mysql查询需要很长时间

Question

我的以下查询需要 10 秒以上。我如何优化这个查询。请建议添加索引的字段。 此查询是用于距离搜索的 drupal 视图。

    SELECT DISTINCT location.lid AS location_lid, node.nid AS nid, location.name AS location_name, location_phone.phone AS location_phone_phone, location_fax.fax AS location_fax_fax, node.title AS node_title, node.language AS node_language, location.additional AS location_additional, location.city AS location_city, location.latitude AS location_latitude, location.longitude AS location_longitude, location.country AS location_country, location.postal_code AS location_postal_code, location.province AS location_province, location.street AS location_street, field_data_field_showroom_level.field_showroom_level_value AS field_data_field_showroom_level_field_showroom_level_value, field_data_field_showroom_type.field_showroom_type_value AS field_data_field_showroom_type_field_showroom_type_value, field_data_field_showroom_inventory_records.field_showroom_inventory_records_value AS field_data_field_showroom_inventory_records_field_showroom_i, field_data_field_record_type_id.field_record_type_id_value AS field_data_field_record_type_id_field_record_type_id_value, field_data_field_toto_gallery.field_toto_gallery_value AS field_data_field_toto_gallery_field_toto_gallery_value, 'node' AS field_data_field_showroom_location_node_entity_type, 'node' AS field_data_field_day_of_operation_node_entity_type, 'node' AS field_data_field_day_of_operation_comments_node_entity_type, 'node' AS field_data_field_showroom_open_node_entity_type, 'node' AS field_data_field_showroom_close_node_entity_type, 'node' AS field_data_field_appointment_needed_node_entity_type, (COALESCE(ACOS(0.83308162381476*COS(RADIANS(location.latitude))*(0.098658826854837*COS(RADIANS(location.longitude)) + -0.99512131716873*SIN(RADIANS(location.longitude))) + 0.55315007734083*SIN(RADIANS(location.latitude))), 0.00000)*6371570.9190939) AS location_distance, 'node' AS field_data_field_salesforce_id_node_entity_type, 'node' AS field_data_field_multiple_product_sku_node_entity_type, 'node' AS field_data_field_product_types_node_entity_type, 'node' AS field_data_field_toto_gallery_node_entity_type, 'node' AS field_data_field_showroom_level_node_entity_type
FROM 
node node
LEFT JOIN location_instance location_instance ON node.vid = location_instance.vid
LEFT JOIN location location ON location_instance.lid = location.lid
INNER JOIN field_data_field_toto_gallery field_data_field_toto_gallery ON node.nid = field_data_field_toto_gallery.entity_id AND (field_data_field_toto_gallery.entity_type = 'node' AND field_data_field_toto_gallery.deleted = '0')
LEFT JOIN field_data_field_multiple_product_sku field_data_field_multiple_product_sku ON node.nid = field_data_field_multiple_product_sku.entity_id AND (field_data_field_multiple_product_sku.entity_type = 'node' AND field_data_field_multiple_product_sku.deleted = '0')
LEFT JOIN location_phone location_phone ON location_instance.lid = location_phone.lid
LEFT JOIN location_fax location_fax ON location_instance.lid = location_fax.lid
LEFT JOIN field_data_field_showroom_level field_data_field_showroom_level ON node.nid = field_data_field_showroom_level.entity_id AND (field_data_field_showroom_level.entity_type = 'node' AND field_data_field_showroom_level.deleted = '0')
LEFT JOIN field_data_field_showroom_type field_data_field_showroom_type ON node.nid = field_data_field_showroom_type.entity_id AND (field_data_field_showroom_type.entity_type = 'node' AND field_data_field_showroom_type.deleted = '0')
LEFT JOIN field_data_field_showroom_inventory_records field_data_field_showroom_inventory_records ON node.nid = field_data_field_showroom_inventory_records.entity_id AND (field_data_field_showroom_inventory_records.entity_type = 'node' AND field_data_field_showroom_inventory_records.deleted = '0')
LEFT JOIN field_data_field_record_type_id field_data_field_record_type_id ON node.nid = field_data_field_record_type_id.entity_id AND (field_data_field_record_type_id.entity_type = 'node' AND field_data_field_record_type_id.deleted = '0')
WHERE ((    (node.status = '1') 
        AND (node.type IN  ('showrooms')) 
           AND (location.latitude > '32.859795378699'
           AND location.latitude < '34.306986221301'
           AND location.longitude > '-85.206632058424'
           AND location.longitude < '-83.469478341576')
        AND ((COALESCE(ACOS(0.83308162574562*COS(RADIANS(location.latitude))*(0.098658823381208*COS(RADIANS(location.longitude)) + -0.99512131751311*SIN(RADIANS(location.longitude))) + 0.55315007443282*SIN(RADIANS(location.latitude))), 0.00000)*6371570.9191628) < '80467.35')
        AND (location.province = 'GA') 
        AND (location.city LIKE 'Atlanta' ESCAPE '\\') )
        AND( (field_data_field_toto_gallery.field_toto_gallery_value = '1')
           OR (field_data_field_multiple_product_sku.field_multiple_product_sku_value NOT LIKE 'NULL' ESCAPE '\\') ))

ORDER BY field_data_field_showroom_level_field_showroom_level_value DESC, 
         field_data_field_showroom_type_field_showroom_type_value DESC, 
         location_distance ASC, 
         field_data_field_showroom_inventory_records_field_showroom_i DESC,
         field_data_field_record_type_id_field_record_type_id_value ASC,          
         field_data_field_toto_gallery_field_toto_gallery_value DESC
LIMIT 10 OFFSET 0

Answer 1

我建议你了解一下 MySQL 的 PROCEDURE ANALYSE 函数：http://dev.mysql.com/doc/refman/5.0/en/procedure-analyse.html

它会告诉您哪些连接可能没有可以使用的索引。仅查看您的查询但不了解表的结构或数据，我们无法为您提供良好的建议。通常，您应该在每一列上都有一个索引，在查询的 JOIN 和 ORDER BY 部分中使用，并且您可能对 WHERE 子句中使用的列有一些索引。

Answer 2

这里有一些事情可以立即尝试，看看是否可以提高性能。

1. 在(province, city, latitude, longitude, lid) 的location 表上尝试复合索引。该复合索引有望加速您的位置的WHERE 标准计算。
2. 确保您的 latitude 和 longitude 列具有 FLOAT 或 DOUBLE 数据类型。
3. 在(status, type, vid) 的node 表上尝试复合索引。该索引应该有助于在您的 WHERE 子句中找到确切的 node 记录并加速您的联接。
4. 从WHERE 子句中消除球面几何计算。您已经有边界框范围限制，并且您已经按距离排序，因此您不应该以这种方式获得太多额外的位置。而且，如果这样做，它们的距离不应超过 4/pi。
5. 你能摆脱SELECT DISTINCT而只使用SELECT吗？查找不同的值是一项数据密集型操作。

有关距离计算和边界框优化的一些有用信息，请参阅此处。 http://www.plumislandmedia.net/mysql/haversine-mysql-nearest-loc/