I'm using SQL Server Reporting Services and the report designer that comes with Visual Studio. I've got a really big report. It's actually so large that Visual Studio hangs (sometimes for hours at a time) or just crashes when I make changes.

There is preciously little I can do to solve the problem, so I've decided to just move the bottom half of the report into a sub-report. So, I started with one enormous, unresponsive report and ended with two small, manageable reports -- surprisingly, this actually works.

One problem: my subreport uses the same data as my main report. Right now, it populates its dataset by re-querying the database. The extra round-trip to the database causes the report to take twice as long to generate; up from 45 minutes to 1 1/2 hours to generate.

I'd like to avoid hitting the database again, and instead use the same dataset in both reports.

How can I share or pass a dataset between a report and subreport?