ticase 1247 fail

[time-and-fate]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

use test
drop table if exists t1;
drop table if exists t2;
create table t1(a int);
create table t2(a int);
insert into t1 values(null), (null), (null), (null);
insert into t2 values(null), (null);
analyze table t1;
analyze table t2;
explain select * from t2 left join t1 on t1.a=t2.a order by t1.a, t2.a;

2. What did you expect to see? (Required)

Build side of the Join is t1.

3. What did you see instead (Required)

Build side of the Join is t2.

4. What is your TiDB version? (Required)

master, release-6.0