Hi I am using .NET and SSRS 2008 for report generation. I have come across a scenario where there are around 10 lacs record in the tables from which i am generating the data. It requires to show these many records in the report. Problem here is stored proc execution takes long time so report timesout and throws an error. Is it possible to render the report for partially selected data then page by page as the data is getting fetched it will be shown in the report.
Is it the rendering that is the problem, or does the report calculate the data at runtime and that is slow? You could always offload the data retrieval/calculation, filling an interim "Reporting" table that you then offer up to the report. That way, the expensive filling of the table can be run in out of office hours and no-one minds it filling slowly. The table should then be quicker to query when the report is loaded.
Asynchronous rendering is not possible because of the way SSRS compiles reports. Before any processing or rendering is done, Reporting Services retrieves all the data to be used in the report. You'll have to tune the stored proc, retrieve less data, or crank up the timeout interval to fix the problem.