We have some DB scripts that need to be migrated from SQL Server 2008 R2 back to 2005, often scripts created in SQL Server 2008 / 2008 R2 won't run on a SQL Server 2005 installation (which some customers still use).
So my question: from your experience/knowledge, is this really necessary, or does setting the compatibility level back to 90 on SQL Server 2008 (2008 R2) fix the issue of unnoticed breaking scripts in SQL Server 2005? MSDN says "compatibility level provides only partial backward compatibility with earlier versions of SQL Server ", so I'm unsure here.
I would like a concrete list of “features will pass compatibility level 90 but break on SQL Server 2005" or link. If the list is short list, we could convert that to an internal "don't do that!" list and save a lot of work.