WorkSheets = all your Worksheets private void deleteUnUsedWorksheets() { foreach (Excel._Worksheet sheet in WorkSheets) { if (IsWorkbookEmpty(sheet)) sheet.Delete(); } } private bool IsWorkbookEmpty(Excel._Worksheet sheet) { ExcelRange = sheet.UsedRange; if (ExcelRange.Columns.Count > 1 | ExcelRange.Rows.Count > 1 | ExcelRange.Count > 1) return false; else return true; } You dont have to check each cell. Its senseless and you throw a lot of memory Don`t throw a catch if its only a return false!

Forgot to mention it, but yes, it's a big concern. I'm extracting almost 120GB of files stored in aprox. 400000 BLOBs. :) But thanks for suggestions :)

As Asfield said, join the 2 tables so that you retrieve them once. I would add to what he said is that you probably want to add paging. So instead of processing 1 M record, you can process 1000 record at a time etc..

Thomas ST wrote: That is a lot of hours wasted... We've all done this sort of thing! CCC solved so far: 2 (including a Hard One!)

What about using an overload that way if it is passed in as something other then a valid DateTime object it will get treated by the overlaoded method and there you can try parsing it manually: [WebMethod] public ReturnList GetList(string id, string fromDate) { // overlaod // your parsing logic } [WebMethod] public ReturnList GetList(string id, System.DateTime fromDate) { // Original function } Worth a try ... hth