Does Sql Server 2008 support Database Sharding
No, SQL Server doesn't support sharding. SQL Server scales up not out.

This applies to RDBMS in general:


CAP theorem says you can have at most 2 of C, A and P.
RDBMS are ACID compliant which is the point of using them


The "C" in both acronyms is "Consistency" and sharding sacrifices "Consistency"
So generally sharding and consistency are mutually exclusive

There are exceptions (more or less) of course. Some examples:


Oracle RAC which is expensive and tricky
MySQL replication which is not Consistent
MySQL cluster sacrifices Availability in case of node failure, and can be set to prioritize either consistency or availability