SQL MERGE 每秒 2,000 辆车时 CPU 使用率高

Question

这里有两个问题。

1) 有谁知道为什么我在每秒合并 2,000 辆车时 CPU 使用率很高？

2) 很好奇，有没有办法在不占用大量 CPU 的情况下每秒合并 10,000 辆车？

//Table & Index syntax...
CREATE TABLE [dbo].[Dealer_SalesVehicles](
    [RawID] [bigint] IDENTITY(1,1) NOT NULL,
    [AccountID] [bigint] NOT NULL,
    [StockNumber] [nvarchar](50) NOT NULL,
    [Vin] [nvarchar](30) NOT NULL,
    [Year] [nvarchar](50) NOT NULL,
    [Make] [nvarchar](50) NOT NULL,
    [Model] [nvarchar](50) NOT NULL,
    [Style] [nvarchar](80) NOT NULL
 CONSTRAINT [PK_Dealer_SalesVehicles_AccountId_StockNumber_Vin] PRIMARY KEY CLUSTERED 
(
    [AccountID] ASC,
    [StockNumber] ASC,
    [Vin] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 100) ON [PRIMARY]
) ON [PRIMARY]

//Sql Query...
var sqlAsk = "";
var rowAffected = 0;
var errorSqlParameters = new List<Tuple<string, string>>(); ;

using (var dbConnection = new SqlConnection(this._databaseConnectionString))
{
   using (var dbCommand = dbConnection.CreateCommand())
   {
       sqlAsk = "";
       sqlAsk += " MERGE ";
       sqlAsk += "     TOP (1)[dbo].[Dealer_SalesVehicles] WITH(HOLDLOCK) AS t ";
       sqlAsk += "     USING ";
       sqlAsk += "         (SELECT ";
       sqlAsk += "             @parmAccountId, @parmStockNumber, @parmVin ";
       sqlAsk += "         ) ";
       sqlAsk += "         AS s ";
       sqlAsk += "         ( ";
       sqlAsk += "             [AccountID], [StockNumber], [VIN] ";
       sqlAsk += "         ) ";
       sqlAsk += "     ON(t.[AccountId] = s.[AccountId] AND t.[StockNumber] = s.[StockNumber] AND t.[Vin] = s.[Vin]) ";
       //#-- if matched, update existing record if right conditions are met(see Description in header)...
       sqlAsk += " WHEN MATCHED AND(t.[AccountId] = s.[AccountId]) AND t.[StockNumber] = s.[StockNumber] AND(t.[Vin] = s.[Vin]) THEN ";
       sqlAsk += "     UPDATE SET ";
       //AccountID...
       //StockNumber...
       //VIN...
       sqlAsk += "         t.[Year] = @parmYear, ";
       sqlAsk += "         t.[Make] = @parmMake, ";
       sqlAsk += "         t.[Model] = @parmModel, ";
       sqlAsk += "         t.[Style] = @parmStyle ";
       //#-- if not matched, add new record and set return values...
       sqlAsk += " WHEN NOT MATCHED THEN ";
       //#--http://stackoverflow.com/questions/1609208/need-help-with-the-merge-statement...
       //#--(Cannot use "s." or "t." here, for source or target table - name - abbreviation cuz "Columns name in the insert list can only refer to the target table, so the parser doesn't expect to see a table alias there, wouldn't know how to resolve it. It sees "column1", it knows it belongs to the target table. It sees "table1.column1", it doesn't know what "table1" means. "table1" is out of scope, so to speak")...
       sqlAsk += "     INSERT( ";
       //RawID...
       sqlAsk += "         [AccountID], [StockNumber], [VIN], ";
       sqlAsk += "         [Year], [Make], [Model], [Style] ";
       sqlAsk += "     ) ";
       sqlAsk += "     VALUES( ";
       sqlAsk += "         @parmAccountId, @parmStockNumber, @parmVin, ";
       sqlAsk += "         @parmYear, @parmMake, @parmModel, @parmStyle ";
       sqlAsk += "     ) ";
       sqlAsk += " ; ";  //#--required semicolon separator for MERGE....

       dbCommand.CommandTimeout = 60;
       dbCommand.CommandText = sqlAsk;
       dbCommand.Parameters.Clear();
       dbCommand.Parameters.Add(new SqlParameter("@parmAccountId", SqlDbType.BigInt)).Value = parmSqlSalesVehicleRequest.DealerBranchAccountId;
       dbCommand.Parameters.Add(new SqlParameter("@parmStockNumber", SqlDbType.NVarChar)).Value = parmSqlSalesVehicleRequest.StockNumber;
       dbCommand.Parameters.Add(new SqlParameter("@parmVin", SqlDbType.NVarChar)).Value = parmSqlSalesVehicleRequest.Vin;
       dbCommand.Parameters.Add(new SqlParameter("@parmYear", SqlDbType.NVarChar)).Value = parmSqlSalesVehicleRequest.Year;
       dbCommand.Parameters.Add(new SqlParameter("@parmMake", SqlDbType.NVarChar)).Value = parmSqlSalesVehicleRequest.Make;
       dbCommand.Parameters.Add(new SqlParameter("@parmModel", SqlDbType.NVarChar)).Value = parmSqlSalesVehicleRequest.Model;
       dbCommand.Parameters.Add(new SqlParameter("@parmStyle", SqlDbType.NVarChar)).Value = parmSqlSalesVehicleRequest.Style;

       foreach (SqlParameter sqlParameter in dbCommand.Parameters)
       {
           errorSqlParameters.Add(new Tuple<string, string>(sqlParameter.ParameterName, sqlParameter.Value.ToString()));
       }

       if (dbConnection.State == ConnectionState.Open) { dbConnection.Close(); }

       await dbConnection.OpenAsync();

       rowAffected = await dbCommand.ExecuteNonQueryAsync();
   }
}

Answer 1

创建单个存储过程：

CREATE PROCEDURE dbo.usp_Add
(
    @parmAccountId ...,
    @parmStockNumber
)
AS BEGIN

    SET NOCOUNT ON;

    MERGE TOP(1) dbo.Dealer_SalesVehicles WITH (HOLDLOCK) t
    USING (
        SELECT [AccountID] = @parmAccountId,
               [StockNumber] = @parmStockNumber,
               [VIN] = @parmVin
    ) s ON t.[AccountId] = s.[AccountId]
        AND t.[StockNumber] = s.[StockNumber]
        AND t.[Vin] = s.[Vin]
    WHEN MATCHED
        THEN UPDATE
            SET
                t.[year] = @parmYear,
                t.[Make] = @parmMake,
                t.[model] = @parmModel,
                t.[style] = @parmStyle
    WHEN NOT MATCHED
        THEN INSERT ([AccountID], [StockNumber], [VIN], [year], [Make], [model], [style])
        VALUES (@parmAccountId, @parmStockNumber, @parmVin, @parmYear, @parmMake, @parmModel, @parmStyle);

END
GO

并从您的代码中执行此 SP。