Hi Everyone
We are migrated a large number of client reports over to Power BI from our SSRS legacy system. So far we have had no issues, until we get to a particularly tricky report that one client requested, with very specific requirements for a pixel perfect PDF exportable report. In the original SSRS report, we have a list control for one group. Within that list is a subreport, which has its own list for another group and then within that a final subreport with its own list. Whilst not a great way of producing the report, the clients wants a single report to produce the layout for the various groups. Its only run once a quarter.
The issue we have is the report does not run in Power BI but does in SSRS. The SQL code has been optimized and runs within a couple of seconds for each iteration of the groups. What I noticed yesterday when running the report in Power BI, the pop-up that appears showing the records processed, it started of super quick for what I think is each iteration, it slowed down each time. I left the report running for 1 hour 45 minutes before cancelling it. The SSRS version takes 38 minutes, which I know is obscene but it works.
So my question is, how does Power BI handle the data coming in for the list control, as it appears to be doing something different to what SSRS would do. Sorry if this is really confusing. Or if anyone has any suggestions on how better to produce a paginated report with multiple levels of grouping\looping, that would be great.
