我在这里真的很糊涂。
我将大约200万行导入我的azure sql数据库。当我使用合并技术只插入没有重复的行时，我创建了一个临时表，在其中放置我的值。我的代码和脚本如下所示。

public async Task BulkImportWithoutDuplicates(DataTable reader)
{
    var tableName = "##tempImport";

    using (var connection = new SqlConnection(sqlCOnn.ConnectionString))
    {
        using (SqlCommand command = new SqlCommand("", sqlCOnn))
        {
            try
            {
                sqlCOnn.Open();

                // Creating temp table on database
                command.CommandText = Scripts.GetTempTableScript();
                command.ExecuteNonQuery();

                // Bulk insert into temp table
                using (SqlBulkCopy b = new SqlBulkCopy(conString, SqlBulkCopyOptions.TableLock))
                {
                    b.BulkCopyTimeout = 0;
                    b.BatchSize = reader.Rows.Count;
                    b.DestinationTableName = tableName;
//dataTable 

                    await b.WriteToServerAsync(reader);

                    b.Close();
                 }

                 // Updating destination table, and dropping temp table
                 command.CommandText = Scripts.GetMergeScript();
                 var rows = command.ExecuteNonQuery();
             }
             catch (Exception ex)
             {
                 // Handle exception properly
             }
             finally
             {
                 connection.Close();
             }
        }
    }
}

public static string GetTempTableScript()
{
    return $@" 
            IF OBJECT_ID('tempdb.dbo.##tempImport', 'U') IS NOT NULL
            BEGIN
            DROP TABLE ##tempImport;
            END

              CREATE TABLE ##tempImport ( ... all the columns);";
}

public static string GetMergeScript()
{
    return $@"MERGE INTO dbo.Data AS target
              USING ##tempImport AS source
                ON (source.TransactionId = target.TransactionId AND source.UserId = target.UserId)

                WHEN NOT MATCHED THEN
                    INSERT (Start, Spend, UserId, Product, Shop, ClientId, UploadDataId, UniqueId, TransactionId, q, cq, c2)
                        VALUES (source.Start, source.Spend, source.UserId, source.Product, source.Shop, 
                source.ClientId, source.UploadDataId, source.UniqueId, source.TransactionId, source.q, source.c1, source.c2);

               ";
        }

我真的不明白为什么要花很长时间才能完成。我等了24分钟，直到它被单独添加到临时桌上。
我正在读这篇文章，似乎不会花太长时间。https://www.adathedev.co.uk/2011/01/sqlbulkcopy-to-sql-server-in-parallel.html?m=1
我做错什么了？如何提高速度？
我两个都试过了 IDataReader 以及 DataTable 但这两个都不适合我。。。