小编Bri*_*ter的帖子

我今天一直在对这个复杂的查询进行故障排除,认为这是一个性能问题.看来查询已陷入"统计"状态.它目前处于该状态1300秒.

我检查了所涉及的表的索引 - 我已经优化了表 - 可能导致这种挂起的原因是什么？

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 ', …

我正在使用以下查询,它返回预期的结果..除了连接结果似乎被切断的事实.

例:

"1965 Chevrolet Suburban, 
1958 Chevrolet Bel Air, 
1969 Chevrolet K20 Suburban, 
1967 Chevrolet Bel Air, 
1964 Chevrolet C10 Pickup, 
1970 Chevrolet G10 Van, 
1969 Chevrolet K20 Pickup, 
1965 Chevrolet Biscayne, 
1970 Chevrolet Brookwood, 
1964 Chevrolet P30 Series, 
1966 Chevrolet Bel Air, 
1967 Chevrolet C20 Pickup, 
1972 Chevrolet Blazer, 
1961 Chevrolet Biscayne, 
1962 Chevrolet Corvair, 
1968 Chevrolet Impala, 
1970 Chevrolet K30 Pickup, 
1967 Chevrolet C10 Pickup, 
1966 Chevrolet G10 Van, 
1968 Chevrolet K20 Pickup, 
1963 Chevrolet P30 Series, 
1966 …