У меня следующий запрос, который выполняется очень медленно на mysql (83 секунды), но очень быстро на mariadb (.4 секунды).
Я проверил, что база данных имеет те же индексы и данные. Сервер Maria Db имеет меньшее количество процессоров (1VCPU), память (2 ГБ)
Mysql Серверы имеют 8 - 32 ГБ ОЗУ и четырехъядерные процессоры (пробовал 5.6,5.7 и 8.0 с аналогичными результатами).
В таблице phppos_inventory ~ 170000 строк, а в таблице phppos_items ~ 3000 строк
Вот запрос, таблицы и пояснения
SELECT /*+ SEMIJOIN(@subq MATERIALIZATION) */ SQL_CALC_FOUND_ROWS
1 AS _h,
`phppos_location_items`.`location_id` AS `location_id`,
`phppos_items`.`item_id`,
`phppos_items`.`name`,
`phppos_categories`.`id` AS `category_id`,
`phppos_categories`.`name` AS `category`,
`location`,
`company_name`,
`phppos_items`.`item_number`,
`size`,
`product_id`,
Coalesce(phppos_location_item_variations.cost_price,
phppos_item_variations.cost_price, phppos_location_items.cost_price,
phppos_items.cost_price, 0) AS cost_price,
Coalesce(phppos_location_item_variations.unit_price,
phppos_item_variations.unit_price, phppos_location_items.unit_price,
phppos_items.unit_price, 0) AS unit_price,
Sum(Coalesce(inv.trans_current_quantity, 0)) AS quantity,
Coalesce(phppos_location_item_variations.reorder_level,
phppos_item_variations.reorder_level, phppos_location_items.reorder_level,
phppos_items.reorder_level) AS reorder_level,
Coalesce(phppos_location_item_variations.replenish_level,
phppos_item_variations.replenish_level, phppos_location_items.replenish_level,
phppos_items.replenish_level) AS replenish_level,
description
FROM `phppos_inventory` `inv`
LEFT JOIN `phppos_items`
ON `phppos_items`.`item_id` = `inv`.`trans_items`
LEFT JOIN `phppos_location_items`
ON `phppos_location_items`.`item_id` = `phppos_items`.`item_id`
AND `phppos_location_items`.`location_id` = `inv`.`location_id`
LEFT JOIN `phppos_item_variations`
ON `phppos_items`.`item_id` = `phppos_item_variations`.`item_id`
AND `phppos_item_variations`.`id` = `inv`.`item_variation_id`
AND `phppos_item_variations`.`deleted` = 0
LEFT JOIN `phppos_location_item_variations`
ON `phppos_location_item_variations`.`item_variation_id` =
`phppos_item_variations`.`id`
AND `phppos_location_item_variations`.`location_id` =
`inv`.`location_id`
LEFT OUTER JOIN `phppos_suppliers`
ON `phppos_items`.`supplier_id` =
`phppos_suppliers`.`person_id`
LEFT OUTER JOIN `phppos_categories`
ON `phppos_items`.`category_id` = `phppos_categories`.`id`
WHERE inv.trans_id = (SELECT Max(inv1.trans_id)
FROM phppos_inventory inv1
WHERE inv1.trans_items = inv.trans_items
AND ( inv1.item_variation_id =
phppos_item_variations.id
OR phppos_item_variations.id IS NULL )
AND inv1.location_id = inv.location_id
AND inv1.trans_date < '2019-12-31 23:59:59')
AND inv.location_id IN( 1 )
AND `phppos_items`.`system_item` = 0
AND `phppos_items`.`deleted` = 0
AND `is_service` != 1
GROUP BY `phppos_items`.`item_id`
LIMIT 20
Объясните mysql (немного отличается от maria db, но я пытался использовать index, чтобы соответствовать плану выполнения, и все еще был медленным)
+------------------------------------------+-------+----------+------------------------------------+
| id | select_type | table | partitions | type | possible_keys | key | key_len | ref | rows | filtered | Extra |
+----+--------------------+---------------------------------+------------+--------+------------------------------+-------+----------+------------------------------------+
| 1 | PRIMARY | phppos_items | NULL | ref | PRIMARY,item_number,product_id,phppos_items_ibfk_1,deleted,phppos_items_ibfk_3,phppos_items_ibfk_4,phppos_items_ibfk_5,description,size,reorder_level,cost_price,unit_price,promo_price,last_modified,name,phppos_items_ibfk_6,deleted_system_item,custom_field_1_value,custom_field_2_value,custom_field_3_value,custom_field_4_value,custom_field_5_value,custom_field_6_value,custom_field_7_value,custom_field_8_value,custom_field_9_value,custom_field_10_value,verify_age,phppos_items_ibfk_7,item_inactive_index,tags,full_search,name_search,item_number_search,product_id_search,description_search,size_search,custom_field_1_value_search,custom_field_2_value_search,custom_field_3_value_search,custom_field_4_value_search,custom_field_5_value_search,custom_field_6_value_search,custom_field_7_value_search,custom_field_8_value_search,custom_field_9_value_search,custom_field_10_value_search | deleted | 4 | const | 21188 | 9.00 | Using index condition; Using where |
| 1 | PRIMARY | inv | NULL | ref | phppos_inventory_ibfk_1,location_id,phppos_inventory_custom | phppos_inventory_custom | 8 | pos.phppos_items.item_id,const | 3 | 100.00 | NULL |
| 1 | PRIMARY | phppos_location_items | NULL | eq_ref | PRIMARY,phppos_location_items_ibfk_2 | PRIMARY | 8 | const,pos.phppos_items.item_id | 1 | 100.00 | NULL |
| 1 | PRIMARY | phppos_item_variations | NULL | eq_ref | PRIMARY,phppos_item_variations_ibfk_1 | PRIMARY | 4 | pos.inv.item_variation_id | 1 | 100.00 | Using where |
| 1 | PRIMARY | phppos_location_item_variations | NULL | eq_ref | PRIMARY,phppos_item_attribute_location_values_ibfk_2 | PRIMARY | 8 | pos.phppos_item_variations.id,const | 1 | 100.00 | NULL |
| 1 | PRIMARY | phppos_suppliers | NULL | ref | person_id | person_id | 4 | pos.phppos_items.supplier_id | 1 | 100.00 | NULL |
| 1 | PRIMARY | phppos_categories | NULL | eq_ref | PRIMARY | PRIMARY | 4 | pos.phppos_items.category_id | 1 | 100.00 | NULL |
| 2 | DEPENDENT SUBQUERY | inv1 | NULL | ref | phppos_inventory_ibfk_1,location_id,trans_date,phppos_inventory_ibfk_4,phppos_inventory_custom | phppos_inventory_custom | 8 | pos.inv.trans_items,pos.inv.location_id | 3 | 50.00 | Using where; Using index |
+----+--------------------+---------------------------------+------------+--------+---------------------------------------------------------------------------------------------------------
Объяснить maria db:
+------+---------------------------------------------+-------+--------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+------+--------------------+---------------------------------+--------+------------------------------+
| 1 | PRIMARY | phppos_items | ref | PRIMARY,deleted,deleted_system_item | deleted | 4 | const | 23955 | Using where |
| 1 | PRIMARY | inv | ref | phppos_inventory_ibfk_1,location_id,phppos_inventory_custom | phppos_inventory_ibfk_1 | 4 | freelance_pos5.phppos_items.item_id | 2 | Using where |
| 1 | PRIMARY | phppos_location_items | eq_ref | PRIMARY,phppos_location_items_ibfk_2 | PRIMARY | 8 | const,freelance_pos5.phppos_items.item_id | 1 | |
| 1 | PRIMARY | phppos_item_variations | eq_ref | PRIMARY,phppos_item_variations_ibfk_1 | PRIMARY | 4 | freelance_pos5.inv.item_variation_id | 1 | Using where |
| 1 | PRIMARY | phppos_location_item_variations | eq_ref | PRIMARY,phppos_item_attribute_location_values_ibfk_2 | PRIMARY | 8 | freelance_pos5.phppos_item_variations.id,const | 1 | Using where |
| 1 | PRIMARY | phppos_suppliers | ref | person_id | person_id | 4 | freelance_pos5.phppos_items.supplier_id | 1 | Using where |
| 1 | PRIMARY | phppos_categories | eq_ref | PRIMARY | PRIMARY | 4 | freelance_pos5.phppos_items.category_id | 1 | Using where |
| 2 | DEPENDENT SUBQUERY | inv1 | ref | phppos_inventory_ibfk_1,location_id,trans_date,phppos_inventory_ibfk_4,phppos_inventory_custom | phppos_inventory_custom | 8 | freelance_pos5.inv.trans_items,freelance_pos5.inv.location_id | 2 | Using where; Using index |
+------+--------------------+---------------------------------+--------+------------------------------------------------------------------------------------------------+-------------------------+---------+---------------------------------------------------------------+-------+--------------------------+
Описанные таблицы (достигнуто ограничение числа символов StackOverflow)
https://pastebin.com/nhngSHb8
Создание таблиц:
https://pastebin.com/aWMeriqt
MYSQL (DEV BOX)
mysql> SHOW GLOBAL STATUS LIKE '%thread%';
+------------------------------------------+-------+
| Variable_name | Value |
+------------------------------------------+-------+
| Delayed_insert_threads | 0 |
| Performance_schema_thread_classes_lost | 0 |
| Performance_schema_thread_instances_lost | 0 |
| Slow_launch_threads | 0 |
| Threads_cached | 4 |
| Threads_connected | 1 |
| Threads_created | 5 |
| Threads_running | 1 |
+------------------------------------------+-------+
8 rows in set (0.06 sec)
MARIA DB
MariaDB [freelance_pos5]> SHOW GLOBAL STATUS LIKE '%thread%';
+------------------------------------------+-------+
| Variable_name | Value |
+------------------------------------------+-------+
| Delayed_insert_threads | 0 |
| Performance_schema_thread_classes_lost | 0 |
| Performance_schema_thread_instances_lost | 0 |
| Slow_launch_threads | 0 |
| Threadpool_idle_threads | 0 |
| Threadpool_threads | 0 |
| Threads_cached | 3 |
| Threads_connected | 2 |
| Threads_created | 5 |
| Threads_running | 1 |
| wsrep_applier_thread_count | 0 |
| wsrep_rollbacker_thread_count | 0 |
| wsrep_thread_count | 0 |
+------------------------------------------+-------+
13 rows in set (0.00 sec)