Im wondering if someone could help me understand this. If you look at my two queries below. By the ORDER BY one is using ` and the other ', as a result, if you do an explain you will see that the top query does a filesort, while the other does not.
Would anyone know why.
mysql> explain SELECT `Contact`.`id`, `Contact`.`name`, `Contact`.`surname`, `Contact`.`mobile`, `Contact`.`user_id`, `Contact`.`active`, `Contact`.`created` FROM `contacts` AS `Contact` WHERE `Contact`.`user_id` = 10203 AND `Contact`.`active` = '1' ORDER BY `name` asc LIMIT 10; +----+-------------+---------+------+---------------+------+---------+------+--------+-----------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+---------+------+---------------+------+---------+------+--------+-----------------------------+ | 1 | SIMPLE | Contact | ALL | NULL | NULL | NULL | NULL | 344709 | Using where; Using filesort | +----+-------------+---------+------+---------------+------+---------+------+--------+-----------------------------+ 1 row in set (0.00 sec)
mysql> explain SELECT `Contact`.`id`, `Contact`.`name`, `Contact`.`surname`, `Contact`.`mobile`, `Contact`.`user_id`, `Contact`.`active`, `Contact`.`created` FROM `contacts` AS `Contact` WHERE `Contact`.`user_id` = 10203 AND `Contact`.`active` = '1' ORDER BY 'name' asc LIMIT 10; +----+-------------+---------+------+---------------+------+---------+------+--------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+---------+------+---------------+------+---------+------+--------+-------------+ | 1 | SIMPLE | Contact | ALL | NULL | NULL | NULL | NULL | 344710 | Using where | +----+-------------+---------+------+---------------+------+---------+------+--------+-------------+ 1 row in set (0.00 sec)
Thanks Brent
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Mar 30
Simcha Younger Re: ` vs '
Mar 30, 2011; 10:23
Simcha Younger
Re: ` vs '
Mar 30
Mark Goodge Re: ` vs '
Mar 30, 2011; 09:39
Mark Goodge
Re: ` vs '
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