Unity3d and Database and MultiPlayer Games

Hi All,

I have two questions

First

I'm learning Unity3D now and I just want to know what is the best DBMS that works fine with unity? Or how can I choose the DBMS from all alternative that I have (SQL , MySql , etc)

Second

If I'm going to make multi-player online game that will allow different users to connect to main server and update their info's (Positions of players) and so on , what is the servers that I can use to help me in that , I heard about (SmartFox , Electrotank) , I don't know what is the best choice for my game , so please if any one can provide me some useful information about those two things I will be thankful

Thanks in Advance

I am using Photon for my MMO server side apps and I chose to use Raven DB for my database system. Both are easy, fast and cheap to use. I prefer to use Raven because its a document based database which has advantages over relational databases like SQL. Its fairly new and getting good buzz.