> But there would be "real benefits": there are significant performance overheads, especially at Facebook's scale, with using an RDBMS compared to something spe

> But there would be "real benefits": there are significant performance overheads, especially at Facebook's scale, with using an RDBMS compared to something specifically written for their use-case. If a different storage system has even, say, 10% better performance overall then that translates to a 10% reduction in hardware-costs, which at Facebook's scale is easily tens-of-millions of dollars per year. And how would you know that? Based on what did you come up with those numbers? I find that hyperbole puts me off discussions of this kind.