A vendor that provides services to our company allows us to use their implementation of Report Builder (not 2.0) to analyze their data (They're using SSRS 2005). We've run into a situation where most of the reports we've built no longer actually return results-- i.e., the reports never finish. Reports that used to complete in a couple of minutes are now still running after several hours, even though nothing about the report definition/criteria has changed.
It doesn't matter if we access the reports via Report Builder or the Report Manager. The reports don't finish for us. Strangely, when then vendor runs our reports, they work just fine.
I've done some "testing" by limiting the filter criteria of the reports. I've noticed that changing a date parameter to look for a specific date yields a quick response for the report to complete; but, if I open the date filter to be "on or after xx/xx/xxxx" then the report won't finish (which is unfortunate since this is the correct filter definition we need).
Its my hunch that the vendor's data models exposed in Report Builder have a bad join that has a many-to-many join in it somewhere. Since I don't have access to the actual model definition, I can't prove this.
I'm the lead at my company on SSRS 2005 report design, and we've not encountered this "report never finishes" issue of our own. Consequently, I'm not equipped to diagnose our vendor's performance issue.
Any suggestions on what might be causing this problem and how to fix will be greatly appreciated!