1.问题分析
慢sql,查询155.906秒; 缺少索引
2.解决方案
索引优化建议:
- 建议在数据表 irobotbox_marketpublish.M_Mercadolibre_Notiftransfer_Site 的 UserId,Status,SiteId 列上添加如下索引,以提高查询性能:
ALTER TABLE `irobotbox_marketpublish`.`M_Mercadolibre_Notiftransfer_Site` ADD INDEX `idx_UserId_Status_SiteId` (`UserId`, `Status`, `SiteId`)
注意:在业务高峰期,变更表结构存在风险,请谨慎操作!
3.慢sql
SELECT `Id` AS `Id`, `UserId` AS `UserId`, `ApplicationId` AS `ApplicationId`, 2 AS `Type`, `SiteId` AS `Resource` , `Status` AS `Status`, `SentTime` AS `Sent`, `SentTime` AS `Received` FROM `M_Mercadolibre_Notiftransfer_Site` WHERE `UserId` = '1165164882' AND `Status` = 0 AND NOT (`SiteId` IS NULL OR `SiteId` = '') GROUP BY `SiteId`, `UserId` ORDER BY Id DESC LIMIT 400, 200
