SqlCommand.BeginExecuteNonQueryまたはSQLジョブの代替案（asp.net Webページから非同期にストアドプロシージャを呼び出すため）

Aim: Calling a very slow stored procedure (with
parameters) asynchronously from code behind of an asp.net web page
via single function call, and then forgetting about it.

Notes: I tried using
SqlCommand.BeginExecuteNonQuery without calling
SqlCommand.EndExecuteNonQuery (see the code below),
but the stored procedure didn’t run. (I used a tiny stored
procedure to update single field on a table for testing but the
field was not updated. It gets update when I use
SqlCommand.ExecuteNonQuery).

私はストアドプロシージャがいつ終了するのか興味がなく、わからない。 （したがって、
SqlCommand.EndExecuteNonQuery
の呼び出しが完了するまで待つことはできません）。

Situation: After some research, I found out
that sql jobs can be used for this purpose. And for the sp
parameters; I can store them in a table and then sp can read them.
However I don’t know if this is the right approach to my problem (I
am new to SQL world). I hope you can comment on usage of an sql job
for this purpose, or suggest alternatives. Thanks.

コード：

    using (SqlConnection connection = new SqlConnection(
        @"Data Source=XXXMSSQL2008R2;Initial Catalog=YYY;Integrated Security=True"
        + ";Asynchronous Processing=true"))
    {
        connection.Open();
        SqlCommand cmd = new SqlCommand("spTestProcedure", connection);
        cmd.CommandType = CommandType.StoredProcedure;
        cmd.Parameters.Add(new SqlParameter("@pText", DateTime.Now.ToString()));
        cmd.BeginExecuteNonQuery(); //Doesn't work.
        //cmd.ExecuteNonQuery();//This works.
    }