Hi Jason!
So I played around a bit and couldn't find any problems with stopping the SQL Server -- you just lose the ability to store and query alarms and events to/from the SQL database. Alarms are stored in a temporary cache by Citadel until a new connection can be made with the SQL Server, so I'm not sure what long term consequences of this may be.
Doug M
Applications Engineer
National Instruments
For those unfamiliar with NBC's The Office, my icon is NOT a picture of me 🙂