如何优化此SQL查询？

Question

现在我有了这个，它可以检索大约16000条记录：

DECLARE @LINE_ID INT
SET @LINE_ID = 37
SELECT 
    a.eventType as 'evento', 
    a.tipo as 'tipo', 
    a.nroSoldadura as 'nro soldadura', 
    a.cuentaOdometrica as 'Distancia Absoluta [m]',
    a.x as 'x', 
    a.y as 'y', 
    a.z as 'z', 
    a.zonaGeografica as 'Zona geografica', 
    a.orientacionSoldadura as 'orientacion', 
    a.prof * 100 as 'prof maxima [%]',
    a.longitud as 'long. [mm]',
    a.ancho as 'ancho [mm]',
    a.IntExt as 'INT o EXT',
    a.cluster as 'Cluster',
    a.espesorPared as 'espesor de pared nominal',
    a.longitudEfectiva as 'longitud efectiva',
    a.anchoEfectivo as 'Ancho efectivo',
    a.areaEfectiva as 'Area efectiva',
    a.factorSeguridad as 'Factor de seguridad',
    a.MAOP as 'MAOP (kPa)',
    a.ruptura as 'Ruptura 0.85dL (kPa)',
    a.FER as 'FER',
    NULL as 'Diametro maximo',
    NULL as 'Diametro minimo',
    NULL as 'Ovalizacion',
    NULL as 'Ovalizacion axial',
    a.orientacionSoldadura as 'Orientacion soldadura',
    a.velocidadHerramienta as 'Velc Herr',
    a.comentarios as 'comentarios'
FROM ILI_IMPORT_MFL as a
JOIN ILI_INSPECTION as b ON a.ILI_INSPECTION_ID = b.ILI_INSPECTION_ID
WHERE 
    a.ID IN (
        SELECT TOP 1 c.ID
        FROM ILI_IMPORT_MFL as c 
        JOIN ILI_INSPECTION as d ON c.ILI_INSPECTION_ID = d.ILI_INSPECTION_ID
        WHERE a.nroSoldadura = c.nroSoldadura
            AND d.LINE_ID = @LINE_ID
        ORDER BY d.BEGIN_DATE 
    )
    AND b.LINE_ID = @LINE_ID
ORDER BY a.nroSoldadura, b.BEGIN_DATE 

因为ILI_INSPECTION包含我需要的日期和行ID，所以ILI_IMPORT_MFL和ILI_INSPECTION之间存在连接。
现在，由于有子查询，此查询大约需要6分钟才能执行。 子查询位于其中，因为每个nroSoldadura可能有多个行，而我只想要它们的最旧行。

我正在使用SQL Server 2008。
我该如何解决？ 谢谢。

编辑：尝试将索引添加到nroSoldadura和BEGIN_DATE列，并使查询时间减少到30秒。 看到一个可能的优化以便学习仍然很高兴。

Answer 1

您可以尝试使用ROW_NUMBER() ... PARTITION BY替换您的子查询：

DECLARE @LINE_ID INT
SET @LINE_ID = 37
SELECT 
    a.eventType as 'evento', 
    a.tipo as 'tipo', 
    a.nroSoldadura as 'nro soldadura', 
    a.cuentaOdometrica as 'Distancia Absoluta [m]',
    a.x as 'x', 
    a.y as 'y', 
    a.z as 'z', 
    a.zonaGeografica as 'Zona geografica', 
    a.orientacionSoldadura as 'orientacion', 
    a.prof * 100 as 'prof maxima [%]',
    a.longitud as 'long. [mm]',
    a.ancho as 'ancho [mm]',
    a.IntExt as 'INT o EXT',
    a.cluster as 'Cluster',
    a.espesorPared as 'espesor de pared nominal',
    a.longitudEfectiva as 'longitud efectiva',
    a.anchoEfectivo as 'Ancho efectivo',
    a.areaEfectiva as 'Area efectiva',
    a.factorSeguridad as 'Factor de seguridad',
    a.MAOP as 'MAOP (kPa)',
    a.ruptura as 'Ruptura 0.85dL (kPa)',
    a.FER as 'FER',
    NULL as 'Diametro maximo',
    NULL as 'Diametro minimo',
    NULL as 'Ovalizacion',
    NULL as 'Ovalizacion axial',
    a.orientacionSoldadura as 'Orientacion soldadura',
    a.velocidadHerramienta as 'Velc Herr',
    a.comentarios as 'comentarios'
    ROW_NUMBER() OVER (PARTITION BY a.ID ORDER BY d.BEGIN_DATE) As row
FROM ILI_IMPORT_MFL as a
JOIN ILI_INSPECTION as b ON a.ILI_INSPECTION_ID = b.ILI_INSPECTION_ID
WHERE 
    row = 1
    AND b.LINE_ID = @LINE_ID
ORDER BY a.nroSoldadura, b.BEGIN_DATE 

Answer 2

您要为此使用row_number() 。 您需要将其放在子查询中。 我认为这是您想要的：

select * from (
SELECT 
    a.eventType as 'evento', 
    a.tipo as 'tipo', 
    a.nroSoldadura as 'nro soldadura', 
    a.cuentaOdometrica as 'Distancia Absoluta [m]',
    a.x as 'x', 
    a.y as 'y', 
    a.z as 'z', 
    a.zonaGeografica as 'Zona geografica', 
    a.orientacionSoldadura as 'orientacion', 
    a.prof * 100 as 'prof maxima [%]',
    a.longitud as 'long. [mm]',
    a.ancho as 'ancho [mm]',
    a.IntExt as 'INT o EXT',
    a.cluster as 'Cluster',
    a.espesorPared as 'espesor de pared nominal',
    a.longitudEfectiva as 'longitud efectiva',
    a.anchoEfectivo as 'Ancho efectivo',
    a.areaEfectiva as 'Area efectiva',
    a.factorSeguridad as 'Factor de seguridad',
    a.MAOP as 'MAOP (kPa)',
    a.ruptura as 'Ruptura 0.85dL (kPa)',
    a.FER as 'FER',
    NULL as 'Diametro maximo',
    NULL as 'Diametro minimo',
    NULL as 'Ovalizacion',
    NULL as 'Ovalizacion axial',
    a.orientacionSoldadura as 'Orientacion soldadura',
    a.velocidadHerramienta as 'Velc Herr',
    a.comentarios as 'comentarios',
    ROW_NUMBER() over (partition by a.nroSoldadura order by begin_date desc) as seqnum
FROM ILI_IMPORT_MFL as a
JOIN ILI_INSPECTION as b ON a.ILI_INSPECTION_ID = b.ILI_INSPECTION_ID
where b.line_id = @line_id
)
where seqnum = 1