add comments in stateless test
@@ -11,7 +11,8 @@ insert into t values (7);
-- expects 3 history items
select count(*) from fuse_history('db_09_0007', 't');
--- truncate table will remove all the historical data but the latest one
+-- truncate table will remove all the historical data but the latest snapshot
+-- only the latest snapshot will be ketp, no segments or block, but unfortunately, we can not verify it by sql (yet)
truncate table 't';
-- expect 1 snapshot left
select count(*) from fuse_history('db_09_0007', 't');
