Yes, you will loose all the existing database means policies, configuration etc.
Best Practices guide to moving the Symantec Endpoint Protection Manager SQL Server database from an existing SQL Server database to a new SQL Server database
http://www.symantec.com/docs/TECH104723http://www.symantec.com/docs/TECH104723
Best Practices guide to moving the Symantec Endpoint Protection Manager SQL Server database from an existing SQL Server database to a new SQL Server databas
http://www.symantec.com/docs/TECH167300