How to debug a report in webi

Hi Every One,

1) How to debug (debuging steps )in a report in boxir2 webi based report.can any body help me out .

2)How we do the performance and tuning in the report level.

3)Aggregate awareness is possible to apply in report level or in universe level.If possible where we can find that option in webi..

Please help me out

Thanks in advance