We have a 2008 R2 native installation of SSRS. I usually develop reports in one big visual studio report server project and manually upload the .rdl files via the front-end of the SSRS web site. However, I've noticed that you can build debug/release versions of the .rdl files. The only difference I've noticed so far is that the compiled .rdl is 2KB bigger than the "raw" .rdl – no performance gains noticed, etc.
Does anybody know the difference between using a raw .rdl and a compiled .rdl?
Best Answer
There are no raw vs compiled rdl in Visual Studio.
The confusion comes from other project types in Visual Studio, because every .NET developer know that there is a difference between a dll/exe if you compile it with or without the "Optimize code" checkbox.
Even if the term "build" is present in the SSRS documentation, it is easier to consider that RDL reports are not built (at least not before deployment), because building a report is a totally different thing than building a .NET application.
Source: Publishing Reports to a Report Server
Here, built should be seen as a validity check.
EDIT 2017-10-25: but not only, see the comment below from Michael Edenfield.
When are reports compiled?
When you view the report.
Source: Reporting Services Reports (SSRS)
Here is a diagram showing an overview of the report processing:
Source: Reporting Services Concepts (SSRS)
What are the Debug/Release configurations used for?
In solution/project configurations, you can store deployment settings, such as the target server URL, report path and so on.
You can use the standard one, for example use Debug to publish reports to a test SSRS server, and Release to publish reports to a production SSRS server.