diff --git a/src/backend/access/heap/pruneheap.c b/src/backend/access/heap/pruneheap.c
index 6ff9251..bad6bbf 100644
--- a/src/backend/access/heap/pruneheap.c
+++ b/src/backend/access/heap/pruneheap.c
@@ -99,10 +99,18 @@ heap_page_prune_opt(Relation relation, Buffer buffer)
 	 * consumed between this point and acquiring the lock).  This allows us to
 	 * save significant overhead in the case where the page is found not to be
 	 * prunable.
+	 *
+	 * We don't allow early pruning for a TOAST relation because the dangling
+	 * pointer from a heap tuple which might still be visible to someone could
+	 * cause problems.   XXX: Since update of TOAST values is not allowed is
+	 * there really sufficient benefit for pruning TOAST pages at all?  Should
+	 * we simply return for a TOAST relation?
 	 */
 	if (IsCatalogRelation(relation) ||
 		RelationIsAccessibleInLogicalDecoding(relation))
 		OldestXmin = RecentGlobalXmin;
+	else if (IsToastRelation(relation))
+		OldestXmin = RecentGlobalDataXmin;
 	else
 		OldestXmin =
 			TransactionIdLimitedForOldSnapshots(RecentGlobalDataXmin,
diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c
index 43bbd90..2351d84 100644
--- a/src/backend/commands/cluster.c
+++ b/src/backend/commands/cluster.c
@@ -852,7 +852,7 @@ copy_heap_data(Oid OIDNewHeap, Oid OIDOldHeap, Oid OIDOldIndex, bool verbose,
 	 */
 	vacuum_set_xid_limits(OldHeap, 0, 0, 0, 0,
 						  &OldestXmin, &FreezeXid, NULL, &MultiXactCutoff,
-						  NULL);
+						  NULL, false);
 
 	/*
 	 * FreezeXid will become the table's new relfrozenxid, and that mustn't go
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 0563e63..453a1bc 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -72,7 +72,7 @@ static void vac_truncate_clog(TransactionId frozenXID,
 				  TransactionId lastSaneFrozenXid,
 				  MultiXactId lastSaneMinMulti);
 static bool vacuum_rel(Oid relid, RangeVar *relation, int options,
-		   VacuumParams *params);
+		   VacuumParams *params, bool toastRecursion);
 
 /*
  * Primary entry point for manual VACUUM and ANALYZE commands
@@ -302,7 +302,7 @@ vacuum(int options, RangeVar *relation, Oid relid, VacuumParams *params,
 
 			if (options & VACOPT_VACUUM)
 			{
-				if (!vacuum_rel(relid, relation, options, params))
+				if (!vacuum_rel(relid, relation, options, params, false))
 					continue;
 			}
 
@@ -479,11 +479,13 @@ vacuum_set_xid_limits(Relation rel,
 					  TransactionId *freezeLimit,
 					  TransactionId *xidFullScanLimit,
 					  MultiXactId *multiXactCutoff,
-					  MultiXactId *mxactFullScanLimit)
+					  MultiXactId *mxactFullScanLimit,
+					  bool noOldestXminAdjustment)
 {
 	int			freezemin;
 	int			mxid_freezemin;
 	int			effective_multixact_freeze_max_age;
+	TransactionId xmin;
 	TransactionId limit;
 	TransactionId safeLimit;
 	MultiXactId mxactLimit;
@@ -498,8 +500,12 @@ vacuum_set_xid_limits(Relation rel,
 	 * working on a particular table at any time, and that each vacuum is
 	 * always an independent transaction.
 	 */
-	*oldestXmin =
-		TransactionIdLimitedForOldSnapshots(GetOldestXmin(rel, true), rel);
+
+	xmin = GetOldestXmin(rel, true);
+	if (noOldestXminAdjustment)
+		*oldestXmin = xmin;
+	else
+		*oldestXmin = TransactionIdLimitedForOldSnapshots(xmin, rel);
 
 	Assert(TransactionIdIsNormal(*oldestXmin));
 
@@ -1182,10 +1188,21 @@ vac_truncate_clog(TransactionId frozenXID,
  *		many small transactions.  Otherwise, two-phase locking would require
  *		us to lock the entire database during one pass of the vacuum cleaner.
  *
+ *		When old_snapshot_threshold is allowing early pruning/vacuuming, care
+ *		must be taken with cleanup of TOAST relations.  While they normally
+ *		can be pruned or vacuumed independently of the owning heap, and MVCC
+ *		visibility rules will keep things safe, the heap must be cleaned up
+ *		before its related TOAST relation to keep things safe.  Since a vacuum
+ *		of a heap causes a recursive call here to also vacuumm TOAST data,
+ *		pass along a parameter to show when this is done, so the oldestXmin
+ *		so we can allow the oldestXmin adjustment for TOAST vacuum only when
+ *		it is safe.
+ *
  *		At entry and exit, we are not inside a transaction.
  */
 static bool
-vacuum_rel(Oid relid, RangeVar *relation, int options, VacuumParams *params)
+vacuum_rel(Oid relid, RangeVar *relation, int options, VacuumParams *params,
+		   bool toastRecursion)
 {
 	LOCKMODE	lmode;
 	Relation	onerel;
@@ -1390,7 +1407,8 @@ vacuum_rel(Oid relid, RangeVar *relation, int options, VacuumParams *params)
 					(options & VACOPT_VERBOSE) != 0);
 	}
 	else
-		lazy_vacuum_rel(onerel, options, params, vac_strategy);
+		lazy_vacuum_rel(onerel, options, params, vac_strategy,
+						toastRecursion ? false : IsToastRelation(onerel));
 
 	/* Roll back any GUC changes executed by index functions */
 	AtEOXact_GUC(false, save_nestlevel);
@@ -1416,7 +1434,7 @@ vacuum_rel(Oid relid, RangeVar *relation, int options, VacuumParams *params)
 	 * totally unimportant for toast relations.
 	 */
 	if (toast_relid != InvalidOid)
-		vacuum_rel(toast_relid, relation, options, params);
+		vacuum_rel(toast_relid, relation, options, params, true);
 
 	/*
 	 * Now release the session-level lock on the master table.
diff --git a/src/backend/commands/vacuumlazy.c b/src/backend/commands/vacuumlazy.c
index 32b6fdd..f24dbfa 100644
--- a/src/backend/commands/vacuumlazy.c
+++ b/src/backend/commands/vacuumlazy.c
@@ -174,7 +174,7 @@ static bool heap_page_is_all_visible(Relation rel, Buffer buf,
  */
 void
 lazy_vacuum_rel(Relation onerel, int options, VacuumParams *params,
-				BufferAccessStrategy bstrategy)
+				BufferAccessStrategy bstrategy, bool noOldestXminAdjustment)
 {
 	LVRelStats *vacrelstats;
 	Relation   *Irel;
@@ -221,7 +221,8 @@ lazy_vacuum_rel(Relation onerel, int options, VacuumParams *params,
 						  params->multixact_freeze_min_age,
 						  params->multixact_freeze_table_age,
 						  &OldestXmin, &FreezeLimit, &xidFullScanLimit,
-						  &MultiXactCutoff, &mxactFullScanLimit);
+						  &MultiXactCutoff, &mxactFullScanLimit,
+						  noOldestXminAdjustment);
 
 	/*
 	 * We request an aggressive scan if the table's frozen Xid is now older
diff --git a/src/include/commands/vacuum.h b/src/include/commands/vacuum.h
index 80cd4a8..ca76db6 100644
--- a/src/include/commands/vacuum.h
+++ b/src/include/commands/vacuum.h
@@ -184,13 +184,15 @@ extern void vacuum_set_xid_limits(Relation rel,
 					  TransactionId *freezeLimit,
 					  TransactionId *xidFullScanLimit,
 					  MultiXactId *multiXactCutoff,
-					  MultiXactId *mxactFullScanLimit);
+					  MultiXactId *mxactFullScanLimit,
+					  bool noOldestXminAdjustment);
 extern void vac_update_datfrozenxid(void);
 extern void vacuum_delay_point(void);
 
 /* in commands/vacuumlazy.c */
 extern void lazy_vacuum_rel(Relation onerel, int options,
-				VacuumParams *params, BufferAccessStrategy bstrategy);
+				VacuumParams *params, BufferAccessStrategy bstrategy,
+				bool noOldestXminAdjustment);
 
 /* in commands/analyze.c */
 extern void analyze_rel(Oid relid, RangeVar *relation, int options,