我最近将MySQL数据库从5.0.67迁移到5.5.44-MariaDB，我有一个查询，在5.0.67中执行不到一秒，但在5.5.44中需要超过100秒。
在我开始重写查询之前，我想找到两台服务器之间的区别，我的猜测是它可能是一个在MariaDB中不理想但我找不到它的设置。
5.0.67的配置：
set-variable = innodb_buffer_pool_size=2M
set-variable = innodb_additional_mem_pool_size=500K
set-variable = innodb_log_buffer_size=500K
set-variable = innodb_thread_concurrency=2
[mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
timezone=America/Chicago
set-variable = innodb_buffer_pool_size=2M
set-variable = innodb_additional_mem_pool_size=500K
set-variable = innodb_log_buffer_size=500K
set-variable = innodb_thread_concurrency=2
#increse lock wait timout
innodb_lock_wait_timeout = 120
5.5.44的配置：
key_buffer_size = 16M
max_allowed_packet = 1M
sort_buffer_size = 512K
net_buffer_length = 8K
read_buffer_size = 256K
read_rnd_buffer_size = 512K
myisam_sort_buffer_size = 8M
innodb_buffer_pool_size = 16M
innodb_additional_mem_pool_size = 2M
innodb_log_buffer_size = 8M
[mysqldump]
quick
max_allowed_packet = 16M
[mysql]
no-auto-rehash
[myisamchk]
key_buffer_size = 20M
sort_buffer_size = 20M
read_buffer = 2M
write_buffer = 2M
[mysqlhotcopy]
interactive-timeout
查询：
SELECT
node.user_id,
node.user_id as id,
node.name,
node.status,
node.left_id,
node.right_id,
node.locked,
CONCAT( node.name, ' ', node.surname) as fullname,
(COUNT(parent.name) - (sub_tree.level + 1)) AS level
FROM
users AS node ,
users AS parent ,
users AS sub_parent ,
(
SELECT
node.name,
node.user_id,
(COUNT(parent.name) - 1) AS level
FROM
users AS node,
users AS parent
WHERE
node.left_id BETWEEN parent.left_id AND parent.right_id
AND
node.user_id = '29151'
GROUP BY node.name
ORDER BY node.left_id
) AS sub_tree
WHERE
node.left_id BETWEEN parent.left_id AND parent.right_id
AND
node.left_id BETWEEN sub_parent.left_id AND sub_parent.right_id
AND
sub_parent.user_id = sub_tree.user_id
GROUP BY
node.user_id
HAVING
1 = 1
and node.locked = 0
and level in ( 1,2,3,4)
ORDER BY node.left_id ;