我正在尝试解决我们需要为内部目的运行的查询.此查询不是应用程序的一部分,因此它不必非常有效,但我希望它尽可能快,以便我们可以获得我们需要前进的数据集.
我发现的第一个问题是查询陷入统计状态.通过在mySQL配置中添加以下内容来解决这个问题…
optimizer_search_depth = 0
现在查询直接进入’将数据复制到tmp表’,到目前为止已经发生了超过5分钟.我们的服务器非常强大,我们有128GB的RAM,所以我不相信它是一个资源问题.我确实认为查询本身可能需要进行一些优化,这就是我想要的指导,如果可能的话.
“EXPLAIN SELECT”can be seen here的结果.在运行EXPLAIN SELECT之前,我对此数据库中的所有表执行了“ANALYZE”(为此一次性查询而创建).
查询本身在这里：
SELECT DISTINCT
IAN.sku,
IAN.notes,
Parts.partterminologyname,
BaseVehicle.YearID,
Make.MakeName,
Model.modelname,
SubModel.SubModelName,
CONCAT(EngineBase.Cylinders, ' Cyl ', EngineBase.Liter, 'L') as engine,
Positions.position,
BedLength.BedLength,
BedLength.BedLengthMetric,
BedType.BedTypeName,
BodyNumDoors.BodyNumDoors,
BodyType.BodyTypeName,
FrontBrakeType.BrakeTypeName,
RearBrakeType.BrakeTypeName,
BrakeSystem.BrakeSystemName,
BrakeABS.BrakeABSName,
DriveType.DriveTypeName,
EngineDesignation.EngineDesignationName,
EngineVIN.EngineVINName,
Valves.ValvesPerEngine,
EngineBase.Liter,
EngineBase.CC,
EngineBase.CID,
EngineBase.Cylinders,
EngineBase.BlockType,
EngineBase.EngBoreIn,
EngineBase.EngBoreMetric,
EngineBase.EngStrokeIn,
EngineBase.EngStrokeMetric,
FuelDeliveryType.FuelDeliveryTypeName,
FuelDeliverySubType.FuelDeliverySubTypeName,
FuelSystemControlType.FuelSystemControlTypeName,
FuelSystemDesign.FuelSystemDesignName,
Aspiration.AspirationName,
CylinderHeadType.CylinderHeadTypeName,
FuelType.FuelTypeName,
IgnitionSystemType.IgnitionSystemTypeName,
EngineMfr.MfrName,
EngineVersion.EngineVersion,
PowerOutput.HorsePower,
PowerOutput.KilowattPower,
MfrBodyCode.MfrBodyCodeName,
SpringType.SpringTypeName,
SteeringType.SteeringTypeName,
SteeringSystem.SteeringSystemName,
TransmissionType.TransmissionTypeName,
TransmissionNumSpeeds.TransmissionNumSpeeds,
TransmissionMfrCode.TransmissionMfrCode,
TransElecControlled.ElecControlled,
TransmissionMfr.MfrName,
WheelBase.WheelBase,
WheelBase.WheelBaseMetric
FROM
Import_AcesApplication_New IAN
INNER JOIN BaseVehicle
ON IAN.base_vehicle_id = BaseVehicle.BaseVehicleID
INNER JOIN Make
ON BaseVehicle.MakeID = Make.MakeID
INNER JOIN Model
ON BaseVehicle.ModelID = Model.ModelID
INNER JOIN Positions
ON IAN.position_id = Positions.PositionID
INNER JOIN Parts
ON IAN.part_type_id = Parts.PartTerminologyID
INNER JOIN Vehicle
ON IAN.base_vehicle_id = Vehicle.BaseVehicleID
INNER JOIN SubModel
ON Vehicle.SubModelID = SubModel.SubModelID
INNER JOIN VehicleConfig
ON Vehicle.VehicleID = VehicleConfig.VehicleID
INNER JOIN EngineConfig
ON VehicleConfig.EngineConfigID = EngineConfig.EngineConfigID
INNER JOIN EngineBase
ON EngineConfig.EngineBaseID = EngineBase.EngineBaseID
INNER JOIN EngineDesignation
ON EngineConfig.EngineDesignationID = EngineDesignation.EngineDesignationID
INNER JOIN EngineVIN
ON EngineConfig.EngineVINID = EngineVIN.EngineVINID
INNER JOIN Valves
ON EngineConfig.ValvesID = Valves.Valvesid
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 EngineMfr
ON EngineConfig.EngineMfrID = EngineMfr.MfrID
INNER JOIN EngineVersion
ON EngineConfig.EngineVersionID = EngineVersion.EngineVersionID
INNER JOIN PowerOutput
ON EngineConfig.PowerOutputId = PowerOutput.PowerOutputId
INNER JOIN BedConfig
ON VehicleConfig.BedConfigID = BedConfig.BedConfigID
INNER JOIN BedLength
ON BedConfig.BedLengthID = BedLength.BedLengthID
INNER JOIN BedType
ON BedConfig.BedTypeID = BedType.BedTypeID
INNER JOIN BodyStyleConfig
ON VehicleConfig.BodyStyleConfigID = BodyStyleConfig.BodyStyleConfigID
INNER JOIN BodyNumDoors
ON BodyStyleConfig.BodyNumDoorsID = BodyNumDoors.BodyNumDoorsID
INNER JOIN BodyType
ON BodyStyleConfig.BodyTypeID = BodyType.BodyTypeID
INNER JOIN BrakeConfig
ON VehicleConfig.BrakeConfigID = BrakeConfig.BrakeConfigID
INNER JOIN BrakeType FrontBrakeType
ON BrakeConfig.FrontBrakeTypeID = FrontBrakeType.BrakeTypeID
INNER JOIN BrakeType RearBrakeType
ON BrakeConfig.RearBrakeTypeID = RearBrakeType.BrakeTypeID
INNER JOIN BrakeSystem
ON BrakeConfig.BrakeSystemID = BrakeSystem.BrakeSystemID
INNER JOIN BrakeABS
ON BrakeConfig.BrakeABSID = BrakeABS.BrakeABSID
INNER JOIN DriveType
ON VehicleConfig.DriveTypeID = DriveType.DriveTypeID
INNER JOIN MfrBodyCode
ON VehicleConfig.MfrBodyCodeID = MfrBodyCode.MfrBodyCodeID
INNER JOIN SpringType
ON VehicleConfig.SpringTypeConfigID = SpringType.SpringTypeID
INNER JOIN SteeringConfig
ON VehicleConfig.SteeringConfigID = SteeringConfig.SteeringConfigID
INNER JOIN SteeringType
ON SteeringConfig.SteeringConfigID = SteeringType.SteeringTypeID
INNER JOIN SteeringSystem
ON SteeringConfig.SteeringSystemID = SteeringSystem.SteeringSystemID
INNER JOIN Transmission
ON VehicleConfig.TransmissionID = Transmission.TransmissionID
INNER JOIN TransmissionBase
ON Transmission.TransmissionBaseID = TransmissionBase.TransmissionBaseID
INNER JOIN TransmissionType
ON TransmissionBase.TransmissionTypeID = TransmissionType.TransmissionTypeID
INNER JOIN TransmissionNumSpeeds
ON TransmissionBase.TransmissionNumSpeedsID = TransmissionNumSpeeds.TransmissionNumSpeedsID
INNER JOIN TransmissionControlType
ON TransmissionBase.TransmissionControlTypeID = TransmissionControlType.TransmissionControlTypeID
INNER JOIN TransmissionMfrCode
ON Transmission.TransmissionMfrCodeID = TransmissionMfrCode.TransmissionMfrCodeID
INNER JOIN ElecControlled TransElecControlled
ON Transmission.TransmissionElecControlledID = TransElecControlled.ElecControlledID
INNER JOIN Mfr TransmissionMfr
ON Transmission.TransmissionMfrID = TransmissionMfr.MfrID
INNER JOIN WheelBase
ON VehicleConfig.WheelbaseID = WheelBase.WheelBaseID
LIMIT
0,10
由于数据库的设置方式,查询中有许多主要的JOINS.数据库是我们行业的标准,并不是我想要改变的.应该注意的是,这个查询可能每隔几个月才运行一次,所以在优化它时很重要,它不一定非常有效.对最终结果的唯一期望是我们没有等待数据准备就绪的日期和天数.
我很感激任何有关这方面的指导,如果对此有任何建议,我会道歉.
最佳答案 您的查询似乎完美无缺.您的主表是“Import_AcesApplication_New”表,其余所有表都是从主表派生的查找表.我有一个类似的问题,政府拨款/合同查询查询20个表和查询窒息,这是针对1500万条记录
只需添加关键字即可
“STRAIGHT_JOIN”
选择STRAIGHT_JOIN [查询的其余部分]
它强制引擎以“按照您提供的顺序”运行查询.它可能试图过分分析哪个表具有最低记录,最佳索引等,并通过一些奇怪的表选择向后工作.
此外,编辑原始查询以更好地显示通过层次结构的相关链接以提高可读性
我希望您的所有查找表都在其主键上有索引,但您也可以通过覆盖索引获益,因此每次查找的原始数据页不一定是必需的.
Table Index suggestion
Import_AcesApplication_New ( sku, notes, base_vehicle_id, position_id, part_type_id )
BaseVehicle ( BaseVehicleID, MakeID, ModelID, YearID )
Make ( MakeID, MakeName )
Model ( ModelID, modelname )
Positions ( PositionID, Position )
Parts ( PartTerminologyID, partterminologyname )
Vehicle ( BaseVehicleID, SubModelID, VehicleID )
SubModel ( SubModelID, SubModelName )
VehicleConfig ( VehicleID ) -- too many other fields to be practical
EngineConfig ( EngineConfigID ) -- too many to be practical
EngineBase ( EngineBaseID ) -- too many to be practical
EngineDesignation ( EngineDesignationID, EngineDesignationName )
EngineVIN ( EngineVINID, EngineVINName )
Valves ( Valvesid, ValvesPerEngine )
FuelDeliveryConfig ( FuelDeliveryConfigID, FuelDeliveryTypeID, FuelDeliverySubTypeID, FuelSystemControlTypeID, FuelSystemDesignID )
FuelDeliveryType ( FuelDeliveryTypeID, FuelDeliveryTypeName )
FuelDeliverySubType ( FuelDeliverySubTypeID, FuelDeliverySubTypeName )
FuelSystemControlType ( FuelSystemControlTypeID, FuelSystemControlTypeName )
FuelSystemDesign ( FuelSystemDesignID, FuelSystemDesignName )
Aspiration ( AspirationID, AspirationName )
CylinderHeadType ( CylinderHeadTypeID, CylinderHeadTypeName )
FuelType ( FuelTypeID, FuelTypeName )
IgnitionSystemType ( IgnitionSystemTypeID, IgnitionSystemTypeName )
EngineMfr ( MfrID, MfrName )
EngineVersion ( EngineVersionID, EngineVersion )
PowerOutput ( PowerOutputId, HorsePower, KilowattPower )
BedConfig ( BedConfigID, BedLengthID, BedTypeID )
BedLength ( BedLengthID, BedLength, BedLengthMetric
BedType ( BedTypeID, BedTypeName )
BodyStyleConfig ( BodyStyleConfigID, BodyNumDoorsID, BodyTypeID )
BodyNumDoors ( BodyNumDoorsID, BodyNumDoors )
BodyType ( BodyTypeID, BodyTypeName )
BrakeConfig ( BrakeConfigID, FrontBrakeTypeID, RearBrakeTypeID, BrakeSystemID, BrakeABSID )
BrakeType ( BrakeTypeID, BrakeTypeName )
BrakeSystem ( BrakeSystemID, BrakeSystemName )
BrakeABS ( BrakeABSID, BrakeABSName )
DriveType ( DriveTypeID, DriveTypeName )
MfrBodyCode ( MfrBodyCodeID, MfrBodyCodeName )
SpringType ( SpringTypeID, SpringTypeName )
SteeringConfig ( SteeringConfigID, SteeringTypeID, SteeringSystemID) -- see note below indexes via JOIN
SteeringType ( SteeringTypeID, SteeringTypeName )
SteeringSystem ( SteeringSystemID, SteeringSystemName )
Transmission ( TransmissionID, TransmissionBaseID )
TransmissionBase ( TransmissionBaseID, TransmissionTypeID, TransmissionNumSpeedsID, TransmissionControlTypeID )
TransmissionType ( TransmissionTypeID, TransmissionTypeName )
TransmissionNumSpeeds ( TransmissionNumSpeedsID, TransmissionNumSpeeds )
TransmissionControlType ( TransmissionControlTypeID, ??? ) -- possible description column per note below
TransmissionMfrCode ( TransmissionMfrCodeID, TransmissionMfrCode )
ElecControlled ( ElecControlledID, ElecControlled )
Mfr ( MfrID, MfrName )
WheelBase ( WheelBaseID, WheelBase, WheelBaseMetric )
另外,在查看JOIN以获取覆盖索引时,我注意到转向配置的转向是基于转向类型的
ON SteeringConfig.SteeringConfigID = SteeringType.SteeringTypeID
这应该是……
ON SteeringConfig.SteeringTypeID = SteeringType.SteeringTypeID
在另一个项目… TransmissionControlType加入,但你没有从输出查询中拉出任何列…可能是有这么多表/连接的轻微疏忽.
这些应该有助于查询中的覆盖索引
