Fix: initialize entry->snapname to NULL.

And free tupleDesc and close table on commit transcation.

src/backend/commands/matview.c

@@ -3301,19 +3301,6 @@ clean_up_IVM_hash_entry(MV_TriggerHashEntry *entry, bool is_abort)
 			list_free(table->new_tuplestores);
 			table->new_tuplestores = NIL;
 		}
-		if (!is_abort)
-		{
-			if (table->slot)
-			{
-				ExecDropSingleTupleTableSlot(table->slot);
-				table->slot = NULL;
-			}
-			if (table->rel)
-			{
-				table_close(table->rel, NoLock);
-				table->rel = NULL;
-			}
-		}
 	}
 
 	if (entry->tables)
@@ -3482,6 +3469,7 @@ AddPreassignedMVEntry(Oid matview_id, Oid table_id, const char* snapname)
 		entry->has_new = false;
 		entry->pid = MyProcPid;
 		entry->snapshot = NULL;
+		entry->snapname = NULL;
 	}
 
 	/* Switch to the new resource owner and memory context */