我正在对这里的一个相当复杂的 SQL 查询的性能进行故障排除。当我运行以下命令时,结果概述如下......
EXPLAIN SELECT
Import_Values.id,
Import_Values.part_id,
Import_Values.qty,
Import_Values.note,
Parts.partterminologyname,
GROUP_CONCAT(BaseVehicle.YearID, ' ', Make.MakeName, ' ', Model.modelname, ' ', SubModel.SubModelName SEPARATOR ', '),
GROUP_CONCAT(DISTINCT(EngineDesignation.EngineDesignationName) SEPARATOR ', '),
GROUP_CONCAT(DISTINCT(EngineVIN.EngineVINName) SEPARATOR ', '),
GROUP_CONCAT(DISTINCT(EngineBase.Liter) SEPARATOR ', '),
GROUP_CONCAT(DISTINCT(EngineBase.CC) SEPARATOR ', '),
GROUP_CONCAT(DISTINCT(EngineBase.CID) SEPARATOR ', '),
GROUP_CONCAT(DISTINCT(EngineBase.Cylinders) SEPARATOR ', '),
GROUP_CONCAT(DISTINCT(EngineBase.BlockType) SEPARATOR ', '),
GROUP_CONCAT(DISTINCT(EngineBase.EngBoreIn) SEPARATOR ', '),
GROUP_CONCAT(DISTINCT(EngineBase.EngBoreMetric) SEPARATOR ', '),
GROUP_CONCAT(DISTINCT(EngineBase.EngStrokeIn) SEPARATOR ', '),
GROUP_CONCAT(DISTINCT(EngineBase.EngStrokeMetric) SEPARATOR ', '),
GROUP_CONCAT(DISTINCT(FuelDeliveryType.FuelDeliveryTypeName) SEPARATOR ', '),
GROUP_CONCAT(DISTINCT(FuelDeliverySubType.FuelDeliverySubTypeName) SEPARATOR ', '),
GROUP_CONCAT(DISTINCT(FuelSystemControlType.FuelSystemControlTypeName) SEPARATOR ', '),
GROUP_CONCAT(DISTINCT(FuelSystemDesign.FuelSystemDesignName) SEPARATOR ', '),
GROUP_CONCAT(DISTINCT(Aspiration.AspirationName) SEPARATOR ', '),
GROUP_CONCAT(DISTINCT(CylinderHeadType.CylinderHeadTypeName) SEPARATOR ', '),
GROUP_CONCAT(DISTINCT(FuelType.FuelTypeName) SEPARATOR ', '),
GROUP_CONCAT(DISTINCT(IgnitionSystemType.IgnitionSystemTypeName) SEPARATOR ', '),
GROUP_CONCAT(DISTINCT(Mfr.MfrName) SEPARATOR ', ')
FROM
Import_Values
INNER JOIN BaseVehicle
ON Import_Values.base_vehicle_id=BaseVehicle.BaseVehicleID
INNER JOIN Parts
ON Import_Values.part_type_id=Parts.PartTerminologyID
INNER JOIN Make
ON BaseVehicle.MakeID=Make.MakeID
INNER JOIN Model
ON BaseVehicle.ModelID=Model.ModelID
INNER JOIN Vehicle
ON Import_Values.base_vehicle_id=Vehicle.BaseVehicleID
INNER JOIN SubModel
ON Vehicle.SubModelID=SubModel.SubModelID
INNER JOIN VehicleToEngineConfig
ON Vehicle.VehicleID=VehicleToEngineConfig.VehicleID
INNER JOIN EngineConfig
ON VehicleToEngineConfig.EngineConfigID=EngineConfig.EngineConfigID
INNER JOIN EngineDesignation
ON EngineConfig.EngineDesignationID=EngineDesignation.EngineDesignationID
INNER JOIN EngineVIN
ON EngineConfig.EngineVINID=EngineVIN.EngineVINID
INNER JOIN EngineBase
ON EngineConfig.EngineBaseID=EngineBase.EngineBaseID
INNER JOIN FuelDeliveryConfig
ON EngineConfig.FuelDeliveryConfigID=FuelDeliveryConfig.FuelDeliveryConfigID
INNER JOIN FuelDeliveryType
ON FuelDeliveryConfig.FuelDeliveryTypeID=FuelDeliveryType.FuelDeliveryTypeID
INNER JOIN FuelDeliverySubType
ON FuelDeliveryConfig.FuelDeliverySubTypeID=FuelDeliverySubType.FuelDeliverySubTypeID
INNER JOIN FuelSystemControlType
ON FuelDeliveryConfig.FuelSystemControlTypeID=FuelSystemControlType.FuelSystemControlTypeID
INNER JOIN FuelSystemDesign
ON FuelDeliveryConfig.FuelSystemDesignID=FuelSystemDesign.FuelSystemDesignID
INNER JOIN Aspiration
ON EngineConfig.AspirationID=Aspiration.AspirationID
INNER JOIN CylinderHeadType
ON EngineConfig.CylinderHeadTypeID=CylinderHeadType.CylinderHeadTypeID
INNER JOIN FuelType
ON EngineConfig.FuelTypeID=FuelType.FuelTypeID
INNER JOIN IgnitionSystemType
ON EngineConfig.IgnitionSystemTypeID=IgnitionSystemType.IgnitionSystemTypeID
INNER JOIN Mfr
ON EngineConfig.EngineMfrID=Mfr.MfrID
GROUP BY part_id
结果表明 Import_Values 表有 147377 行,类型为“ALL”,FuelDeliveryType 有 3 行,类型为“ALL”。根据我的阅读,“ALL”类型会导致性能不佳。
我添加了一个索引,但它仍然显示“全部”——还有什么我必须做的吗?
谢谢!