SQL Server 2008 R2 (SQL Server 10.5) :
1.SQL Server 2008 R2 is codenamed as Kilimanjaro
2.In SQL Server 2008 R2 , rebooting is requisite for OS patching , hence server down time is high
3.SQL Server 2008 R2 does not have this feature of availability groups, hence fast recovery is not possible.
4.SQL Server 2008 R2 is slow compared to SQL Server 2012.
5.However buffer rate is less because there is no data redundancy in SQL Server 2008 R2
6.Data visualization is not supported in SQL Server 2008 R2
7.Spatial features are not supported more in SQL Server 2008 R2. Instead a traditional way for geographical elements have been set in SQL Server 2008 R2.
SQL Server 2012 (SQL Server 11) :
1.SQL Server 2012 is codenamed as Denali
2.In SQL Server 2012, server down time is reduced by 50% , hence OS patching is not rebooting n times.
3.In SQL Server 2012, high availability and disaster recovery factor has been introduced which duplicates the data and rapidly recovers the loss.
4.In SQL Server 2012, the performance is 10 times faster than the predecessor.
5.Buffer rate is high in SQL Server 2012 because of data compression.
6.Data visualization tool is available in SQL Server 2012.This allows snapshots of data.
7.Support for persistent computed columns and extra geographical approach is possible with spatial features in SQL Server 2012.