What's your opinion about SQL server as a strategy-game's logic engine?

I am about to make a small strategy-game. My aim is, that most of the calculation would be done either on a dabase engine, or paralellized with linq, like AI decisions and so. Should I choose to include online play, it would certanly run on some sort of (99.9% it's going to be MS) Database engine. But could I also use it for single-player (or stick with linq)? I have found the express (or maybe compact) edition, that should be free to distribute. What do you think? Would it be too problematic to have the user install it (I mean automatically throug steam)? Has anyone thought about this? Also it would probably work on linux, since MS SQL server is out on linux... so I could add it to that version too (I dont bother with mac, since I don't have one I could not debug on it). Unity would really only give the front-end for the game. Something it is really good for though.