Question

我有一个Sql过程，它从表中选择记录，如果匹配insert到另一个表。它如下

    CREATE PROCEDURE [dbo].[MarkCopyData] 
@copyDataOperationId int,
@countryCode nvarchar(50),
@batchCount int,@batchId int,@jobId int
    AS
    BEGIN
DECLARE @TableObjectId AS Int;
SET @TableObjectId = OBJECT_ID('Table1');
INSERT INTO  
    Table2(
            TableObjectId, 
            SourcePrimaryKey, 
            DestinationCopyOperationId, 
            IsModifiedAftertCopied,IsDeleted,BatchId,JobId)

    SELECT TOP (@batchCount) @TableObjectId, tbl1.pkid, @copyDataOperationId,      0,0,@batchId,@jobId
    FROM [dbo].[Table1] AS tbl1
    Inner join [dbo].[Country] AS C on C.CountryId =  tbl1.fkid
    LEFT OUTER JOIN Table2 tbl2 on (tbl2 .SourcePrimaryKey = tbl1.pkid and tbl2 .TableObjectId = @TableObjectId)
    WHERE C.CountryCode = @countryCode AND tbl2.DestinationCopyOperationId IS NULL
    SELECT @@ROWCOUNT
    END
    GO

任何人都可以提出改善此程序性能的提示

Answer 1

如果没有看到基础表的结构，就无法提供帮助。尝试使用CTRL + L查看估计的执行计划。您可能想要评论CREATE PROCEDURE内容，它会使计划更容易阅读。

通常情况下，创建一两个索引就是一个例子。

您可能会发现将C.CountryCode = @countryCode从WHERE子句移动到INNER JOIN可能会有所帮助。通常，您希望在开始执行外连接之前过滤结果集。

SELECT TOP (@batchCount) @TableObjectId, tbl1.pkid, @copyDataOperationId,0,0,@batchId,@jobId
FROM [dbo].[Table1] AS tbl1
Inner join [dbo].[Country] AS C on C.CountryId =  tbl1.fkid AND C.CountryCode = @countryCode
LEFT OUTER JOIN Table2 tbl2 on (tbl2 .SourcePrimaryKey = tbl1.pkid and tbl2 .TableObjectId = @TableObjectId)
WHERE tbl2.DestinationCopyOperationId IS NULL

提高Sql程序的性能

1 个答案: