Question

I just got a code handed over to me. The code is written in C# and it inserts realtime data into database every second. The data is accumulated in time which makes the numbers big.

The data is updated within the second many times then at the end of the second result is taken and inserted.

We used to address the dataset rows directly within the second through the properties. For example many operations like this one ‘datavaluerow.meanvalue += mean; could take place.
we figured out that this is degrading the performance after running the profiler becuase of the internal casting done so we created 2d array of decimals on which the updates are carried out then the values are assigned to the datarows only at the end of the second.
I ran a profiler and found out that it is still taking a lot of time (although less than the time spent accessing datarows frequently when added up).

The code that is exectued at the end of the second is as follows

public void UpdateDataRows(int tick)
{
  //ord
  //_table1Values is of type decimal[][]
  for (int i = 0; i < _table1Values.Length; i++)
  {
    _table1Values[i][(int)table1Enum.barDateTime] = tick;
    table1Row[i].ItemArray = _table1Values[i].Cast<object>().ToArray();

  }
  // this process is done for other 10 tables            
}

Is there a way to further improve this approach.

Answer 1

One obvious question: why do you have a 2D array of decimals when you’re only updating them with integers? Could you get away with an int[][] instead?

Next, why are you accessing (int)table1Enum.barDateTime on each iteration? Given that there’s a conversion involved there, you may find it helps if you extract that out of the loop.

However, I suspect the majority of the time is going to be spent in _table1Values[i].Cast<object>().ToArray(). Do you really need to do that? Taking a copy of the decimal[] (or int[]) would be faster than boxing every value on every iteration on every call – and then creating another array.