MS SQL临时表更新失败 [英] MS SQL temporal table update failure

问题描述

我找不到任何解释可以解释为什么在调用执行插入或更新的SP时，取决于在临时表上是否已经存在记录的原因

I cant find anything to explain why when calling a SP that does a insert or update depending on if record already exists on a temporal table i get

系统版本表上的数据修改失败'MYDB.dbo.TemporalExample'，因为交易时间早于受影响的记录的期限开始时间.

Data modification failed on system-versioned table 'MYDB.dbo.TemporalExample' because transaction time was earlier than period start time for affected records.

什么意思?它似乎只是在某些时间发生，我想知道是否是因为我运行多线程代码和azure sql只是不喜欢在临时表上相互连接到同一张表?我正在使用实体框架(最新版本)，但我怀疑这是问题所在

what dose that mean ? It only seems to happen some of the time , i wonder if its because im running multi threaded code and azure sql just doesn't like mutual connections to the same table when its a temporal one ? Im going though entity framework (latest version) but i doubt that's the issue

我的宝贝就是这个

create PROCEDURE mysp 
    @ID bigint,
    @a FLOAT,
    @b NVARCHAR(10),
    @c  DECIMAL(19, 4)
AS
    SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED    

    SET NOCOUNT ON    

    BEGIN TRY

        IF EXISTS ( SELECT TOP 1 
                        Id 
                    FROM 
                        my_Temporal_Table WITH (NOLOCK) 
                    WHERE 
                        id = @ID 
                        AND a = @a
                        AND b = @b)
            BEGIN

                UPDATE 
                    my_Temporal_Table
                SET
                    Id = @ID,
                    a = @a,
                    b = @b
                    c = @c
                    DateModified =  GETUTCDATE()
                WHERE 
                    Id = @Id

            END
        ELSE    
            BEGIN

                INSERT INTO 
                    my_Temporal_Table
                        (Id, a, b, c, DateModified)
                VALUES 
                        (@ID, @a, @b, @c , GETUTCDATE())        
            END

    END TRY
    BEGIN CATCH
        DECLARE @ErrorMessage   NVARCHAR(4000),
                @ErrorSeverity  INT,
                @ErrorState     INT

        SELECT 
                @ErrorMessage = ERROR_MESSAGE(),        
                @ErrorSeverity = ERROR_SEVERITY(),
                @ErrorState = ERROR_STATE()

        -- Use RAISERROR inside the CATCH block to return error
        -- information about the original error that caused
        -- execution to jump to the CATCH block.
        RAISERROR (@ErrorMessage, -- Message text.
                   @ErrorSeverity, -- Severity.
                   @ErrorState -- State.
                   )

    END CATCH

更新我的临时表创建脚本:

Update my temporal table creation script :

    CREATE TABLE [Temporal](
    [TemporalId] [bigint] IDENTITY(1,1) NOT NULL,
    [Payment] [decimal](19, 4) NOT NULL,
    [DateModified] [datetime2](7) NOT NULL,
    [SysStartTime] [datetime2](7) GENERATED ALWAYS AS ROW START NOT NULL,
    [SysEndTime] [datetime2](7) GENERATED ALWAYS AS ROW END NOT NULL,
    CONSTRAINT [TemporalId] PRIMARY KEY CLUSTERED ([TemporalId] ASC)
        WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON),
    PERIOD FOR SYSTEM_TIME ([SysStartTime], [SysEndTime])
    )WITH(
    SYSTEM_VERSIONING = ON ( HISTORY_TABLE = [Car2].[TemporalHistory] )
    )

有人可以解释为什么我可能会看到此问题，这意味着什么，更重要的是我如何解决它?

can someone explain why i might see this issue, what it means and more importantly how i can fix it ?

谢谢

推荐答案

所以我解决了……似乎临时表在线程逻辑中不能很好地发挥作用.我怀疑这是因为im并行对表进行了多个并发更新；链接的历史记录表的更新滞后，以至于时间链接会导致失败.使我的代码成为单线程解决了该问题.时态表受制于几乎是一种竞赛条件，这似乎很奇怪?我知道它不是我的代码，因为同一代码对其他表也能正常工作.因此，我想我必须坚持使用单线程逻辑，直到MS修复它

So i worked it out ...it seems that temporal tables don't play well with threading logic. I suspect that because im doing multiple concurrent updates to the table in parallel; the history table that's linked is lagging in its update enough that the time linkage causes a failure. Making my code single threaded fixed the issue. It seems odd that temporal table would be subject to what seems to be almost a race condition ? I know its not my code as the same code works fine for other tables. So I guess I will have to stick to single threaded logic until MS fix it

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