We can not use the string as the variable key to use in the hint.
Before this PR
mysql> SET enable_nereids_planner=true;
Query OK, 0 rows affected (0.01 sec)
mysql> set enable_fallback_to_original_planner=false;
Query OK, 0 rows affected (0.10 sec)
mysql> explain select /*+ SET_var("enable_nereids_planner" = "false") */ 1;
ERROR 1105 (HY000): Exception, msg: Nereids cannot parse the SQL, and fallback disabled. caused by:
no viable alternative at input 'select /*+ SET_var("enable_nereids_planner"'(line 1, pos 27)
After this PR
mysql> SET enable_nereids_planner=true;
Query OK, 0 rows affected (0.01 sec)
mysql> set enable_fallback_to_original_planner=false;
Query OK, 0 rows affected (0.10 sec)
mysql> select /*+ SET_var("enable_nereids_planner" = "false") */ 1;
+------+
| 1 |
+------+
| 1 |
+------+
1 row in set (0.00 sec)
Describe your changes.
Support the string for the hint key in the Parser.
d6c2ef4727