I've heard so many horror stories about late night mistakes like forgetting about WHERE part of UPDATE or DELETE queries that I don't think that SQL database is any safer than filesystem in this respect. In reallity no matter what database backend you use backups are must have for important data.

Jepp! Two years ago I damaged all ongoing projects of my company from home by forgetting a where-clause; the backups were not @home :-)

pure luck I wasn't killed in a car-crash that day...while we hurried to the companys rooms

So while typos aren't an argument for DBMS :-), an rdbms is the way to go if scaleabilty matters, and it matters for every project not typed at the console-prompt (and somtimes even there...)

regards,
tomte