Recently I had to install SQL SERVER 2008 R2 BIDS on top of a machine which already had SQL SERVER 2008 BIDS. Since SQL SERVER supports side by side installation of same/different versions (in fact we have BIDS 2005 & 2008 installed in a machine), I thought this should not have any issue. However when I started installing the R2 BIDS, the rule check generated a warning
Rule “SQL Server 2008 and SQL Server 2008 R2 Shared Component Upgrade Rule” generated a warning.
There are one or more shared components of SQL Server 2008 installed on the machine. Be aware that installing SQL Server 2008 R2 shared components will automatically upgrade the existing shared components.
On clicking the “View Detailed Report” hyperlink, at the top, it opened a htm page which details out the rule check and its result. At the end of the table, the rule “SharedComponentsUpgradeRule” raised a warning saying that all shared components will be upgraded to the higher version.
My colleague shared this link which explained what can/cannot be installed side by side. In short, SQL SERVER has some shared components not just with same versions but even across different versions. The above link lets us what are these shared components and what happens when side by side install happens. People planning for side by side installation should certainly review this link.