SQL Server - 存储过程突然变慢

Question

我昨天编写了一个存储过程，通常在一秒钟内完成。今天，大约需要 18 秒。我昨天也遇到了这个问题，似乎可以通过删除并重新创建存储过程来解决。如今，这个伎俩似乎不起作用了。:(

有趣的是，如果我复制存储过程的主体并将其作为简单查询执行，它会很快完成。事实似乎是它是一个存储过程，导致速度变慢......！

有谁知道可能是什么问题？我一直在寻找答案，但他们通常建议通过查询分析器运行它，但我没有 - 我现在使用 SQL Server 2008 Express。

存储过程如下；

ALTER PROCEDURE [dbo].[spGetPOIs]
    @lat1 float,
    @lon1 float,
    @lat2 float,
    @lon2 float,
    @minLOD tinyint, 
    @maxLOD tinyint,
    @exact bit
AS
BEGIN
    -- Create the query rectangle as a polygon
    DECLARE @bounds geography;
    SET @bounds = dbo.fnGetRectangleGeographyFromLatLons(@lat1, @lon1, @lat2, @lon2);

    -- Perform the selection
    if (@exact = 0)
    BEGIN
        SELECT [ID], [Name], [Type], [Data], [MinLOD], [MaxLOD], [Location].[Lat] AS [Latitude], [Location].[Long] AS [Longitude], [SourceID]
        FROM [POIs]
        WHERE
            NOT ((@maxLOD  [MaxLOD])) AND
            (@bounds.Filter([Location]) = 1)
    END
    ELSE
    BEGIN
        SELECT [ID], [Name], [Type], [Data], [MinLOD], [MaxLOD], [Location].[Lat] AS [Latitude], [Location].[Long] AS [Longitude], [SourceID]
        FROM [POIs]
        WHERE
            NOT ((@maxLOD  [MaxLOD])) AND
            (@bounds.STIntersects([Location]) = 1)
    END

END

“POI”表具有 MinLOD、MaxLOD 索引和 Location 空间索引。

Answer 1

啊，它可以查询的计划很烂？

SP把汇编/查询lpan deterined上首先使用根据不同参数。因此，参数的第一个电话(在没有lpan是本)确定查询的计划。在一个必备条件，我得下降，从高速缓存，新的计划产生的。

下一次运行速度慢，可能使一个电话使用的查询分析，并得到所选择的计划，并检查它看起来如何。

如果是这样的-放在一个opton重新编译SP在每一个电话(与重新编译).

Answer 2

参数嗅探 去谷歌上查询. 。试试这个，这会将输入参数“重新映射”到局部变量，以防止 SQL Server 尝试根据参数猜测查询计划：

ALTER PROCEDURE [dbo].[spGetPOIs]
    @lat1 float,
    @lon1 float,
    @lat2 float,
    @lon2 float,
    @minLOD tinyint, 
    @maxLOD tinyint,
    @exact bit
AS
BEGIN
DECLARE @X_lat1 float,
    @X_lon1 float,
    @X_lat2 float,
    @X_lon2 float,
    @X_minLOD tinyint, 
    @X_maxLOD tinyint,
    @X_exact bit



    -- Create the query rectangle as a polygon
    DECLARE @bounds geography;
    SET @bounds = dbo.fnGetRectangleGeographyFromLatLons(@X_lat1, @X_lon1, @lX_at2, @X_lon2);

    -- Perform the selection
    if (@exact = 0)
    BEGIN
        SELECT [ID], [Name], [Type], [Data], [MinLOD], [MaxLOD], [Location].[Lat] AS [Latitude], [Location].[Long] AS [Longitude], [SourceID]
        FROM [POIs]
        WHERE
            NOT ((@X_maxLOD  [MaxLOD])) AND
            (@bounds.Filter([Location]) = 1)
    END
    ELSE
    BEGIN
        SELECT [ID], [Name], [Type], [Data], [MinLOD], [MaxLOD], [Location].[Lat] AS [Latitude], [Location].[Long] AS [Longitude], [SourceID]
        FROM [POIs]
        WHERE
            NOT ((@X_maxLOD  [MaxLOD])) AND
            (@bounds.STIntersects([Location]) = 1)
    END

END

Answer 3

我也有类似的问题，这是与指数相关的。结果 重建他们帮助SP快速再次运行。

我发现溶液这里

USE master;
GO

CREATE PROC DatabaseReIndex(@Database VARCHAR(100)) AS 
BEGIN
  DECLARE @DbID SMALLINT=DB_ID(@Database)--Get Database ID
  IF EXISTS(SELECT * FROM tempdb.sys.objects WHERE name='Indexes') 
  BEGIN --Delete Temp Table if exists, then create
    DROP TABLE TempDb.dbo.Indexes
  END

CREATE TABLE TempDb.dbo.Indexes(IndexTempID INT IDENTITY(1,1),SchemaName NVARCHAR(128),TableName NVARCHAR(128),IndexName NVARCHAR(128),IndexFrag FLOAT)
EXEC ('USE '+@Database+';
INSERT INTO TempDb.dbo.Indexes(TableName,SchemaName,IndexName,IndexFrag)
SELECT OBJECT_NAME(ind.OBJECT_ID) AS TableName,sch.name,ind.name IndexName,indexstats.avg_fragmentation_in_percent
FROM sys.dm_db_index_physical_stats('+@DbID+', NULL, NULL, NULL, NULL) indexstats
INNER JOIN sys.indexes ind ON ind.object_id = indexstats.object_id AND ind.index_id = indexstats.index_id
INNER JOIN sys.objects obj on obj.object_id=indexstats.object_id
INNER JOIN sys.schemas as sch ON sch.schema_id = obj.schema_id
WHERE indexstats.avg_fragmentation_in_percent > 10 AND indexstats.index_type_desc<>''HEAP''
ORDER BY indexstats.avg_fragmentation_in_percent DESC')--Get index data and fragmentation, set the percentage as high or low as you need

DECLARE @IndexTempID BIGINT=0,@SchemaName NVARCHAR(128),@TableName NVARCHAR(128),@IndexName NVARCHAR(128),@IndexFrag FLOAT
SELECT * FROM TempDb.dbo.Indexes --View your results, comment out if not needed...

-- Loop through the indexes
WHILE @IndexTempID IS NOT NULL 
  BEGIN
    SELECT @SchemaName=SchemaName,@TableName=TableName,@IndexName=IndexName,@IndexFrag=IndexFrag FROM TempDb.dbo.Indexes WHERE IndexTempID=@IndexTempID
    IF @IndexName IS NOT NULL AND @SchemaName IS NOT NULL AND @TableName IS NOT NULL 
    BEGIN
      IF @IndexFrag<30. 
      BEGIN --Low fragmentation can use re-organise, set at 30 as per most articles
        PRINT 'USE '+@Database+'; ALTER INDEX ' + @IndexName + N' ON ' + @SchemaName + N'.' + @TableName + N' REORGANIZE'
        EXEC('USE '+@Database+'; ALTER INDEX ' + @IndexName + N' ON ' + @SchemaName + N'.' + @TableName + N' REORGANIZE')
      END
    ELSE 
      BEGIN --High fragmentation needs re-build
        PRINT 'USE '+@Database+'; ALTER INDEX ' + @IndexName + N' ON ' + @SchemaName + N'.' + @TableName + N' REBUILD'
        EXEC('USE '+@Database+'; ALTER INDEX ' + @IndexName + N' ON ' + @SchemaName + N'.' + @TableName + N' REBUILD')
      END
    END

    SET @IndexTempID=(SELECT MIN(IndexTempID) FROM TempDb.dbo.Indexes WHERE IndexTempID>@IndexTempID)
  END
END

DROP TABLE TempDb.dbo.Indexes

GO