I am being told WSUS 4.0 cannot be ran on SQL server 2008 R2, so they could only install and use WSUS version 3.0.
(Pedantically speaking this is true because there is no such beast as "WSUS 4".)
However, WSUS v6.2 (Windows Server 2012) and WSUS v6.3 (Windows Server 2012 R2) can most certainly be installed on SQL Server 2008 R2, and the official documentation is at
http://technet.microsoft.com/en-us/library/hh852344.aspx
However, the *preferred* installation methodology, unless you've expressly chosen to use a remote SQL Server, is to use the Windows Internal Database feature which is built into Windows Server 2012 and 2012 R2.
Lawrence Garvin, M.S., MCSA, MCITP:EA, MCDBA
SolarWinds Head Geek
Microsoft MVP - Software Packaging, Deployment & Servicing (2005-2014)
My MVP Profile: http://mvp.microsoft.com/en-us/mvp/Lawrence%20R%20Garvin-32101
http://www.solarwinds.com/gotmicrosoft
The views expressed on this post are mine and do not necessarily reflect the views of SolarWinds.