Hi! On Thu, Jun 12, 2014 at 1:36 PM, Antonio Fernández Pérez <antoniofernan...@fabergames.com> wrote:
> Hi Lay, > > If I don't mistake, you can't eliminate "Using temporary" and "Using > filesort" because you are using an "order by". Try the explain again > removing order by and check the output. Thank you, I know, without order no problem: (root@localhost) [test]> explain select e.id from egyik e,masik m where e.id=m.id and e.duma='aaa'; +------+-------------+-------+------+---------------+-------+---------+-----------+------+--------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +------+-------------+-------+------+---------------+-------+---------+-----------+------+--------------------------+ | 1 | SIMPLE | e | ref | PRIMARY,e_idx | e_idx | 767 | const | 1 | Using where; Using index | | 1 | SIMPLE | m | ref | m_idx | m_idx | 4 | test.e.id | 1 | Using index | +------+-------------+-------+------+---------------+-------+---------+-----------+------+--------------------------+ 2 rows in set (0.02 sec) > When you use an order by, MySQL needs to use filesort and spends some time > sorting the result set. Also, create a temporary table with the rows > prevously. This is the reason. Not every situation. If the order column in the first table, no problem too: (root@localhost) [test]> explain select e.id from egyik e,masik m where e.id=m.id and e.duma='aaa'order by e.duma asc; +------+-------------+-------+------+---------------+-------+---------+-----------+------+--------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +------+-------------+-------+------+---------------+-------+---------+-----------+------+--------------------------+ | 1 | SIMPLE | e | ref | PRIMARY,e_idx | e_idx | 767 | const | 1 | Using where; Using index | | 1 | SIMPLE | m | ref | m_idx | m_idx | 4 | test.e.id | 1 | Using index | +------+-------------+-------+------+---------------+-------+---------+-----------+------+--------------------------+ 2 rows in set (0.00 sec) But i need to order with column in the second table. Bye! Lay -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql
