I am not sure of the quantity represented by a lack, but I believe it is a pretty large number. You also say "Dump report." Is this a data feed to something else or for an analyst to use as a data source or a report? If it is a report, then I would say the only way to fix your problem is to increase capacity on your server, or reduce the number of rows returned. If it is just a data feed, move the whole thing to SQL Server and forget about SSRS in this instance.