no_join related hints don't work in sql binding #52813
Description
Bug Report
Please answer these questions before submitting your issue. Thanks!
1. Minimal reproduce step (Required)
use test;
create table a(id int key);
create table b(id int key);
create binding for select * from a, b where a.id=b.id using select /*+ no_merge_join(a,b) */ * from a, b where a.id=b.id;
show bindings;
explain select * from a, b where a.id=b.id;
In addition to no_merge_join, the other no_join hints like no_hash_join, no_index_join, no_index_hash_join, no_index_merge_join also have the same issue.
2. What did you expect to see? (Required)
The hint works in sql binding.
3. What did you see instead (Required)
mysql> show bindings;
+--------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------+------------+---------+-------------------------+-------------------------+---------+-----------------+--------+------------------------------------------------------------------+-------------+
| Original_sql | Bind_sql | Default_db | Status | Create_time | Update_time | Charset | Collation | Source | Sql_digest | Plan_digest |
+--------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------+------------+---------+-------------------------+-------------------------+---------+-----------------+--------+------------------------------------------------------------------+-------------+
| select * from ( `test` . `a` ) join `test` . `b` where `a` . `id` = `b` . `id` | SELECT /*+ no_merge_join()*/ * FROM (`test`.`a`) JOIN `test`.`b` WHERE `a`.`id` = `b`.`id` | test | enabled | 2024-04-22 20:25:43.628 | 2024-04-22 20:25:43.628 | utf8 | utf8_general_ci | manual | 0fcc6567db6b75418c703cc9f9f17c03125ca90730298b2edb8c9c1b81378e4e | |
+--------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------+------------+---------+-------------------------+-------------------------+---------+-----------------+--------+------------------------------------------------------------------+-------------+
1 row in set (0.00 sec)
mysql> explain select * from a, b where a.id=b.id;
+-----------------------------+----------+-----------+---------------+-----------------------------------------------------+
| id | estRows | task | access object | operator info |
+-----------------------------+----------+-----------+---------------+-----------------------------------------------------+
| MergeJoin_8 | 12500.00 | root | | inner join, left key:test.a.id, right key:test.b.id |
| ├─TableReader_32(Build) | 10000.00 | root | | data:TableFullScan_31 |
| │ └─TableFullScan_31 | 10000.00 | cop[tikv] | table:b | keep order:true, stats:pseudo |
| └─TableReader_30(Probe) | 10000.00 | root | | data:TableFullScan_29 |
| └─TableFullScan_29 | 10000.00 | cop[tikv] | table:a | keep order:true, stats:pseudo |
+-----------------------------+----------+-----------+---------------+-----------------------------------------------------+
5 rows in set, 1 warning (0.00 sec)
mysql> show warnings;
+---------+------+----------------------------------------------------------------------------------------+
| Level | Code | Message |
+---------+------+----------------------------------------------------------------------------------------+
| Warning | 1815 | Hint no_merge_join() is inapplicable. Please specify the table names in the arguments. |
+---------+------+----------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
4. What is your TiDB version? (Required)
v6.5.5