DBCC dllname (FREE) (Transact-SQL)
Unloads the specified extended stored procedure DLL from memory.
Applies to: SQL Server (SQL Server 2008 through current version).
When an extended stored procedure is executed, the DLL remains loaded by the instance of SQL Server until the server is shut down. This statement allows for a DLL to be unloaded from memory without shutting down SQL Server. To display the DLL files currently loaded by SQL Server, execute sp_helpextendedproc
When a valid DLL is specified, DBCC dllname (FREE) returns:
DBCC execution completed. If DBCC printed error messages, contact your system administrator.