toast_compressions(a.attrelid,a.attnum) AS compressattempts,
+    pg_stat_get_toast_compressionsuccesses(a.attrelid,a.attnum) AS compresssuccesses,
+    pg_stat_get_toast_compressedsizesum(a.attrelid,a.attnum) AS compressedsize,
+    pg_stat_get_toast_originalsizesum(a.attrelid,a.attnum) AS originalsize,
+    pg_stat_get_toast_total_time(a.attrelid,a.attnum) AS total_time
+   FROM pg_attribute a
+   JOIN pg_class c ON c.oid = a.attrelid
+   LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
+  WHERE pg_stat_get_toast_externalizations(a.attrelid,a.attnum) IS NOT NULL;
 CREATE VIEW pg_stat_xact_user_functions AS
     SELECT
             P.oid AS funcid,
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index c10311e036..c4cf0a33fc 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -116,7 +116,7 @@ static void pgstat_reset_subscription(PgStat_StatSubEntry *subentry, TimestampTz
 static void pgstat_write_statsfiles(bool permanent, bool allDbs);
 static void pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent);
 static HTAB *pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep);
-static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 									 bool permanent);
 static void backend_read_statsfile(void);
 
@@ -159,6 +159,7 @@ static void pgstat_recv_replslot(PgStat_MsgReplSlot *msg, int len);
 static void pgstat_recv_tempfile(PgStat_MsgTempFile *msg, int len);
 static void pgstat_recv_subscription_drop(PgStat_MsgSubscriptionDrop *msg, int len);
 static void pgstat_recv_subscription_error(PgStat_MsgSubscriptionError *msg, int len);
+static void pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len);
 
 
 /* ----------
@@ -168,7 +169,6 @@ static void pgstat_recv_subscription_error(PgStat_MsgSubscriptionError *msg, int
 
 bool		pgstat_track_counts = false;
 
-
 /* ----------
  * Built from GUC parameter
  * ----------
@@ -972,6 +972,9 @@ pgstat_report_stat(bool disconnect)
 	/* Now, send function statistics */
 	pgstat_send_funcstats();
 
+	/* Now, send TOAST statistics */
+	pgstat_send_toaststats();
+
 	/* Send WAL statistics */
 	pgstat_send_wal(true);
 
@@ -1494,6 +1497,35 @@ pgstat_fetch_stat_funcentry(Oid func_id)
 	return funcentry;
 }
 
+/* ----------
+ * pgstat_fetch_stat_toastentry() -
+ *
+ *	Support function for the SQL-callable pgstat* functions. Returns
+ *	the collected statistics for one TOAST attribute or NULL.
+ * ----------
+ */
+PgStat_StatToastEntry *
+pgstat_fetch_stat_toastentry(Oid rel_id, int attr)
+{
+	PgStat_StatDBEntry *dbentry;
+	PgStat_BackendAttrIdentifier toast_id = { rel_id, attr };
+	PgStat_StatToastEntry *toastentry = NULL;
+
+	/* load the stats file if needed */
+	backend_read_statsfile();
+
+	/* Lookup our database, then find the requested TOAST activity stats.  */
+	dbentry = pgstat_fetch_stat_dbentry(MyDatabaseId);
+	if (dbentry != NULL && dbentry->toastactivity != NULL)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &toast_id,
+														 HASH_FIND, NULL);
+	}
+
+	return toastentry;
+}
+
 /*
  * ---------
  * pgstat_fetch_stat_archiver() -
@@ -1914,6 +1946,10 @@ PgstatCollectorMain(int argc, char *argv[])
 					pgstat_recv_funcpurge(&msg.msg_funcpurge, len);
 					break;
 
+				case PGSTAT_MTYPE_TOASTSTAT:
+					pgstat_recv_toaststat(&msg.msg_toaststat, len);
+					break;
+
 				case PGSTAT_MTYPE_RECOVERYCONFLICT:
 					pgstat_recv_recoveryconflict(&msg.msg_recoveryconflict,
 												 len);
@@ -2050,6 +2086,13 @@ reset_dbentry_counters(PgStat_StatDBEntry *dbentry)
 									 PGSTAT_FUNCTION_HASH_SIZE,
 									 &hash_ctl,
 									 HASH_ELEM | HASH_BLOBS);
+
+	hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+	hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+	dbentry->toastactivity = hash_create("Per-database TOAST",
+									 PGSTAT_TOAST_HASH_SIZE,
+									 &hash_ctl,
+									 HASH_ELEM | HASH_BLOBS);
 }
 
 /*
@@ -2359,7 +2402,7 @@ pgstat_write_statsfiles(bool permanent, bool allDbs)
 	while ((dbentry = (PgStat_StatDBEntry *) hash_seq_search(&hstat)) != NULL)
 	{
 		/*
-		 * Write out the table and function stats for this DB into the
+		 * Write out the table, function and TOAST stats for this DB into the
 		 * appropriate per-DB stat file, if required.
 		 */
 		if (allDbs || pgstat_db_requested(dbentry->databaseid))
@@ -2490,8 +2533,10 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 {
 	HASH_SEQ_STATUS tstat;
 	HASH_SEQ_STATUS fstat;
+	HASH_SEQ_STATUS ostat;
 	PgStat_StatTabEntry *tabentry;
 	PgStat_StatFuncEntry *funcentry;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpout;
 	int32		format_id;
 	Oid			dbid = dbentry->databaseid;
@@ -2546,6 +2591,17 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 		(void) rc;				/* we'll check for error with ferror */
 	}
 
+	/*
+	 * Walk through the database's TOAST stats table.
+	 */
+	hash_seq_init(&ostat, dbentry->toastactivity);
+	while ((toastentry = (PgStat_StatToastEntry *) hash_seq_search(&ostat)) != NULL)
+	{
+		fputc('O', fpout);
+		rc = fwrite(toastentry, sizeof(PgStat_StatToastEntry), 1, fpout);
+		(void) rc;				/* we'll check for error with ferror */
+	}
+
 	/*
 	 * No more output to be done. Close the temp file and replace the old
 	 * pgstat.stat with it.  The ferror() check replaces testing for error
@@ -2784,6 +2840,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 				memcpy(dbentry, &dbbuf, sizeof(PgStat_StatDBEntry));
 				dbentry->tables = NULL;
 				dbentry->functions = NULL;
+				dbentry->toastactivity = NULL;
 
 				/*
 				 * In the collector, disregard the timestamp we read from the
@@ -2821,6 +2878,14 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 												 &hash_ctl,
 												 HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
 
+				hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+				hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+				hash_ctl.hcxt = pgStatLocalContext;
+				dbentry->toastactivity = hash_create("Per-database toast information",
+												 PGSTAT_TOAST_HASH_SIZE,
+												 &hash_ctl,
+												 HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
+
 				/*
 				 * If requested, read the data from the database-specific
 				 * file.  Otherwise we just leave the hashtables empty.
@@ -2829,6 +2894,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 					pgstat_read_db_statsfile(dbentry->databaseid,
 											 dbentry->tables,
 											 dbentry->functions,
+											 dbentry->toastactivity,
 											 permanent);
 
 				break;
@@ -2951,13 +3017,15 @@ done:
  * ----------
  */
 static void
-pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 						 bool permanent)
 {
 	PgStat_StatTabEntry *tabentry;
 	PgStat_StatTabEntry tabbuf;
 	PgStat_StatFuncEntry funcbuf;
 	PgStat_StatFuncEntry *funcentry;
+	PgStat_StatToastEntry toastbuf;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpin;
 	int32		format_id;
 	bool		found;
@@ -3071,6 +3139,32 @@ pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
 				memcpy(funcentry, &funcbuf, sizeof(funcbuf));
 				break;
 
+
+				/*
+				 * 'O'	A PgStat_StatToastEntry follows (tOast)
+				 */
+			case 'O':
+				if (fread(&toastbuf, 1, sizeof(PgStat_StatToastEntry),
+						  fpin) != sizeof(PgStat_StatToastEntry))
+				{
+					ereport(pgStatRunningInCollector ? LOG : WARNING,
+							(errmsg("corrupted statistics file \"%s\"",
+									statfile)));
+					goto done;
+				}
+
+				/*
+				 * Skip if TOAST data not wanted.
+				 */
+				if (toasthash == NULL)
+					break;
+
+				toastentry = (PgStat_StatToastEntry *) hash_search(toasthash,
+																 (void *) &toastbuf.t_id,
+																 HASH_ENTER, &found);
+				memcpy(toastentry, &toastbuf, sizeof(toastbuf));
+				break;
+
 				/*
 				 * 'E'	The EOF marker of a complete stats file.
 				 */
@@ -3745,6 +3839,8 @@ pgstat_recv_dropdb(PgStat_MsgDropdb *msg, int len)
 			hash_destroy(dbentry->tables);
 		if (dbentry->functions != NULL)
 			hash_destroy(dbentry->functions);
+		if (dbentry->toastactivity != NULL)
+			hash_destroy(dbentry->toastactivity);
 
 		if (hash_search(pgStatDBHash,
 						(void *) &dbid,
@@ -3781,7 +3877,8 @@ pgstat_recv_resetcounter(PgStat_MsgResetcounter *msg, int len)
 		hash_destroy(dbentry->tables);
 	if (dbentry->functions != NULL)
 		hash_destroy(dbentry->functions);
-
+	if (dbentry->toastactivity != NULL)
+		hash_destroy(dbentry->toastactivity);
 	dbentry->tables = NULL;
 	dbentry->functions = NULL;
 
@@ -4444,6 +4541,60 @@ pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len)
 	}
 }
 
+/* ----------
+ * pgstat_recv_toaststat() -
+ *
+ *	Count what the backend has done.
+ * ----------
+ */
+static void
+pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len)
+{
+	PgStat_ToastEntry *toastmsg = &(msg->m_entry[0]);
+	PgStat_StatDBEntry *dbentry;
+	PgStat_StatToastEntry *toastentry;
+	int			i;
+	bool		found;
+
+	dbentry = pgstat_get_db_entry(msg->m_databaseid, true);
+
+	/*
+	 * Process all TOAST entries in the message.
+	 */
+	for (i = 0; i < msg->m_nentries; i++, toastmsg++)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &(toastmsg->attr),
+														 HASH_ENTER, &found);
+
+		if (!found)
+		{
+			/*
+			 * If it's a new entry, initialize counters to the values
+			 * we just got.
+			 */
+			toastentry->t_numexternalized = toastmsg->t_numexternalized;
+			toastentry->t_numcompressed = toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess = toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_orig = toastmsg->t_size_orig;
+			toastentry->t_size_compressed = toastmsg->t_size_compressed;
+			toastentry->t_comp_time = toastmsg->t_comp_time;
+		}
+		else
+		{
+			/*
+			 * Otherwise add the values to the existing entry.
+			 */
+			toastentry->t_numexternalized += toastmsg->t_numexternalized;
+			toastentry->t_numcompressed += toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess += toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_orig += toastmsg->t_size_orig;
+			toastentry->t_size_compressed += toastmsg->t_size_compressed;
+			toastentry->t_comp_time += toastmsg->t_comp_time;
+		}
+	}
+}
+
 /* ----------
  * pgstat_recv_subscription_drop() -
  *
diff --git a/src/backend/utils/activity/Makefile b/src/backend/utils/activity/Makefile
index 25a967ab7d..229cdaefd3 100644
--- a/src/backend/utils/activity/Makefile
+++ b/src/backend/utils/activity/Makefile
@@ -26,6 +26,7 @@ OBJS = \
 	pgstat_subscription.o \
 	pgstat_wal.o \
 	pgstat_slru.o \
+	pgstat_toast.o \
 	wait_event.o
 
 include $(top_srcdir)/src/backend/common.mk
diff --git a/src/backend/utils/activity/pgstat_toast.c b/src/backend/utils/activity/pgstat_toast.c
new file mode 100644
index 0000000000..b6ba62c302
--- /dev/null
+++ b/src/backend/utils/activity/pgstat_toast.c
@@ -0,0 +1,157 @@
+/* -------------------------------------------------------------------------
+ *
+ * pgstat_toast.c
+ *	  Implementation of TOAST statistics.
+ *
+ * This file contains the implementation of TOAST statistics. It is kept
+ * separate from pgstat.c to enforce the line between the statistics access /
+ * storage implementation and the details about individual types of
+ * statistics.
+ *
+ * Copyright (c) 2001-2022, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/activity/pgstat_toast.c
+ * -------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "utils/pgstat_internal.h"
+#include "utils/timestamp.h"
+
+/*
+ * Indicates if backend has some function stats that it hasn't yet
+ * sent to the collector.
+ */
+bool		have_toast_stats = false;
+
+/*
+ * Backends store per-toast-column info that's waiting to be sent to the collector
+ * in this hash table (indexed by column's PgStat_BackendAttrIdentifier).
+ */
+static HTAB *pgStatToastActions = NULL;
+
+/*
+ * Report TOAST activity
+ * Called by toast_helper functions.
+ */
+void
+pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							instr_time start_time)
+{
+	PgStat_BackendAttrIdentifier toastattr = { relid, attr };
+	PgStat_BackendToastEntry *htabent;
+	instr_time	time_spent;
+	bool		found;
+
+	if (pgStatSock == PGINVALID_SOCKET || !pgstat_track_toast)
+		return;
+
+	INSTR_TIME_SET_CURRENT(time_spent);
+	INSTR_TIME_SUBTRACT(time_spent, start_time);
+
+	if (!pgStatToastActions)
+	{
+		/* First time through - initialize toast stat table */
+		HASHCTL		hash_ctl;
+
+		hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+		hash_ctl.entrysize = sizeof(PgStat_BackendToastEntry);
+		pgStatToastActions = hash_create("TOAST stat entries",
+									  PGSTAT_TOAST_HASH_SIZE,
+									  &hash_ctl,
+									  HASH_ELEM | HASH_BLOBS);
+	}
+
+	/* Get the stats entry for this TOAST attribute, create if necessary */
+	htabent = hash_search(pgStatToastActions, &toastattr,
+						  HASH_ENTER, &found);
+	if (!found)
+	{
+		MemSet(&htabent->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	/* update counters */
+	if (externalized)
+	{
+		htabent->t_counts.t_numexternalized++;
+	}
+	if (compressed)
+	{
+		htabent->t_counts.t_numcompressed++;
+		htabent->t_counts.t_size_orig+=old_size;
+		if (new_size)
+		{
+			htabent->t_counts.t_numcompressionsuccess++;
+			htabent->t_counts.t_size_compressed+=new_size;
+		}
+	}
+	/* record time spent */
+	INSTR_TIME_ADD(htabent->t_counts.t_comp_time, time_spent);
+
+	/* indicate that we have something to send */
+	have_toast_stats = true;
+}
+
+/*
+ * Subroutine for pgstat_report_stat: populate and send a toast stat message
+ */
+void
+pgstat_send_toaststats(void)
+{
+	static const PgStat_ToastCounts all_zeroes;
+
+	PgStat_MsgToaststat msg;
+	PgStat_BackendToastEntry *entry;
+	HASH_SEQ_STATUS tstat;
+
+	if (pgStatToastActions == NULL)
+		return;
+
+	pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_TOASTSTAT);
+	msg.m_databaseid = MyDatabaseId;
+	msg.m_nentries = 0;
+
+	hash_seq_init(&tstat, pgStatToastActions);
+	while ((entry = (PgStat_BackendToastEntry *) hash_seq_search(&tstat)) != NULL)
+	{
+		PgStat_ToastEntry *m_ent;
+
+		/* Skip it if no counts accumulated since last time */
+		if (memcmp(&entry->t_counts, &all_zeroes,
+				   sizeof(PgStat_ToastCounts)) == 0)
+			continue;
+
+		/* need to convert format of time accumulators */
+		m_ent = &msg.m_entry[msg.m_nentries];
+		m_ent->attr = entry->attr;
+		m_ent->t_numexternalized = entry->t_counts.t_numexternalized;
+		m_ent->t_numcompressed = entry->t_counts.t_numcompressed;
+		m_ent->t_numcompressionsuccess = entry->t_counts.t_numcompressionsuccess;
+		m_ent->t_size_orig = entry->t_counts.t_size_orig;
+		m_ent->t_size_compressed = entry->t_counts.t_size_compressed;
+		m_ent->t_comp_time = INSTR_TIME_GET_MICROSEC(entry->t_counts.t_comp_time);
+
+		if (++msg.m_nentries >= PGSTAT_NUM_TOASTENTRIES)
+		{
+			pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+						msg.m_nentries * sizeof(PgStat_ToastEntry));
+			msg.m_nentries = 0;
+		}
+
+		/* reset the entry's counts */
+		MemSet(&entry->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	if (msg.m_nentries > 0)
+		pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+					msg.m_nentries * sizeof(PgStat_ToastEntry));
+
+	have_toast_stats = false;
+}
+
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index ce84525d40..a1f74c74ff 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -410,6 +410,78 @@ pg_stat_get_function_self_time(PG_FUNCTION_ARGS)
 	PG_RETURN_FLOAT8(((double) funcentry->f_self_time) / 1000.0);
 }
 
+Datum
+pg_stat_get_toast_externalizations(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numexternalized);
+}
+
+Datum
+pg_stat_get_toast_compressions(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressed);
+}
+
+Datum
+pg_stat_get_toast_compressionsuccesses(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressionsuccess);
+}
+
+Datum
+pg_stat_get_toast_originalsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_orig);
+}
+
+Datum
+pg_stat_get_toast_compressedsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_compressed);
+}
+
+Datum
+pg_stat_get_toast_total_time(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_comp_time);
+}
+
 Datum
 pg_stat_get_backend_idset(PG_FUNCTION_ARGS)
 {
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 9e8ab1420d..339d2553d4 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -1557,6 +1557,15 @@ static struct config_bool ConfigureNamesBool[] =
 		true,
 		NULL, NULL, NULL
 	},
+	{
+		{"track_toast", PGC_SUSET, STATS_COLLECTOR,
+			gettext_noop("Collects statistics on TOAST activity."),
+			NULL
+		},
+		&pgstat_track_toast,
+		false,
+		NULL, NULL, NULL
+	},
 	{
 		{"track_io_timing", PGC_SUSET, STATS_COLLECTOR,
 			gettext_noop("Collects timing statistics for database I/O activity."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 93d221a37b..4c3b7ae29b 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -613,6 +613,7 @@
 #track_io_timing = off
 #track_wal_io_timing = off
 #track_functions = none			# none, pl, all
+#track_toast = off
 #stats_temp_directory = 'pg_stat_tmp'
 
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 25304430f4..6d7ba55293 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5673,6 +5673,31 @@
   proparallel => 'r', prorettype => 'float8', proargtypes => 'oid',
   prosrc => 'pg_stat_get_function_self_time' },
 
+{ oid => '9700', descr => 'statistics: number of TOAST externalizations',
+  proname => 'pg_stat_get_toast_externalizations', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_externalizations' },
+{ oid => '9701', descr => 'statistics: number of TOAST compressions',
+  proname => 'pg_stat_get_toast_compressions', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressions' },
+  { oid => '9702', descr => 'statistics: number of successful TOAST compressions',
+  proname => 'pg_stat_get_toast_compressionsuccesses', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressionsuccesses' },
+{ oid => '9703', descr => 'statistics: total original size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_originalsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_originalsizesum' },
+{ oid => '9704', descr => 'statistics: total compressed size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_compressedsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressedsizesum' },
+{ oid => '9705', descr => 'statistics: total time spend TOASTing data',
+  proname => 'pg_stat_get_toast_total_time', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_total_time' },
+
 { oid => '3037',
   descr => 'statistics: number of scans done for table/index in current transaction',
   proname => 'pg_stat_get_xact_numscans', provolatile => 'v',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 534d595ca0..7c8191aefe 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -33,7 +33,6 @@
 /* Default directory to store temporary statistics data in */
 #define PG_STAT_TMP_DIR		"pg_stat_tmp"
 
-
 /* Values for track_functions GUC variable --- order is significant! */
 typedef enum TrackFunctionsLevel
 {
@@ -252,6 +251,7 @@ typedef enum StatMsgType
 	PGSTAT_MTYPE_DISCONNECT,
 	PGSTAT_MTYPE_SUBSCRIPTIONDROP,
 	PGSTAT_MTYPE_SUBSCRIPTIONERROR,
+	PGSTAT_MTYPE_TOASTSTAT,
 } StatMsgType;
 
 /* ----------
@@ -726,6 +726,80 @@ typedef struct PgStat_MsgDisconnect
 	SessionEndType m_cause;
 } PgStat_MsgDisconnect;
 
+/* ----------
+ * PgStat_BackendAttrIdentifier	Identifier for a single attribute/column (OID + attr)
+ * Used as a hashable identifier for (e.g.) TOAST columns
+ * ----------
+ */
+typedef struct PgStat_BackendAttrIdentifier
+{
+	Oid			relid;
+	int			attr;
+} PgStat_BackendAttrIdentifier;
+
+/* ----------
+ * PgStat_ToastCounts	The actual per-TOAST counts kept by a backend
+ *
+ * This struct should contain only actual event counters, because we memcmp
+ * it against zeroes to detect whether there are any counts to transmit.
+ *
+ * Note that the time counters are in instr_time format here.  We convert to
+ * microseconds in PgStat_Counter format when transmitting to the collector.
+ * ----------
+ */
+typedef struct PgStat_ToastCounts
+{
+	PgStat_Counter	t_numexternalized;
+	PgStat_Counter	t_numcompressed;
+	PgStat_Counter	t_numcompressionsuccess;
+	uint64		t_size_orig;
+	uint64		t_size_compressed;
+	instr_time	t_comp_time;
+} PgStat_ToastCounts;
+
+/* ----------
+ * PgStat_BackendToastEntry	Entry in backend's per-toast-attr hash table
+ * ----------
+ */
+typedef struct PgStat_BackendToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_ToastCounts 		t_counts;
+} PgStat_BackendToastEntry;
+
+/* ----------
+ * PgStat_ToastEntry			Per-TOAST-column info in a MsgToaststat
+ * ----------
+ */
+typedef struct PgStat_ToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_Counter 			t_numexternalized;
+	PgStat_Counter 			t_numcompressed;
+	PgStat_Counter 			t_numcompressionsuccess;
+	uint64		   		t_size_orig;
+	uint64		   		t_size_compressed;
+	PgStat_Counter			t_comp_time;	/* time in microseconds */
+} PgStat_ToastEntry;
+
+/* ----------
+ * PgStat_MsgToaststat			Sent by the backend to report function
+ *								usage statistics.
+ * ----------
+ */
+#define PGSTAT_NUM_TOASTENTRIES	\
+	((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - sizeof(int))  \
+	 / sizeof(PgStat_ToastEntry))
+
+typedef struct PgStat_MsgToaststat
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+	int			m_nentries;
+	PgStat_ToastEntry m_entry[PGSTAT_NUM_TOASTENTRIES];
+} PgStat_MsgToaststat;
+
+
 /* ----------
  * PgStat_Msg					Union over all possible messages.
  * ----------
@@ -754,6 +828,7 @@ typedef union PgStat_Msg
 	PgStat_MsgSLRU msg_slru;
 	PgStat_MsgFuncstat msg_funcstat;
 	PgStat_MsgFuncpurge msg_funcpurge;
+	PgStat_MsgToaststat msg_toaststat;
 	PgStat_MsgRecoveryConflict msg_recoveryconflict;
 	PgStat_MsgDeadlock msg_deadlock;
 	PgStat_MsgTempFile msg_tempfile;
@@ -774,7 +849,7 @@ typedef union PgStat_Msg
  * ------------------------------------------------------------
  */
 
-#define PGSTAT_FILE_FORMAT_ID	0x01A5BCA6
+#define PGSTAT_FILE_FORMAT_ID	0x01A5BCA7
 
 /*
  * Archiver statistics kept in the stats collector
@@ -864,6 +939,7 @@ typedef struct PgStat_StatDBEntry
 	 */
 	HTAB	   *tables;
 	HTAB	   *functions;
+	HTAB	   *toastactivity;
 } PgStat_StatDBEntry;
 
 /* ----------
@@ -936,6 +1012,22 @@ typedef struct PgStat_StatSubEntry
 } PgStat_StatSubEntry;
 
 /* ----------
+ * PgStat_StatToastEntry			The collector's data per TOAST attribute
+ * ----------
+ */
+typedef struct PgStat_StatToastEntry
+{
+	PgStat_BackendAttrIdentifier t_id;
+	PgStat_Counter t_numexternalized;
+	PgStat_Counter t_numcompressed;
+	PgStat_Counter t_numcompressionsuccess;
+	uint64		   t_size_orig;
+	uint64		   t_size_compressed;
+	PgStat_Counter t_comp_time;	/* time in microseconds */
+} PgStat_StatToastEntry;
+
+
+/*
  * PgStat_StatTabEntry			The collector's data per table (or index)
  * ----------
  */
@@ -1027,6 +1119,7 @@ extern PgStat_BgWriterStats *pgstat_fetch_stat_bgwriter(void);
 extern PgStat_CheckpointerStats *pgstat_fetch_stat_checkpointer(void);
 extern PgStat_StatDBEntry *pgstat_fetch_stat_dbentry(Oid dbid);
 extern PgStat_StatFuncEntry *pgstat_fetch_stat_funcentry(Oid funcid);
+extern PgStat_StatToastEntry *pgstat_fetch_stat_toastentry(Oid rel_id, int attr);
 extern PgStat_GlobalStats *pgstat_fetch_global(void);
 extern PgStat_StatReplSlotEntry *pgstat_fetch_replslot(NameData slotname);
 extern PgStat_StatSubEntry *pgstat_fetch_stat_subscription(Oid subid);
@@ -1090,6 +1183,7 @@ extern void pgstat_end_function_usage(PgStat_FunctionCallUsage *fcu,
 extern PgStat_BackendFunctionEntry *find_funcstat_entry(Oid func_id);
 
 
+
 /*
  * Functions in pgstat_relation.c
  */
@@ -1199,6 +1293,17 @@ extern void pgstat_report_subscription_drop(Oid subid);
 
 extern void pgstat_send_wal(bool force);
 
+/*
+ * Functions in pgstat_toast.c
+ */
+
+extern void pgstat_send_toaststats(void);
+extern void pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							instr_time start_time);
 
 /*
  * Variables in pgstat.c
@@ -1207,6 +1312,7 @@ extern void pgstat_send_wal(bool force);
 /* GUC parameters */
 extern PGDLLIMPORT bool pgstat_track_counts;
 extern PGDLLIMPORT int pgstat_track_functions;
+extern PGDLLIMPORT bool pgstat_track_toast;
 extern char *pgstat_stat_directory;
 extern char *pgstat_stat_tmpname;
 extern char *pgstat_stat_filename;
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index abbb4f8d96..44b0aeb7af 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -27,6 +27,7 @@
 #define PGSTAT_DB_HASH_SIZE		16
 #define PGSTAT_TAB_HASH_SIZE	512
 #define PGSTAT_FUNCTION_HASH_SIZE	512
+#define PGSTAT_TOAST_HASH_SIZE	64
 #define PGSTAT_SUBSCRIPTION_HASH_SIZE	32
 #define PGSTAT_REPLSLOT_HASH_SIZE	32
 
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index 423b9b99fb..91358a5b62 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -2128,6 +2128,23 @@ pg_stat_sys_tables| SELECT pg_stat_all_tables.relid,
     pg_stat_all_tables.autoanalyze_count
    FROM pg_stat_all_tables
   WHERE ((pg_stat_all_tables.schemaname = ANY (ARRAY['pg_catalog'::name, 'information_schema'::name])) OR (pg_stat_all_tables.schemaname ~ '^pg_toast'::text));
+pg_stat_toast| SELECT n.nspname AS schemaname,
+    a.attrelid AS reloid,
+    a.attnum,
+    c.relname,
+    a.attname,
+    a.attstorage AS storagemethod,
+    pg_stat_get_toast_externalizations(a.attrelid, (a.attnum)::integer) AS externalized,
+    a.attcompression AS compressmethod,
+    pg_stat_get_toast_compressions(a.attrelid, (a.attnum)::integer) AS compressattempts,
+    pg_stat_get_toast_compressionsuccesses(a.attrelid, (a.attnum)::integer) AS compresssuccesses,
+    pg_stat_get_toast_compressedsizesum(a.attrelid, (a.attnum)::integer) AS compressedsize,
+    pg_stat_get_toast_originalsizesum(a.attrelid, (a.attnum)::integer) AS originalsize,
+    pg_stat_get_toast_total_time(a.attrelid, (a.attnum)::integer) AS total_time
+   FROM ((pg_attribute a
+     JOIN pg_class c ON ((c.oid = a.attrelid)))
+     LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace)))
+  WHERE (pg_stat_get_toast_externalizations(a.attrelid, (a.attnum)::integer) IS NOT NULL);
 pg_stat_user_functions| SELECT p.oid AS funcid,
     n.nspname AS schemaname,
     p.proname AS funcname,
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 06a1d2f229..b9514e1f34 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -11,6 +11,32 @@ SHOW track_counts;  -- must be on
  on
 (1 row)
 
+-- prepare and fill the pg_stat_toast table now:
+SHOW track_toast;
+ track_toast 
+-------------
+ off
+(1 row)
+
+SET track_toast TO on;
+SHOW track_toast;
+ track_toast 
+-------------
+ on
+(1 row)
+
+TABLE pg_stat_toast; -- view exists
+ schemaname | reloid | attnum | relname | attname | storagemethod | externalized | compressmethod | compressattempts | compresssuccesses | compressedsize | originalsize | total_time 
+------------+--------+--------+---------+---------+---------------+--------------+----------------+------------------+-------------------+----------------+--------------+------------
+(0 rows)
+
+CREATE TABLE toast_test (cola TEXT, colb TEXT, colc TEXT , cold TEXT);
+ALTER TABLE toast_test ALTER colb SET STORAGE EXTERNAL;
+ALTER TABLE toast_test ALTER colc SET STORAGE MAIN;
+ALTER TABLE toast_test ALTER cold SET STORAGE PLAIN;
+INSERT INTO toast_test VALUES (repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100) );
+-- make sure we don't interfere with the other tests:
+SET track_toast TO off;
 -- ensure that both seqscan and indexscan plans are allowed
 SET enable_seqscan TO on;
 SET enable_indexscan TO on;
@@ -255,6 +281,42 @@ SELECT pg_stat_get_tuples_hot_updated('brin_hot'::regclass::oid);
 
 DROP TABLE brin_hot;
 DROP FUNCTION wait_for_hot_stats();
+-- now check that the track_toast stuff worked:
+SELECT attname
+	,storagemethod
+	,externalized
+	,compressmethod
+	,compressattempts
+	,compresssuccesses
+	,compressedsize < originalsize AS compression_works
+	, total_time > 0 AS takes_time
+FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY attname;
+ attname | storagemethod | externalized | compressmethod | compressattempts | compresssuccesses | compression_works | takes_time 
+---------+---------------+--------------+----------------+------------------+-------------------+-------------------+------------
+ cola    | x             |            1 |                |                1 |                 1 | t                 | t
+ colb    | e             |            1 |                |                0 |                 0 | f                 | t
+ colc    | m             |            0 |                |                1 |                 1 | t                 | t
+(3 rows)
+
+SELECT compressattempts=0 AS external_doesnt_compress FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'e';
+ external_doesnt_compress 
+--------------------------
+ t
+(1 row)
+
+SELECT externalized=0 AS main_doesnt_externalize FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'm';
+ main_doesnt_externalize 
+-------------------------
+ t
+(1 row)
+
+DROP TABLE toast_test;
+SELECT count(*) FROM pg_stat_toast WHERE relname = 'toast_test';
+ count 
+-------
+     0
+(1 row)
+
 -- ensure that stats accessors handle NULL input correctly
 SELECT pg_stat_get_replication_slot(NULL);
  pg_stat_get_replication_slot 
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index ae1ec173e3..b30de2fa7a 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -8,6 +8,20 @@
 -- conditio sine qua non
 SHOW track_counts;  -- must be on
 
+-- prepare and fill the pg_stat_toast table now:
+SHOW track_toast;
+SET track_toast TO on;
+SHOW track_toast;
+TABLE pg_stat_toast; -- view exists
+
+CREATE TABLE toast_test (cola TEXT, colb TEXT, colc TEXT , cold TEXT);
+ALTER TABLE toast_test ALTER colb SET STORAGE EXTERNAL;
+ALTER TABLE toast_test ALTER colc SET STORAGE MAIN;
+ALTER TABLE toast_test ALTER cold SET STORAGE PLAIN;
+INSERT INTO toast_test VALUES (repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100) );
+-- make sure we don't interfere with the other tests:
+SET track_toast TO off;
+
 -- ensure that both seqscan and indexscan plans are allowed
 SET enable_seqscan TO on;
 SET enable_indexscan TO on;
@@ -228,6 +242,20 @@ SELECT pg_stat_get_tuples_hot_updated('brin_hot'::regclass::oid);
 DROP TABLE brin_hot;
 DROP FUNCTION wait_for_hot_stats();
 
+-- now check that the track_toast stuff worked:
+SELECT attname
+	,storagemethod
+	,externalized
+	,compressmethod
+	,compressattempts
+	,compresssuccesses
+	,compressedsize < originalsize AS compression_works
+	, total_time > 0 AS takes_time
+FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY attname;
+SELECT compressattempts=0 AS external_doesnt_compress FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'e';
+SELECT externalized=0 AS main_doesnt_externalize FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'm';
+DROP TABLE toast_test;
+SELECT count(*) FROM pg_stat_toast WHERE relname = 'toast_test';
 
 -- ensure that stats accessors handle NULL input correctly
 SELECT pg_stat_get_replication_slot(NULL);

 doc/src/sgml/config.sgml                      |  26 ++++
 doc/src/sgml/monitoring.sgml                  | 163 ++++++++++++++++++++++++++
 doc/src/sgml/storage.sgml                     |  12 +-
 src/backend/access/table/toast_helper.c       |  40 +++++++
 src/backend/catalog/system_views.sql          |  20 ++++
 src/backend/postmaster/pgstat.c               | 156 +++++++++++++++++++++++-
 src/backend/utils/activity/Makefile           |   1 +
 src/backend/utils/activity/pgstat_toast.c     | 157 +++++++++++++++++++++++++
 src/backend/utils/adt/pgstatfuncs.c           |  72 ++++++++++++
 src/backend/utils/misc/guc.c                  |   9 ++
 src/backend/utils/misc/postgresql.conf.sample |   1 +
 src/include/catalog/pg_proc.dat               |  25 ++++
 src/include/pgstat.h                          | 101 ++++++++++++++++
 src/include/utils/pgstat_internal.h           |   1 +
 src/test/regress/expected/rules.out           |  17 +++
 src/test/regress/expected/stats.out           |  62 ++++++++++
 src/test/regress/sql/stats.sql                |  28 +++++
 17 files changed, 886 insertions(+), 5 deletions(-)

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 43e4ade83e..544c1d7041 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -7935,6 +7935,32 @@ COPY postgres_log FROM '/full/path/to/logfile.csv' WITH csv;
       </listitem>
      </varlistentry>
 
+     <varlistentry id="guc-track-toast" xreflabel="track_toast">
+      <term><varname>track_toast</varname> (<type>boolean</type>)
+      <indexterm>
+       <primary><varname>track_toast</varname> configuration parameter</primary>
+      </indexterm>
+      </term>
+      <listitem>
+       <para>
+        Enables tracking of <link linkend="storage-toast">TOAST</link> activities.
+        Compressions and externalizations are tracked.
+        The default is <literal>off</literal>.
+        Only superusers can change this setting.
+       </para>
+
+       <note>
+        <para>
+        Be aware that this feature, depending on the amount of TOASTable columns in
+        your databases, may significantly increase the size of the statistics files
+        and the workload of the statistics collector. If your databases have a very high 
+        amount of TOASTable colums, it is recommended to only temporarily activate this
+        setting to assess the right compression and storage method for a column.
+        </para>
+       </note>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="guc-stats-temp-directory" xreflabel="stats_temp_directory">
       <term><varname>stats_temp_directory</varname> (<type>string</type>)
       <indexterm>
diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml
index 3b9172f65b..cd0a5bea35 100644
--- a/doc/src/sgml/monitoring.sgml
+++ b/doc/src/sgml/monitoring.sgml
@@ -610,6 +610,17 @@ postgres   27093  0.0  0.0  30096  2752 ?        Ss   11:34   0:00 postgres: ser
       yet included in <structname>pg_stat_user_functions</structname>).</entry>
      </row>
 
+     <row>
+      <entry><structname>pg_stat_toast</structname><indexterm><primary>pg_stat_toast</primary></indexterm></entry>
+      <entry>
+       One row for each column that has ever been TOASTed (compressed and/or externalized).
+       Showing the number of externalizations, compression attempts / successes, compressed and
+       uncompressed sizes etc.
+       <link linkend="monitoring-pg-stat-toast-view">
+       <structname>pg_stat_toast</structname></link> for details.
+      </entry>
+     </row>
+
      <row>
       <entry><structname>pg_stat_slru</structname><indexterm><primary>pg_stat_slru</primary></indexterm></entry>
       <entry>One row per SLRU, showing statistics of operations. See
@@ -4946,6 +4957,158 @@ SELECT pid, wait_event_type, wait_event FROM pg_stat_activity WHERE wait_event i
 
  </sect2>
 
+ <sect2 id="monitoring-pg-stat-toast-view">
+  <title><structname>pg_stat_toast</structname></title>
+
+  <indexterm>
+   <primary>pg_stat_toast</primary>
+  </indexterm>
+
+  <para>
+   The <structname>pg_stat_toast</structname> view will contain
+   one row for each column of variable size that has been TOASTed since 
+   the last statistics reset. The <xref linkend="guc-track-toast"/> parameter
+   controls whether TOAST activities are tracked or not.
+  </para>
+
+  <table id="pg-stat-toast-view" xreflabel="pg_stat_toast">
+   <title><structname>pg_stat_toast</structname> View</title>
+   <tgroup cols="1">
+    <thead>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       Column Type
+      </para>
+      <para>
+       Description
+      </para></entry>
+     </row>
+    </thead>
+
+    <tbody>
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>schemaname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the schema the relation is in
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>reloid</structfield> <type>oid</type>
+      </para>
+      <para>
+       OID of the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>attnum</structfield> <type>int</type>
+      </para>
+      <para>
+       Attribute (column) number in the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>relname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the relation
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>attname</structfield> <type>name</type>
+      </para>
+      <para>
+       Name of the attribute (column)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>storagemethod</structfield> <type>char</type>
+      </para>
+      <para>
+       Storage method of the attribute
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>externalized</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times this attribute was externalized (pushed to TOAST relation)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressmethod</structfield> <type>char</type>
+      </para>
+      <para>
+       Current compression method of the attribute (empty means default)
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressattempts</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times compression of this attribute was attempted
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compresssuccesses</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Number of times compression of this attribute was successful
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>compressedsize</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total size of all compressed datums
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>originalsize</structfield> <type>bigint</type>
+      </para>
+      <para>
+       Total size of all compressed datums before compression
+      </para></entry>
+     </row>
+
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>total_time</structfield> <type>double precision</type>
+      </para>
+      <para>
+       Total time spent TOASTing this attribute, in microseconds.
+      </para></entry>
+     </row>
+
+    </tbody>
+   </tgroup>
+  </table>
+
+ </sect2>
+
  <sect2 id="monitoring-pg-stat-slru-view">
   <title><structname>pg_stat_slru</structname></title>
 
diff --git a/doc/src/sgml/storage.sgml b/doc/src/sgml/storage.sgml
index f4b9f66589..d0e165d5f1 100644
--- a/doc/src/sgml/storage.sgml
+++ b/doc/src/sgml/storage.sgml
@@ -517,6 +517,15 @@ pages). There was no run time difference compared to an un-<acronym>TOAST</acron
 comparison table, in which all the HTML pages were cut down to 7 kB to fit.
 </para>
 
+<para>
+When you enable <xref linkend="guc-track-toast"/>, the system view
+<link linkend="monitoring-pg-stat-toast-view"><structname>pg_stat_toast</structname>
+</link> provides details on the number and effect of compression attempts,
+number of externalizations and some more useful information that enables you
+to decide if a different storage method and/or compression method would suite a
+column better.
+</para>
+
 </sect2>
 
 <sect2 id="storage-toast-inmemory">
@@ -1069,7 +1078,8 @@ data. Empty in ordinary tables.</entry>
   <type>struct varlena</type>, which includes the total length of the stored
   value and some flag bits.  Depending on the flags, the data can be either
   inline or in a <acronym>TOAST</acronym> table;
-  it might be compressed, too (see <xref linkend="storage-toast"/>).
+  it might be compressed, too (see <xref linkend="storage-toast"/> and 
+  <xref linkend="monitoring-pg-stat-toast-view"/>).
 
  </para>
  </sect2>
diff --git a/src/backend/access/table/toast_helper.c b/src/backend/access/table/toast_helper.c
index 0cc5a30f9b..98d10a0670 100644
--- a/src/backend/access/table/toast_helper.c
+++ b/src/backend/access/table/toast_helper.c
@@ -19,7 +19,9 @@
 #include "access/toast_helper.h"
 #include "access/toast_internals.h"
 #include "catalog/pg_type_d.h"
+#include "pgstat.h"
 
+PGDLLIMPORT bool pgstat_track_toast;
 
 /*
  * Prepare to TOAST a tuple.
@@ -229,7 +231,12 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 	Datum	   *value = &ttc->ttc_values[attribute];
 	Datum		new_value;
 	ToastAttrInfo *attr = &ttc->ttc_attr[attribute];
+	instr_time	start_time;
 
+	if (pgstat_track_toast)
+	{
+		INSTR_TIME_SET_CURRENT(start_time);
+	}
 	new_value = toast_compress_datum(*value, attr->tai_compression);
 
 	if (DatumGetPointer(new_value) != NULL)
@@ -239,6 +246,15 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 			pfree(DatumGetPointer(*value));
 		*value = new_value;
 		attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
+		if (pgstat_track_toast)
+		{
+			pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							attr->tai_size,
+							VARSIZE(DatumGetPointer(*value)),
+							start_time);
+		}
 		attr->tai_size = VARSIZE(DatumGetPointer(*value));
 		ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
 	}
@@ -246,6 +262,15 @@ toast_tuple_try_compression(ToastTupleContext *ttc, int attribute)
 	{
 		/* incompressible, ignore on subsequent compression passes */
 		attr->tai_colflags |= TOASTCOL_INCOMPRESSIBLE;
+		if (pgstat_track_toast)
+		{
+			pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							false,
+							true,
+							0,
+							0,
+							start_time);
+		}
 	}
 }
 
@@ -258,6 +283,12 @@ toast_tuple_externalize(ToastTupleContext *ttc, int attribute, int options)
 	Datum	   *value = &ttc->ttc_values[attribute];
 	Datum		old_value = *value;
 	ToastAttrInfo *attr = &ttc->ttc_attr[attribute];
+	instr_time	start_time;
+
+	if (pgstat_track_toast)
+	{
+		INSTR_TIME_SET_CURRENT(start_time);
+	}
 
 	attr->tai_colflags |= TOASTCOL_IGNORE;
 	*value = toast_save_datum(ttc->ttc_rel, old_value, attr->tai_oldexternal,
@@ -266,6 +297,15 @@ toast_tuple_externalize(ToastTupleContext *ttc, int attribute, int options)
 		pfree(DatumGetPointer(old_value));
 	attr->tai_colflags |= TOASTCOL_NEEDS_FREE;
 	ttc->ttc_flags |= (TOAST_NEEDS_CHANGE | TOAST_NEEDS_FREE);
+	if (pgstat_track_toast)
+	{
+		pgstat_report_toast_activity(ttc->ttc_rel->rd_rel->oid, attribute,
+							true,
+							false,
+							0,
+							0,
+							start_time);
+}
 }
 
 /*
diff --git a/src/backend/catalog/system_views.sql b/src/backend/catalog/system_views.sql
index 9eaa51df29..e9cce5c51a 100644
--- a/src/backend/catalog/system_views.sql
+++ b/src/backend/catalog/system_views.sql
@@ -1066,6 +1066,26 @@ CREATE VIEW pg_stat_user_functions AS
     WHERE P.prolang != 12  -- fast check to eliminate built-in functions
           AND pg_stat_get_function_calls(P.oid) IS NOT NULL;
 
+
+CREATE OR REPLACE VIEW pg_stat_toast AS
+ SELECT
+    n.nspname AS schemaname,
+    a.attrelid AS reloid,
+    a.attnum AS attnum,
+    c.relname AS relname,
+    a.attname AS attname,
+    attstorage AS storagemethod,
+    pg_stat_get_toast_externalizations(a.attrelid,a.attnum) AS externalized,
+    attcompression AS compressmethod,
+    pg_stat_get_toast_compressions(a.attrelid,a.attnum) AS compressattempts,
+    pg_stat_get_toast_compressionsuccesses(a.attrelid,a.attnum) AS compresssuccesses,
+    pg_stat_get_toast_compressedsizesum(a.attrelid,a.attnum) AS compressedsize,
+    pg_stat_get_toast_originalsizesum(a.attrelid,a.attnum) AS originalsize,
+    pg_stat_get_toast_total_time(a.attrelid,a.attnum) AS total_time
+   FROM pg_attribute a
+   JOIN pg_class c ON c.oid = a.attrelid
+   LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
+  WHERE pg_stat_get_toast_externalizations(a.attrelid,a.attnum) IS NOT NULL;
 CREATE VIEW pg_stat_xact_user_functions AS
     SELECT
             P.oid AS funcid,
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index ef1cba61a6..66e1263c44 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -116,7 +116,7 @@ static void pgstat_reset_subscription(PgStat_StatSubEntry *subentry, TimestampTz
 static void pgstat_write_statsfiles(bool permanent, bool allDbs);
 static void pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent);
 static HTAB *pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep);
-static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+static void pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 									 bool permanent);
 static void backend_read_statsfile(void);
 
@@ -159,6 +159,7 @@ static void pgstat_recv_replslot(PgStat_MsgReplSlot *msg, int len);
 static void pgstat_recv_tempfile(PgStat_MsgTempFile *msg, int len);
 static void pgstat_recv_subscription_drop(PgStat_MsgSubscriptionDrop *msg, int len);
 static void pgstat_recv_subscription_error(PgStat_MsgSubscriptionError *msg, int len);
+static void pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len);
 
 
 /* ----------
@@ -946,6 +947,9 @@ pgstat_report_stat(bool disconnect)
 	/* Now, send function statistics */
 	pgstat_send_funcstats();
 
+	/* Now, send TOAST statistics */
+	pgstat_send_toaststats();
+
 	/* Send WAL statistics */
 	pgstat_send_wal(true);
 
@@ -1434,6 +1438,33 @@ pgstat_fetch_stat_funcentry(Oid func_id)
 	return funcentry;
 }
 
+/* ----------
+ *	Support function for the SQL-callable pgstat* functions. Returns
+ *	the collected statistics for one TOAST attribute or NULL.
+ * ----------
+ */
+PgStat_StatToastEntry *
+pgstat_fetch_stat_toastentry(Oid rel_id, int attr)
+{
+	PgStat_StatDBEntry *dbentry;
+	PgStat_BackendAttrIdentifier toast_id = { rel_id, attr };
+	PgStat_StatToastEntry *toastentry = NULL;
+
+	/* load the stats file if needed */
+	backend_read_statsfile();
+
+	/* Lookup our database, then find the requested TOAST activity stats.  */
+	dbentry = pgstat_fetch_stat_dbentry(MyDatabaseId);
+	if (dbentry != NULL && dbentry->toastactivity != NULL)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &toast_id,
+														 HASH_FIND, NULL);
+	}
+
+	return toastentry;
+}
+
 /*
  * Support function for the SQL-callable pgstat* functions. Returns
  * a pointer to the archiver statistics struct.
@@ -1814,6 +1845,10 @@ PgstatCollectorMain(int argc, char *argv[])
 					pgstat_recv_funcpurge(&msg.msg_funcpurge, len);
 					break;
 
+				case PGSTAT_MTYPE_TOASTSTAT:
+					pgstat_recv_toaststat(&msg.msg_toaststat, len);
+					break;
+
 				case PGSTAT_MTYPE_RECOVERYCONFLICT:
 					pgstat_recv_recoveryconflict(&msg.msg_recoveryconflict,
 												 len);
@@ -1950,6 +1985,13 @@ reset_dbentry_counters(PgStat_StatDBEntry *dbentry)
 									 PGSTAT_FUNCTION_HASH_SIZE,
 									 &hash_ctl,
 									 HASH_ELEM | HASH_BLOBS);
+
+	hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+	hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+	dbentry->toastactivity = hash_create("Per-database TOAST",
+									 PGSTAT_TOAST_HASH_SIZE,
+									 &hash_ctl,
+									 HASH_ELEM | HASH_BLOBS);
 }
 
 /*
@@ -2245,7 +2287,7 @@ pgstat_write_statsfiles(bool permanent, bool allDbs)
 	while ((dbentry = (PgStat_StatDBEntry *) hash_seq_search(&hstat)) != NULL)
 	{
 		/*
-		 * Write out the table and function stats for this DB into the
+		 * Write out the table, function and TOAST stats for this DB into the
 		 * appropriate per-DB stat file, if required.
 		 */
 		if (allDbs || pgstat_db_requested(dbentry->databaseid))
@@ -2374,8 +2416,10 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 {
 	HASH_SEQ_STATUS tstat;
 	HASH_SEQ_STATUS fstat;
+	HASH_SEQ_STATUS ostat;
 	PgStat_StatTabEntry *tabentry;
 	PgStat_StatFuncEntry *funcentry;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpout;
 	int32		format_id;
 	Oid			dbid = dbentry->databaseid;
@@ -2430,6 +2474,17 @@ pgstat_write_db_statsfile(PgStat_StatDBEntry *dbentry, bool permanent)
 		(void) rc;				/* we'll check for error with ferror */
 	}
 
+	/*
+	 * Walk through the database's TOAST stats table.
+	 */
+	hash_seq_init(&ostat, dbentry->toastactivity);
+	while ((toastentry = (PgStat_StatToastEntry *) hash_seq_search(&ostat)) != NULL)
+	{
+		fputc('O', fpout);
+		rc = fwrite(toastentry, sizeof(PgStat_StatToastEntry), 1, fpout);
+		(void) rc;				/* we'll check for error with ferror */
+	}
+
 	/*
 	 * No more output to be done. Close the temp file and replace the old
 	 * pgstat.stat with it.  The ferror() check replaces testing for error
@@ -2665,6 +2720,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 				memcpy(dbentry, &dbbuf, sizeof(PgStat_StatDBEntry));
 				dbentry->tables = NULL;
 				dbentry->functions = NULL;
+				dbentry->toastactivity = NULL;
 
 				/*
 				 * In the collector, disregard the timestamp we read from the
@@ -2702,6 +2758,14 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 												 &hash_ctl,
 												 HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
 
+				hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+				hash_ctl.entrysize = sizeof(PgStat_StatToastEntry);
+				hash_ctl.hcxt = pgStatLocalContext;
+				dbentry->toastactivity = hash_create("Per-database toast information",
+												 PGSTAT_TOAST_HASH_SIZE,
+												 &hash_ctl,
+												 HASH_ELEM | HASH_BLOBS | HASH_CONTEXT);
+
 				/*
 				 * If requested, read the data from the database-specific
 				 * file.  Otherwise we just leave the hashtables empty.
@@ -2710,6 +2774,7 @@ pgstat_read_statsfiles(Oid onlydb, bool permanent, bool deep)
 					pgstat_read_db_statsfile(dbentry->databaseid,
 											 dbentry->tables,
 											 dbentry->functions,
+											 dbentry->toastactivity,
 											 permanent);
 
 				break;
@@ -2829,13 +2894,15 @@ done:
  * at the moment though.
  */
 static void
-pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
+pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash, HTAB *toasthash,
 						 bool permanent)
 {
 	PgStat_StatTabEntry *tabentry;
 	PgStat_StatTabEntry tabbuf;
 	PgStat_StatFuncEntry funcbuf;
 	PgStat_StatFuncEntry *funcentry;
+	PgStat_StatToastEntry toastbuf;
+	PgStat_StatToastEntry *toastentry;
 	FILE	   *fpin;
 	int32		format_id;
 	bool		found;
@@ -2949,6 +3016,32 @@ pgstat_read_db_statsfile(Oid databaseid, HTAB *tabhash, HTAB *funchash,
 				memcpy(funcentry, &funcbuf, sizeof(funcbuf));
 				break;
 
+
+				/*
+				 * 'O'	A PgStat_StatToastEntry follows (tOast)
+				 */
+			case 'O':
+				if (fread(&toastbuf, 1, sizeof(PgStat_StatToastEntry),
+						  fpin) != sizeof(PgStat_StatToastEntry))
+				{
+					ereport(pgStatRunningInCollector ? LOG : WARNING,
+							(errmsg("corrupted statistics file \"%s\"",
+									statfile)));
+					goto done;
+				}
+
+				/*
+				 * Skip if TOAST data not wanted.
+				 */
+				if (toasthash == NULL)
+					break;
+
+				toastentry = (PgStat_StatToastEntry *) hash_search(toasthash,
+																 (void *) &toastbuf.t_id,
+																 HASH_ENTER, &found);
+				memcpy(toastentry, &toastbuf, sizeof(toastbuf));
+				break;
+
 				/*
 				 * 'E'	The EOF marker of a complete stats file.
 				 */
@@ -3602,6 +3695,8 @@ pgstat_recv_dropdb(PgStat_MsgDropdb *msg, int len)
 			hash_destroy(dbentry->tables);
 		if (dbentry->functions != NULL)
 			hash_destroy(dbentry->functions);
+		if (dbentry->toastactivity != NULL)
+			hash_destroy(dbentry->toastactivity);
 
 		if (hash_search(pgStatDBHash,
 						(void *) &dbid,
@@ -3635,6 +3730,8 @@ pgstat_recv_resetcounter(PgStat_MsgResetcounter *msg, int len)
 		hash_destroy(dbentry->tables);
 	if (dbentry->functions != NULL)
 		hash_destroy(dbentry->functions);
+	if (dbentry->toastactivity != NULL)
+		hash_destroy(dbentry->toastactivity);
 
 	dbentry->tables = NULL;
 	dbentry->functions = NULL;
@@ -4233,7 +4330,58 @@ pgstat_recv_funcpurge(PgStat_MsgFuncpurge *msg, int len)
 }
 
 /*
- * Process a SUBSCRIPTIONDROP message.
+ *	Count what the backend has done.
+ */
+static void
+pgstat_recv_toaststat(PgStat_MsgToaststat *msg, int len)
+{
+	PgStat_ToastEntry *toastmsg = &(msg->m_entry[0]);
+	PgStat_StatDBEntry *dbentry;
+	PgStat_StatToastEntry *toastentry;
+	int			i;
+	bool		found;
+
+	dbentry = pgstat_get_db_entry(msg->m_databaseid, true);
+
+	/*
+	 * Process all TOAST entries in the message.
+	 */
+	for (i = 0; i < msg->m_nentries; i++, toastmsg++)
+	{
+		toastentry = (PgStat_StatToastEntry *) hash_search(dbentry->toastactivity,
+														 (void *) &(toastmsg->attr),
+														 HASH_ENTER, &found);
+
+		if (!found)
+		{
+			/*
+			 * If it's a new entry, initialize counters to the values
+			 * we just got.
+			 */
+			toastentry->t_numexternalized = toastmsg->t_numexternalized;
+			toastentry->t_numcompressed = toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess = toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_orig = toastmsg->t_size_orig;
+			toastentry->t_size_compressed = toastmsg->t_size_compressed;
+			toastentry->t_comp_time = toastmsg->t_comp_time;
+		}
+		else
+		{
+			/*
+			 * Otherwise add the values to the existing entry.
+			 */
+			toastentry->t_numexternalized += toastmsg->t_numexternalized;
+			toastentry->t_numcompressed += toastmsg->t_numcompressed;
+			toastentry->t_numcompressionsuccess += toastmsg->t_numcompressionsuccess;
+			toastentry->t_size_orig += toastmsg->t_size_orig;
+			toastentry->t_size_compressed += toastmsg->t_size_compressed;
+			toastentry->t_comp_time += toastmsg->t_comp_time;
+		}
+	}
+}
+
+/* ----------
+ *	Process a SUBSCRIPTIONDROP message.
  */
 static void
 pgstat_recv_subscription_drop(PgStat_MsgSubscriptionDrop *msg, int len)
diff --git a/src/backend/utils/activity/Makefile b/src/backend/utils/activity/Makefile
index 25a967ab7d..229cdaefd3 100644
--- a/src/backend/utils/activity/Makefile
+++ b/src/backend/utils/activity/Makefile
@@ -26,6 +26,7 @@ OBJS = \
 	pgstat_subscription.o \
 	pgstat_wal.o \
 	pgstat_slru.o \
+	pgstat_toast.o \
 	wait_event.o
 
 include $(top_srcdir)/src/backend/common.mk
diff --git a/src/backend/utils/activity/pgstat_toast.c b/src/backend/utils/activity/pgstat_toast.c
new file mode 100644
index 0000000000..b6ba62c302
--- /dev/null
+++ b/src/backend/utils/activity/pgstat_toast.c
@@ -0,0 +1,157 @@
+/* -------------------------------------------------------------------------
+ *
+ * pgstat_toast.c
+ *	  Implementation of TOAST statistics.
+ *
+ * This file contains the implementation of TOAST statistics. It is kept
+ * separate from pgstat.c to enforce the line between the statistics access /
+ * storage implementation and the details about individual types of
+ * statistics.
+ *
+ * Copyright (c) 2001-2022, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/activity/pgstat_toast.c
+ * -------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "utils/pgstat_internal.h"
+#include "utils/timestamp.h"
+
+/*
+ * Indicates if backend has some function stats that it hasn't yet
+ * sent to the collector.
+ */
+bool		have_toast_stats = false;
+
+/*
+ * Backends store per-toast-column info that's waiting to be sent to the collector
+ * in this hash table (indexed by column's PgStat_BackendAttrIdentifier).
+ */
+static HTAB *pgStatToastActions = NULL;
+
+/*
+ * Report TOAST activity
+ * Called by toast_helper functions.
+ */
+void
+pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							instr_time start_time)
+{
+	PgStat_BackendAttrIdentifier toastattr = { relid, attr };
+	PgStat_BackendToastEntry *htabent;
+	instr_time	time_spent;
+	bool		found;
+
+	if (pgStatSock == PGINVALID_SOCKET || !pgstat_track_toast)
+		return;
+
+	INSTR_TIME_SET_CURRENT(time_spent);
+	INSTR_TIME_SUBTRACT(time_spent, start_time);
+
+	if (!pgStatToastActions)
+	{
+		/* First time through - initialize toast stat table */
+		HASHCTL		hash_ctl;
+
+		hash_ctl.keysize = sizeof(PgStat_BackendAttrIdentifier);
+		hash_ctl.entrysize = sizeof(PgStat_BackendToastEntry);
+		pgStatToastActions = hash_create("TOAST stat entries",
+									  PGSTAT_TOAST_HASH_SIZE,
+									  &hash_ctl,
+									  HASH_ELEM | HASH_BLOBS);
+	}
+
+	/* Get the stats entry for this TOAST attribute, create if necessary */
+	htabent = hash_search(pgStatToastActions, &toastattr,
+						  HASH_ENTER, &found);
+	if (!found)
+	{
+		MemSet(&htabent->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	/* update counters */
+	if (externalized)
+	{
+		htabent->t_counts.t_numexternalized++;
+	}
+	if (compressed)
+	{
+		htabent->t_counts.t_numcompressed++;
+		htabent->t_counts.t_size_orig+=old_size;
+		if (new_size)
+		{
+			htabent->t_counts.t_numcompressionsuccess++;
+			htabent->t_counts.t_size_compressed+=new_size;
+		}
+	}
+	/* record time spent */
+	INSTR_TIME_ADD(htabent->t_counts.t_comp_time, time_spent);
+
+	/* indicate that we have something to send */
+	have_toast_stats = true;
+}
+
+/*
+ * Subroutine for pgstat_report_stat: populate and send a toast stat message
+ */
+void
+pgstat_send_toaststats(void)
+{
+	static const PgStat_ToastCounts all_zeroes;
+
+	PgStat_MsgToaststat msg;
+	PgStat_BackendToastEntry *entry;
+	HASH_SEQ_STATUS tstat;
+
+	if (pgStatToastActions == NULL)
+		return;
+
+	pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_TOASTSTAT);
+	msg.m_databaseid = MyDatabaseId;
+	msg.m_nentries = 0;
+
+	hash_seq_init(&tstat, pgStatToastActions);
+	while ((entry = (PgStat_BackendToastEntry *) hash_seq_search(&tstat)) != NULL)
+	{
+		PgStat_ToastEntry *m_ent;
+
+		/* Skip it if no counts accumulated since last time */
+		if (memcmp(&entry->t_counts, &all_zeroes,
+				   sizeof(PgStat_ToastCounts)) == 0)
+			continue;
+
+		/* need to convert format of time accumulators */
+		m_ent = &msg.m_entry[msg.m_nentries];
+		m_ent->attr = entry->attr;
+		m_ent->t_numexternalized = entry->t_counts.t_numexternalized;
+		m_ent->t_numcompressed = entry->t_counts.t_numcompressed;
+		m_ent->t_numcompressionsuccess = entry->t_counts.t_numcompressionsuccess;
+		m_ent->t_size_orig = entry->t_counts.t_size_orig;
+		m_ent->t_size_compressed = entry->t_counts.t_size_compressed;
+		m_ent->t_comp_time = INSTR_TIME_GET_MICROSEC(entry->t_counts.t_comp_time);
+
+		if (++msg.m_nentries >= PGSTAT_NUM_TOASTENTRIES)
+		{
+			pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+						msg.m_nentries * sizeof(PgStat_ToastEntry));
+			msg.m_nentries = 0;
+		}
+
+		/* reset the entry's counts */
+		MemSet(&entry->t_counts, 0, sizeof(PgStat_ToastCounts));
+	}
+
+	if (msg.m_nentries > 0)
+		pgstat_send(&msg, offsetof(PgStat_MsgToaststat, m_entry[0]) +
+					msg.m_nentries * sizeof(PgStat_ToastEntry));
+
+	have_toast_stats = false;
+}
+
diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c
index ce84525d40..a1f74c74ff 100644
--- a/src/backend/utils/adt/pgstatfuncs.c
+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -410,6 +410,78 @@ pg_stat_get_function_self_time(PG_FUNCTION_ARGS)
 	PG_RETURN_FLOAT8(((double) funcentry->f_self_time) / 1000.0);
 }
 
+Datum
+pg_stat_get_toast_externalizations(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numexternalized);
+}
+
+Datum
+pg_stat_get_toast_compressions(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressed);
+}
+
+Datum
+pg_stat_get_toast_compressionsuccesses(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_numcompressionsuccess);
+}
+
+Datum
+pg_stat_get_toast_originalsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_orig);
+}
+
+Datum
+pg_stat_get_toast_compressedsizesum(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_size_compressed);
+}
+
+Datum
+pg_stat_get_toast_total_time(PG_FUNCTION_ARGS)
+{
+	Oid			relid = PG_GETARG_OID(0);
+	int			attr = PG_GETARG_INT16(1);
+	PgStat_StatToastEntry *toastentry;
+
+	if ((toastentry = pgstat_fetch_stat_toastentry(relid,attr - 1)) == NULL)
+		PG_RETURN_NULL();
+	PG_RETURN_INT64(toastentry->t_comp_time);
+}
+
 Datum
 pg_stat_get_backend_idset(PG_FUNCTION_ARGS)
 {
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 9e8ab1420d..339d2553d4 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -1557,6 +1557,15 @@ static struct config_bool ConfigureNamesBool[] =
 		true,
 		NULL, NULL, NULL
 	},
+	{
+		{"track_toast", PGC_SUSET, STATS_COLLECTOR,
+			gettext_noop("Collects statistics on TOAST activity."),
+			NULL
+		},
+		&pgstat_track_toast,
+		false,
+		NULL, NULL, NULL
+	},
 	{
 		{"track_io_timing", PGC_SUSET, STATS_COLLECTOR,
 			gettext_noop("Collects timing statistics for database I/O activity."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 93d221a37b..4c3b7ae29b 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -613,6 +613,7 @@
 #track_io_timing = off
 #track_wal_io_timing = off
 #track_functions = none			# none, pl, all
+#track_toast = off
 #stats_temp_directory = 'pg_stat_tmp'
 
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 25304430f4..6d7ba55293 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5673,6 +5673,31 @@
   proparallel => 'r', prorettype => 'float8', proargtypes => 'oid',
   prosrc => 'pg_stat_get_function_self_time' },
 
+{ oid => '9700', descr => 'statistics: number of TOAST externalizations',
+  proname => 'pg_stat_get_toast_externalizations', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_externalizations' },
+{ oid => '9701', descr => 'statistics: number of TOAST compressions',
+  proname => 'pg_stat_get_toast_compressions', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressions' },
+  { oid => '9702', descr => 'statistics: number of successful TOAST compressions',
+  proname => 'pg_stat_get_toast_compressionsuccesses', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressionsuccesses' },
+{ oid => '9703', descr => 'statistics: total original size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_originalsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_originalsizesum' },
+{ oid => '9704', descr => 'statistics: total compressed size of compressed TOAST data',
+  proname => 'pg_stat_get_toast_compressedsizesum', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_compressedsizesum' },
+{ oid => '9705', descr => 'statistics: total time spend TOASTing data',
+  proname => 'pg_stat_get_toast_total_time', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => 'oid int4',
+  prosrc => 'pg_stat_get_toast_total_time' },
+
 { oid => '3037',
   descr => 'statistics: number of scans done for table/index in current transaction',
   proname => 'pg_stat_get_xact_numscans', provolatile => 'v',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 3584078f6e..c37d177d12 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -252,6 +252,7 @@ typedef enum StatMsgType
 	PGSTAT_MTYPE_DISCONNECT,
 	PGSTAT_MTYPE_SUBSCRIPTIONDROP,
 	PGSTAT_MTYPE_SUBSCRIPTIONERROR,
+	PGSTAT_MTYPE_TOASTSTAT,
 } StatMsgType;
 
 /* ----------
@@ -726,6 +727,80 @@ typedef struct PgStat_MsgDisconnect
 	SessionEndType m_cause;
 } PgStat_MsgDisconnect;
 
+/* ----------
+ * PgStat_BackendAttrIdentifier	Identifier for a single attribute/column (OID + attr)
+ * Used as a hashable identifier for (e.g.) TOAST columns
+ * ----------
+ */
+typedef struct PgStat_BackendAttrIdentifier
+{
+	Oid			relid;
+	int			attr;
+} PgStat_BackendAttrIdentifier;
+
+/* ----------
+ * PgStat_ToastCounts	The actual per-TOAST counts kept by a backend
+ *
+ * This struct should contain only actual event counters, because we memcmp
+ * it against zeroes to detect whether there are any counts to transmit.
+ *
+ * Note that the time counters are in instr_time format here.  We convert to
+ * microseconds in PgStat_Counter format when transmitting to the collector.
+ * ----------
+ */
+typedef struct PgStat_ToastCounts
+{
+	PgStat_Counter	t_numexternalized;
+	PgStat_Counter	t_numcompressed;
+	PgStat_Counter	t_numcompressionsuccess;
+	uint64		t_size_orig;
+	uint64		t_size_compressed;
+	instr_time	t_comp_time;
+} PgStat_ToastCounts;
+
+/* ----------
+ * PgStat_BackendToastEntry	Entry in backend's per-toast-attr hash table
+ * ----------
+ */
+typedef struct PgStat_BackendToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_ToastCounts 		t_counts;
+} PgStat_BackendToastEntry;
+
+/* ----------
+ * PgStat_ToastEntry			Per-TOAST-column info in a MsgToaststat
+ * ----------
+ */
+typedef struct PgStat_ToastEntry
+{
+	PgStat_BackendAttrIdentifier	attr;
+	PgStat_Counter 			t_numexternalized;
+	PgStat_Counter 			t_numcompressed;
+	PgStat_Counter 			t_numcompressionsuccess;
+	uint64		   		t_size_orig;
+	uint64		   		t_size_compressed;
+	PgStat_Counter			t_comp_time;	/* time in microseconds */
+} PgStat_ToastEntry;
+
+/* ----------
+ * PgStat_MsgToaststat			Sent by the backend to report function
+ *								usage statistics.
+ * ----------
+ */
+#define PGSTAT_NUM_TOASTENTRIES	\
+	((PGSTAT_MSG_PAYLOAD - sizeof(Oid) - sizeof(int))  \
+	 / sizeof(PgStat_ToastEntry))
+
+typedef struct PgStat_MsgToaststat
+{
+	PgStat_MsgHdr m_hdr;
+	Oid			m_databaseid;
+	int			m_nentries;
+	PgStat_ToastEntry m_entry[PGSTAT_NUM_TOASTENTRIES];
+} PgStat_MsgToaststat;
+
+
 /* ----------
  * PgStat_Msg					Union over all possible messages.
  * ----------
@@ -754,6 +829,7 @@ typedef union PgStat_Msg
 	PgStat_MsgSLRU msg_slru;
 	PgStat_MsgFuncstat msg_funcstat;
 	PgStat_MsgFuncpurge msg_funcpurge;
+	PgStat_MsgToaststat msg_toaststat;
 	PgStat_MsgRecoveryConflict msg_recoveryconflict;
 	PgStat_MsgDeadlock msg_deadlock;
 	PgStat_MsgTempFile msg_tempfile;
@@ -851,6 +927,7 @@ typedef struct PgStat_StatDBEntry
 	 */
 	HTAB	   *tables;
 	HTAB	   *functions;
+	HTAB	   *toastactivity;
 } PgStat_StatDBEntry;
 
 typedef struct PgStat_StatFuncEntry
@@ -906,6 +983,17 @@ typedef struct PgStat_StatSubEntry
 	TimestampTz stat_reset_timestamp;
 } PgStat_StatSubEntry;
 
+typedef struct PgStat_StatToastEntry
+{
+	PgStat_BackendAttrIdentifier t_id;
+	PgStat_Counter t_numexternalized;
+	PgStat_Counter t_numcompressed;
+	PgStat_Counter t_numcompressionsuccess;
+	uint64		   t_size_orig;
+	uint64		   t_size_compressed;
+	PgStat_Counter t_comp_time;	/* time in microseconds */
+} PgStat_StatToastEntry;
+
 typedef struct PgStat_StatTabEntry
 {
 	Oid			tableid;
@@ -991,6 +1079,7 @@ extern PgStat_BgWriterStats *pgstat_fetch_stat_bgwriter(void);
 extern PgStat_CheckpointerStats *pgstat_fetch_stat_checkpointer(void);
 extern PgStat_StatDBEntry *pgstat_fetch_stat_dbentry(Oid dbid);
 extern PgStat_StatFuncEntry *pgstat_fetch_stat_funcentry(Oid funcid);
+extern PgStat_StatToastEntry *pgstat_fetch_stat_toastentry(Oid rel_id, int attr);
 extern PgStat_GlobalStats *pgstat_fetch_global(void);
 extern PgStat_StatReplSlotEntry *pgstat_fetch_replslot(NameData slotname);
 extern PgStat_StatSubEntry *pgstat_fetch_stat_subscription(Oid subid);
@@ -1163,6 +1252,17 @@ extern void pgstat_report_subscription_drop(Oid subid);
 
 extern void pgstat_send_wal(bool force);
 
+/*
+ * Functions in pgstat_toast.c
+ */
+
+extern void pgstat_send_toaststats(void);
+extern void pgstat_report_toast_activity(Oid relid, int attr,
+							bool externalized,
+							bool compressed,
+							int32 old_size,
+							int32 new_size,
+							instr_time start_time);
 
 /*
  * Variables in pgstat.c
@@ -1171,6 +1271,7 @@ extern void pgstat_send_wal(bool force);
 /* GUC parameters */
 extern PGDLLIMPORT bool pgstat_track_counts;
 extern PGDLLIMPORT int pgstat_track_functions;
+extern PGDLLIMPORT bool pgstat_track_toast;
 extern char *pgstat_stat_directory;
 extern char *pgstat_stat_tmpname;
 extern char *pgstat_stat_filename;
diff --git a/src/include/utils/pgstat_internal.h b/src/include/utils/pgstat_internal.h
index abbb4f8d96..44b0aeb7af 100644
--- a/src/include/utils/pgstat_internal.h
+++ b/src/include/utils/pgstat_internal.h
@@ -27,6 +27,7 @@
 #define PGSTAT_DB_HASH_SIZE		16
 #define PGSTAT_TAB_HASH_SIZE	512
 #define PGSTAT_FUNCTION_HASH_SIZE	512
+#define PGSTAT_TOAST_HASH_SIZE	64
 #define PGSTAT_SUBSCRIPTION_HASH_SIZE	32
 #define PGSTAT_REPLSLOT_HASH_SIZE	32
 
diff --git a/src/test/regress/expected/rules.out b/src/test/regress/expected/rules.out
index 423b9b99fb..91358a5b62 100644
--- a/src/test/regress/expected/rules.out
+++ b/src/test/regress/expected/rules.out
@@ -2128,6 +2128,23 @@ pg_stat_sys_tables| SELECT pg_stat_all_tables.relid,
     pg_stat_all_tables.autoanalyze_count
    FROM pg_stat_all_tables
   WHERE ((pg_stat_all_tables.schemaname = ANY (ARRAY['pg_catalog'::name, 'information_schema'::name])) OR (pg_stat_all_tables.schemaname ~ '^pg_toast'::text));
+pg_stat_toast| SELECT n.nspname AS schemaname,
+    a.attrelid AS reloid,
+    a.attnum,
+    c.relname,
+    a.attname,
+    a.attstorage AS storagemethod,
+    pg_stat_get_toast_externalizations(a.attrelid, (a.attnum)::integer) AS externalized,
+    a.attcompression AS compressmethod,
+    pg_stat_get_toast_compressions(a.attrelid, (a.attnum)::integer) AS compressattempts,
+    pg_stat_get_toast_compressionsuccesses(a.attrelid, (a.attnum)::integer) AS compresssuccesses,
+    pg_stat_get_toast_compressedsizesum(a.attrelid, (a.attnum)::integer) AS compressedsize,
+    pg_stat_get_toast_originalsizesum(a.attrelid, (a.attnum)::integer) AS originalsize,
+    pg_stat_get_toast_total_time(a.attrelid, (a.attnum)::integer) AS total_time
+   FROM ((pg_attribute a
+     JOIN pg_class c ON ((c.oid = a.attrelid)))
+     LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace)))
+  WHERE (pg_stat_get_toast_externalizations(a.attrelid, (a.attnum)::integer) IS NOT NULL);
 pg_stat_user_functions| SELECT p.oid AS funcid,
     n.nspname AS schemaname,
     p.proname AS funcname,
diff --git a/src/test/regress/expected/stats.out b/src/test/regress/expected/stats.out
index 06a1d2f229..b9514e1f34 100644
--- a/src/test/regress/expected/stats.out
+++ b/src/test/regress/expected/stats.out
@@ -11,6 +11,32 @@ SHOW track_counts;  -- must be on
  on
 (1 row)
 
+-- prepare and fill the pg_stat_toast table now:
+SHOW track_toast;
+ track_toast 
+-------------
+ off
+(1 row)
+
+SET track_toast TO on;
+SHOW track_toast;
+ track_toast 
+-------------
+ on
+(1 row)
+
+TABLE pg_stat_toast; -- view exists
+ schemaname | reloid | attnum | relname | attname | storagemethod | externalized | compressmethod | compressattempts | compresssuccesses | compressedsize | originalsize | total_time 
+------------+--------+--------+---------+---------+---------------+--------------+----------------+------------------+-------------------+----------------+--------------+------------
+(0 rows)
+
+CREATE TABLE toast_test (cola TEXT, colb TEXT, colc TEXT , cold TEXT);
+ALTER TABLE toast_test ALTER colb SET STORAGE EXTERNAL;
+ALTER TABLE toast_test ALTER colc SET STORAGE MAIN;
+ALTER TABLE toast_test ALTER cold SET STORAGE PLAIN;
+INSERT INTO toast_test VALUES (repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100) );
+-- make sure we don't interfere with the other tests:
+SET track_toast TO off;
 -- ensure that both seqscan and indexscan plans are allowed
 SET enable_seqscan TO on;
 SET enable_indexscan TO on;
@@ -255,6 +281,42 @@ SELECT pg_stat_get_tuples_hot_updated('brin_hot'::regclass::oid);
 
 DROP TABLE brin_hot;
 DROP FUNCTION wait_for_hot_stats();
+-- now check that the track_toast stuff worked:
+SELECT attname
+	,storagemethod
+	,externalized
+	,compressmethod
+	,compressattempts
+	,compresssuccesses
+	,compressedsize < originalsize AS compression_works
+	, total_time > 0 AS takes_time
+FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY attname;
+ attname | storagemethod | externalized | compressmethod | compressattempts | compresssuccesses | compression_works | takes_time 
+---------+---------------+--------------+----------------+------------------+-------------------+-------------------+------------
+ cola    | x             |            1 |                |                1 |                 1 | t                 | t
+ colb    | e             |            1 |                |                0 |                 0 | f                 | t
+ colc    | m             |            0 |                |                1 |                 1 | t                 | t
+(3 rows)
+
+SELECT compressattempts=0 AS external_doesnt_compress FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'e';
+ external_doesnt_compress 
+--------------------------
+ t
+(1 row)
+
+SELECT externalized=0 AS main_doesnt_externalize FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'm';
+ main_doesnt_externalize 
+-------------------------
+ t
+(1 row)
+
+DROP TABLE toast_test;
+SELECT count(*) FROM pg_stat_toast WHERE relname = 'toast_test';
+ count 
+-------
+     0
+(1 row)
+
 -- ensure that stats accessors handle NULL input correctly
 SELECT pg_stat_get_replication_slot(NULL);
  pg_stat_get_replication_slot 
diff --git a/src/test/regress/sql/stats.sql b/src/test/regress/sql/stats.sql
index ae1ec173e3..b30de2fa7a 100644
--- a/src/test/regress/sql/stats.sql
+++ b/src/test/regress/sql/stats.sql
@@ -8,6 +8,20 @@
 -- conditio sine qua non
 SHOW track_counts;  -- must be on
 
+-- prepare and fill the pg_stat_toast table now:
+SHOW track_toast;
+SET track_toast TO on;
+SHOW track_toast;
+TABLE pg_stat_toast; -- view exists
+
+CREATE TABLE toast_test (cola TEXT, colb TEXT, colc TEXT , cold TEXT);
+ALTER TABLE toast_test ALTER colb SET STORAGE EXTERNAL;
+ALTER TABLE toast_test ALTER colc SET STORAGE MAIN;
+ALTER TABLE toast_test ALTER cold SET STORAGE PLAIN;
+INSERT INTO toast_test VALUES (repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100), repeat(md5('a'),100) );
+-- make sure we don't interfere with the other tests:
+SET track_toast TO off;
+
 -- ensure that both seqscan and indexscan plans are allowed
 SET enable_seqscan TO on;
 SET enable_indexscan TO on;
@@ -228,6 +242,20 @@ SELECT pg_stat_get_tuples_hot_updated('brin_hot'::regclass::oid);
 DROP TABLE brin_hot;
 DROP FUNCTION wait_for_hot_stats();
 
+-- now check that the track_toast stuff worked:
+SELECT attname
+	,storagemethod
+	,externalized
+	,compressmethod
+	,compressattempts
+	,compresssuccesses
+	,compressedsize < originalsize AS compression_works
+	, total_time > 0 AS takes_time
+FROM pg_stat_toast WHERE relname = 'toast_test' ORDER BY attname;
+SELECT compressattempts=0 AS external_doesnt_compress FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'e';
+SELECT externalized=0 AS main_doesnt_externalize FROM pg_stat_toast WHERE relname = 'toast_test' AND storagemethod = 'm';
+DROP TABLE toast_test;
+SELECT count(*) FROM pg_stat_toast WHERE relname = 'toast_test';
 
 -- ensure that stats accessors handle NULL input correctly
 SELECT pg_stat_get_replication_slot(NULL);