SQL Server 2012 supports direct execution of CLR assemblies. It is not optimized to do so; it just supports this capability.
0 value for
clr enabled indicates that these CLR assemblies are not allowed to run on this SQL Server instance. A value of
1 allows this type of execution. The setting takes effect immediately after
sp_configure is run, with no restart of the SQL Server instance required. When
RECONFIGURE is run and the run value of the
clr enabled option is changed from
0, all application domains containing user CLR assemblies are immediately
unloaded. CLR assembly execution is not supported under lightweight pooling, so you must disable one of two options:
clr enabled or
lightweight pooling ...