5 files changed, 69 insertions, 1 deletions
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index 9ec8cda1c68..2be7f817c78 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -213,6 +213,27 @@ static const int MultiXactStatusLock[MaxMultiXactStatus + 1] =
 #define TUPLOCK_from_mxstatus(status) \
 			(MultiXactStatusLock[(status)])
 
+/*
+ * Check that we have a valid snapshot if we might need TOAST access.
+ */
+static inline void
+AssertHasSnapshotForToast(Relation rel)
+{
+#ifdef USE_ASSERT_CHECKING
+
+	/* bootstrap mode in particular breaks this rule */
+	if (!IsNormalProcessingMode())
+		return;
+
+	/* if the relation doesn't have a TOAST table, we are good */
+	if (!OidIsValid(rel->rd_rel->reltoastrelid))
+		return;
+
+	Assert(HaveRegisteredOrActiveSnapshot());
+
+#endif							/* USE_ASSERT_CHECKING */
+}
+
 /* ----------------------------------------------------------------
  *						 heap support routines
  * ----------------------------------------------------------------
@@ -2066,6 +2087,8 @@ heap_insert(Relation relation, HeapTuple tup, CommandId cid,
 	Assert(HeapTupleHeaderGetNatts(tup->t_data) <=
 		   RelationGetNumberOfAttributes(relation));
 
+	AssertHasSnapshotForToast(relation);
+
 	/*
 	 * Fill in tuple header fields and toast the tuple if necessary.
 	 *
@@ -2343,6 +2366,8 @@ heap_multi_insert(Relation relation, TupleTableSlot **slots, int ntuples,
 	/* currently not needed (thus unsupported) for heap_multi_insert() */
 	Assert(!(options & HEAP_INSERT_NO_LOGICAL));
 
+	AssertHasSnapshotForToast(relation);
+
 	needwal = RelationNeedsWAL(relation);
 	saveFreeSpace = RelationGetTargetPageFreeSpace(relation,
 												   HEAP_DEFAULT_FILLFACTOR);
@@ -2765,6 +2790,8 @@ heap_delete(Relation relation, ItemPointer tid,
 
 	Assert(ItemPointerIsValid(tid));
 
+	AssertHasSnapshotForToast(relation);
+
 	/*
 	 * Forbid this during a parallel operation, lest it allocate a combo CID.
 	 * Other workers might need that combo CID for visibility checks, and we
@@ -3260,6 +3287,8 @@ heap_update(Relation relation, ItemPointer otid, HeapTuple newtup,
 	Assert(HeapTupleHeaderGetNatts(newtup->t_data) <=
 		   RelationGetNumberOfAttributes(relation));
 
+	AssertHasSnapshotForToast(relation);
+
 	/*
 	 * Forbid this during a parallel operation, lest it allocate a combo CID.
 	 * Other workers might need that combo CID for visibility checks, and we
diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index d962fe392cd..c3ec2076a52 100644
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -4226,7 +4226,7 @@ ReindexRelationConcurrently(const ReindexStmt *stmt, Oid relationOid, const Rein
 									 false);
 
 		/*
-		 * Updating pg_index might involve TOAST table access, so ensure we
+		 * Swapping the indexes might involve TOAST table access, so ensure we
 		 * have a valid snapshot.
 		 */
 		PushActiveSnapshot(GetTransactionSnapshot());
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 54ad38247aa..acf11e83c04 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -20964,9 +20964,17 @@ ATExecDetachPartition(List **wqueue, AlteredTableInfo *tab, Relation rel,
 		tab->rel = rel;
 	}
 
+	/*
+	 * Detaching the partition might involve TOAST table access, so ensure we
+	 * have a valid snapshot.
+	 */
+	PushActiveSnapshot(GetTransactionSnapshot());
+
 	/* Do the final part of detaching */
 	DetachPartitionFinalize(rel, partRel, concurrent, defaultPartOid);
 
+	PopActiveSnapshot();
+
 	ObjectAddressSet(address, RelationRelationId, RelationGetRelid(partRel));
 
 	/* keep our lock until commit */
diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index 981be42e3af..451fb90a610 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -2234,6 +2234,12 @@ do_autovacuum(void)
 						get_namespace_name(classForm->relnamespace),
 						NameStr(classForm->relname))));
 
+		/*
+		 * Deletion might involve TOAST table access, so ensure we have a
+		 * valid snapshot.
+		 */
+		PushActiveSnapshot(GetTransactionSnapshot());
+
 		object.classId = RelationRelationId;
 		object.objectId = relid;
 		object.objectSubId = 0;
@@ -2246,6 +2252,7 @@ do_autovacuum(void)
 		 * To commit the deletion, end current transaction and start a new
 		 * one.  Note this also releases the locks we took.
 		 */
+		PopActiveSnapshot();
 		CommitTransactionCommand();
 		StartTransactionCommand();
 
diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c
index 4151a4b2a96..a23262957ac 100644
--- a/src/backend/replication/logical/worker.c
+++ b/src/backend/replication/logical/worker.c
@@ -4626,8 +4626,16 @@ run_apply_worker()
 		walrcv_startstreaming(LogRepWorkerWalRcvConn, &options);
 
 		StartTransactionCommand();
+
+		/*
+		 * Updating pg_subscription might involve TOAST table access, so
+		 * ensure we have a valid snapshot.
+		 */
+		PushActiveSnapshot(GetTransactionSnapshot());
+
 		UpdateTwoPhaseState(MySubscription->oid, LOGICALREP_TWOPHASE_STATE_ENABLED);
 		MySubscription->twophasestate = LOGICALREP_TWOPHASE_STATE_ENABLED;
+		PopActiveSnapshot();
 		CommitTransactionCommand();
 	}
 	else
@@ -4843,7 +4851,15 @@ DisableSubscriptionAndExit(void)
 
 	/* Disable the subscription */
 	StartTransactionCommand();
+
+	/*
+	 * Updating pg_subscription might involve TOAST table access, so ensure we
+	 * have a valid snapshot.
+	 */
+	PushActiveSnapshot(GetTransactionSnapshot());
+
 	DisableSubscription(MySubscription->oid);
+	PopActiveSnapshot();
 	CommitTransactionCommand();
 
 	/* Ensure we remove no-longer-useful entry for worker's start time */
@@ -4948,6 +4964,12 @@ clear_subscription_skip_lsn(XLogRecPtr finish_lsn)
 	}
 
 	/*
+	 * Updating pg_subscription might involve TOAST table access, so ensure we
+	 * have a valid snapshot.
+	 */
+	PushActiveSnapshot(GetTransactionSnapshot());
+
+	/*
 	 * Protect subskiplsn of pg_subscription from being concurrently updated
 	 * while clearing it.
 	 */
@@ -5005,6 +5027,8 @@ clear_subscription_skip_lsn(XLogRecPtr finish_lsn)
 	heap_freetuple(tup);
 	table_close(rel, NoLock);
 
+	PopActiveSnapshot();
+
 	if (started_tx)
 		CommitTransactionCommand();
 }