SELECT INTO OUTFILE doesn't take effect when using clustered index to filter data

[pcqz]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

create table t (id int not null, primary key (id) /*T![clustered_index] CLUSTERED */ );
insert into t values(1);
select * from t where id=1 into outfile '/tmp/data.txt';

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

The resulting row is written to the file data.txt.

3. What did you see instead (Required)

The resulting row is just displayed in terminal.

4. What is your TiDB version? (Required)

v6.6.0

[yibin87]

Seems a planner issue:
mysql> explain select * from t where id=1 into outfile '/tmp/data.txt';
+-------------+---------+------+---------------+---------------+
| id | estRows | task | access object | operator info |
+-------------+---------+------+---------------+---------------+
| Point_Get_1 | 1.00 | root | table:t | handle:1 |
+-------------+---------+------+---------------+---------------+
1 row in set (0.00 sec)

[yibin87]

/remove-sig execution

[yibin87]

/sig planner