The Communications Web site, http://cacm.acm.org, features more than a dozen bloggers in the BLOG@CACM community. In each issue of Communications, we'll publish excerpts from selected posts. twitter Follow us on Twitter at http://twitter.com/blogCACM Michael Stonebraker considers several performance arguments in favor of NoSQL databases�and finds them insufficient. http://cacm.acm.org/blogs/blog-c