Bug #106623 Incorrect multi-index hint example
Submitted: 2 Mar 22:01 Modified: 3 Mar 22:17
Reporter: Matt Lord Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Server: Documentation Severity:S3 (Non-critical)
Version:8.0 OS:Any
Assigned to: Jon Stephens CPU Architecture:Any

[2 Mar 22:01] Matt Lord
Description:
The second to last example on this page uses an invalid syntax:
https://dev.mysql.com/doc/refman/8.0/en/index-hints.html :

mysql> SELECT * FROM t
    ->   USE INDEX (index1)
    ->   IGNORE INDEX (index1) FOR ORDER BY
    ->   IGNORE INDEX (index1) FOR GROUP BY;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'ORDER BY
  IGNORE INDEX (index1) FOR GROUP BY' at line 3

The index should come after the FOR clause (it is in other examples).

How to repeat:
mysql> create table t (id int primary key, ic varchar(100), key `index1` (ic));
Query OK, 0 rows affected (0.01 sec)

mysql> SELECT * FROM t   USE INDEX (index1)   IGNORE INDEX (index1) FOR ORDER BY   IGNORE INDEX (index1) FOR GROUP BY;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'ORDER BY   IGNORE INDEX (index1) FOR GROUP BY' at line 1

mysql> SELECT * FROM t   USE INDEX (index1)   IGNORE INDEX FOR ORDER BY (index1)   IGNORE INDEX FOR GROUP BY (index1);
Empty set (0.00 sec)

Suggested fix:
I think you can guess. :-D
[3 Mar 4:59] MySQL Verification Team
Hello Matt,

Thank you for the bug report.

Sincerely,
Umesh
[3 Mar 22:17] Jon Stephens
Hi, Matt! Thanks for spotting this.

Fixed in the 5.6, 5.7, 8.0 editions of the Manual, in mysqldoc rev 72167.

Closed.