> Den 27/10/2014 kl. 13.20 skrev Collin Anderson <cmawebs...@gmail.com>:
>
> mysql> explain SELECT COUNT(*)
> -> FROM `order_order`
> -> WHERE `order_order`.`status` != 4
> -> AND (`order_order`.`user_id` = 12345 OR `order_order`.`account_number`
> -> = 123456);
> +----+-------------+-------------+------+-------------------------------------------------------------------------------------+------+---------+------+--------+-------------+
> | id | select_type | table | type | possible_keys
> | key | key_len | ref |
> rows | Extra |
> +----+-------------+-------------+------+-------------------------------------------------------------------------------------+------+---------+------+--------+-------------+
> | 1 | SIMPLE | order_order | ALL |
> order_order_fbfc09f1,order_order_979d4f1e,order_order_48fb58bb,order_order_309e75c7
> | NULL | NULL | NULL | 338275 | Using where |
> +----+-------------+-------------+------+-------------------------------------------------------------------------------------+------+---------+------+--------+-------------+
> 1 row in set (0.16 sec)
>
> I can't get it to use the indexes when I have the "status" clause.
Note that your indexes are on individual columns, not combined. So MySQL has to
choose one of the indexes; it can't combine them. It's probably choosing the
state index, then deciding that the cardinality is very low (or stats show that
state=4 is true for more than n pct of the rows) and then does a full table
scan.
You might benefit from adding combined indexes with status and
account_number|user.
class Meta:
index_together = [
['status', 'account_number'],
['status', 'user'],
]
Erik
--
You received this message because you are subscribed to the Google Groups
"Django users" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to django-users+unsubscr...@googlegroups.com.
To post to this group, send email to django-users@googlegroups.com.
Visit this group at http://groups.google.com/group/django-users.
To view this discussion on the web visit
https://groups.google.com/d/msgid/django-users/1B735AD7-8D31-4EE5-AB10-9B15AC443CE5%40cederstrand.dk.
For more options, visit https://groups.google.com/d/optout.
