title: SQL Query Stuck in Statistics State
body: <p>I've been troubleshooting this complex query today, thinking it was a performance issue. It appears that the query is getting stuck into the 'Statistics' state. It is currently in that state for 1300 seconds.</p>
  
  <p>I've checked the indexes for the tables involved -- I've optimized the table -- what could be causing this hang?</p>
  
  <pre><code>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 ', '),
      GROUP_CONCAT(DISTINCT(EngineVersion.EngineVersion) SEPARATOR ', '),
      GROUP_CONCAT(DISTINCT(Valves.ValvesPerEngine) SEPARATOR ', '),
      GROUP_CONCAT(DISTINCT(BedLength.BedLength) SEPARATOR ', '),
      GROUP_CONCAT(DISTINCT(BedLength.BedLengthMetric) 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
      INNER JOIN EngineVersion
          ON EngineConfig.EngineVersionID=EngineVersion.EngineVersionID
      INNER JOIN Valves
          ON EngineConfig.ValvesID=Valves.Valvesid
      INNER JOIN VehicleToBedConfig
          ON Vehicle.VehicleID=VehicleToBedConfig.VehicleID
      INNER JOIN BedConfig
          ON VehicleToBedConfig.BedConfigID=BedConfig.BedConfigID
      INNER JOIN BedLength
          ON BedConfig.BedLengthID=BedLength.BedLengthID
      GROUP BY part_id
  </code></pre>