What seems like one person's "good" natural key can make another person wish like the dickens that that somebody had used a synthetic key, eh?
I was happily blogging away (elsewhere), when I encountered this fun little, specific (but unhelpful) error from Windows Live Writer:
Server Error 0 Occurred
The post could not be added
After roundly cursing WLW, flaming my ISP for dorking around with my shared hosting environment and sundry other possible root causes, I came to learn that apparently the text of that error is what Community Server spews when you try to add another post with a title that's already been used once in your blog, and it's not WLW's fault at all (or the ISP's et al).
Now I can imagine the design session that resulted in the Community Server team or whoever designed the Metablog API deciding that the title of a blog post made for a "great key" value, but... Am I (the user) supposed to actually remember what titles I've used for all my previous posts? And figure out from that LAME error message that all I need to do is change the title by ONE lousy character just to get past the error!?!
#@$&ing bad data model!!!