> Why not look at it from a different perspective. Instead of saving all the
> records, computing the statistics and then deleting the records, why not
> simply keep a running calculation based on available data? Or keep running
> totals of what you need and compute the stats when needed? If the data isn't
> going to be kept anyway, does it really matter if the records get saved? If
> you update fields that keep running totals of available/needed information,
> you can always run statistics based on those at any time.

thanks, i was already thing about this, THE problem is that several users work on the data... for exemple several users can access the table xxx and for every access we add a row in access table to at the end of the days know how many time the table xxx was accessed. if for every access i update the column number_of_access then i will go in deadlock or low performance du to waiting the deadlock to be release :(