一、环境 1、基本情况 测试机3台,4核,8G 数据库:mysql 5.7.40 数据库升级:mysql8.0.32 2、数据导入方式 mysqldump导出,mysql导入。 3、测试数据 4、查询语句 SELECT `T1`.`Id` AS `Id`, `T1`.`Code` AS `Code`, `T1`.`Type` AS `Type`, `T1`.`System` AS `System`, `T1`.`Name` AS `Name`, `T1`.`Attachment` AS `Attachment`, …