mysql> explain select * from cuenta where rutaCuenta like 'CTV%'; +----+-------------+--------+-------+---------------+------------+---------+------+--------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+--------+-------+---------------+------------+---------+------+--------+-------------+ | 1 | SIMPLE | cuenta | range | rutaCuenta | rutaCuenta | 258 | NULL | 876824 | Using where | +----+-------------+--------+-------+---------------+------------+---------+------+--------+-------------+ 1 row in set (0.00 sec)
mysql> explain select * from cuenta where rutaCuenta like 'CTV%'; +----+-------------+--------+------+---------------+------+---------+------+---------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+--------+------+---------------+------+---------+------+---------+-------------+ | 1 | SIMPLE | cuenta | ALL | rutaCuenta | NULL | NULL | NULL | 5274306 | Using where | +----+-------------+--------+------+---------------+------+---------+------+---------+-------------+ 1 row in set (0.00 sec) Any ideas? I'm creating running a process which populates the rutaCuenta field with some codification to retrieve some hierarchical based in that field... I did the explain meanwhile doing the populating process, and it showed the usage of the index, then, some time later, it show, for the same query, the usage of no index... Why? I really appreciate some guidance... I find no logic at all...
