SQL Server 2008 Service Pack 3 Cumulative Update 9, build 10.00.5829 is released with just 3 fixes
There is no corresponding Cumulative Update for SQL Server 2008 RTM, SP1, or SP2, because those service pack levels are retired.
- SQL Server 2008 RTM was retired on April 13, 2010,
- SQL Server 2008 SP1 was retired on September 19, 2011,
- SQL Server 2008 SP2 was retired on September 17, 2012.
If you are running SQL Server 2008, then you should be on Service Pack 3 . I doubt whether Microsoft will release a SQL Server 2008 Service Pack 4.
Mainstream support for both SQL Server 2008 and 2008 R2 is still scheduled to end on January 14, 2014.
