explain format='hint' doesn't work for IndexHashJoin / IndexMergeJoin

[eurekaka]

Development Task

mysql> create table t1(a int, b int, c int, key(b), key(c));
Query OK, 0 rows affected (0.01 sec)

mysql> create table t2 like t1;
Query OK, 0 rows affected (0.00 sec)

mysql> explain format='hint' select /*+ inl_merge_join(t2) */ * from t1 inner join t2 on t1.b = t2.b and t1.c = 1;
+--------------------------------------------------------------------------------------------+
| hint                                                                                       |
+--------------------------------------------------------------------------------------------+
| use_index(@`sel_1` `test`.`t1` `c`), use_index(@`sel_1` `test`.`t2` `b`), inl_merge_join() |
+--------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> explain format='hint' select /*+ inl_hash_join(t2) */ * from t1 inner join t2 on t1.b = t2.b and t1.c = 1;
+---------------------------------------------------------------------------------------------------------------------+
| hint                                                                                                                |
+---------------------------------------------------------------------------------------------------------------------+
| use_index(@`sel_1` `test`.`t1` `c`), use_index(@`sel_1` `test`.`t2` `b`), inl_hash_join(@`sel_1` ), inl_hash_join() |
+---------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

The generated inl_hash_join() / inl_merge_join() hint would not take effect since they have no table parameters.

[ti-srebot]

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